@article{garza_werk_berg_faerman_oppenheimer_bordoloi_ellison_2025, title={The CIViL* Survey: The Discovery of a C iv Dichotomy in the Circumgalactic Medium of L* Galaxies}, volume={978}, ISSN={["2041-8213"]}, DOI={10.3847/2041-8213/ad9c69}, abstractNote={Abstract This paper investigates C iv absorption in the circumgalactic medium (CGM) of L ⋆ galaxies and its relationship with galaxy star formation rates. We present new observations from the C iv in L ⋆ galaxies survey (PID # 17076) using the Hubble Space Telescope/Cosmic Origins Spectrograph. By combining these measurements with archival C iv data (46 observations total), we estimate detection fractions for star-forming ( s SFR > 10 −11 yr −1 ) and passive galaxies (sSFR ≤ 10 −11 yr −1 ) to be 72 − 18 + 14 % [21/29] and 23 − 15 + 27 % [3/13], respectively. This indicates a significant dichotomy in C iv presence between L ⋆ star-forming and passive galaxies, with over 99% confidence. This finding aligns with J. Tumlinson et al., which noted a similar dichotomy in O vi absorption. Our results imply a substantial carbon reservoir in the CGM of L⋆ galaxies, suggesting a minimum carbon mass of ≳3.03 × 10 6 M ⊙ out to 120 kpc. Together, these findings highlight a strong connection between star formation in galaxies and the state of their CGM, providing insight into the mechanisms governing galaxy evolution.}, number={1}, journal={ASTROPHYSICAL JOURNAL LETTERS}, author={Garza, Samantha L. and Werk, Jessica K. and Berg, Trystyn A. M. and Faerman, Yakov and Oppenheimer, Benjamin D. and Bordoloi, Rongmon and Ellison, Sara L.}, year={2025}, month={Jan} }
@article{pizzati_hennawi_schaye_schaller_eilers_wang_frenk_elbers_helly_mackenzie_et al._2024, title={A unified model for the clustering of quasars and galaxies at z ≈ 6}, volume={534}, ISSN={["1365-2966"]}, DOI={10.1093/mnras/stae2307}, abstractNote={ABSTRACT Recent observations from the EIGER JWST program have measured for the first time the quasar–galaxy cross-correlation function at $z\approx 6$. The autocorrelation function of faint $z\approx 6$ quasars was also recently estimated. These measurements provide key insights into the properties of quasars and galaxies at high redshift and their relation with the host dark matter haloes. In this work, we interpret these data building upon an empirical quasar population model that has been applied successfully to quasar clustering and demographic measurements at $z\approx 2\!-\!4$. We use a new, large-volume N-body simulation with more than a trillion particles, FLAMINGO-10k, to model quasars and galaxies simultaneously. We successfully reproduce observations of $z\approx 6$ quasars and galaxies (i.e. their clustering properties and luminosity functions), and infer key quantities such as their luminosity–halo mass relation, the mass function of their host haloes, and their duty cycle/occupation fraction. Our key findings are (i) quasars reside on average in $\approx 10^{12.5}\, {\rm M}_{\odot }$ haloes (corresponding to $\approx 5\sigma$ fluctuations in the initial conditions of the linear density field), but the distribution of host halo masses is quite broad; (ii) the duty cycle of (UV-bright) quasar activity is relatively low ($\approx 1~{{\ \rm per\ cent}}$); (iii) galaxies (that are bright in [O iii]) live in much smaller haloes ($\approx 10^{10.9}\, {\rm M}_{\odot }$) and have a larger duty cycle (occupation fraction) of $\approx 13~{{\ \rm per\ cent}}$. Finally, we focus on the inferred properties of quasars and present a homogeneous analysis of their evolution with redshift. The picture that emerges reveals a strong evolution of the host halo mass and duty cycle of quasars at $z\approx 2\!-\!6$, and calls for new investigations of the role of quasar activity across cosmic time.}, number={4}, journal={MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY}, author={Pizzati, Elia and Hennawi, Joseph F. and Schaye, Joop and Schaller, Matthieu and Eilers, Anna-Christina and Wang, Feige and Frenk, Carlos S. and Elbers, Willem and Helly, John C. and Mackenzie, Ruari and et al.}, year={2024}, month={Oct}, pages={3155–3175} }
@article{bordoloi_simcoe_matthee_kashino_mackenzie_lilly_eilers_liu_depalma_yue_et al._2024, title={EIGER IV. The Cool 104 K Circumgalactic Environment of High-redshift Galaxies Reveals Remarkably Efficient Intergalactic Medium Enrichment}, volume={963}, ISSN={["1538-4357"]}, DOI={10.3847/1538-4357/ad1b63}, abstractNote={Abstract We report new observations of the cool diffuse gas around 29, 2.3 < z < 6.3 galaxies using deep JWST/NIRCam slitless grism spectroscopy around the sight line to the quasar J0100+2802. The galaxies span a stellar mass range of 7.1 ≤ log M ∗ / M ⊙ ≤ 10.7 , and star formation rates (SFRs) of − 0.1 < log SFR/ M ⊙ yr −1 < 2.3. We find galaxies for seven Mg ii absorption systems within 300 kpc of the quasar sight line. The Mg ii radial absorption profile falls off sharply with radius, with most of the absorption extending out to 2–3 R 200 of the host galaxies. Six out of seven Mg ii absorption systems are detected around galaxies with log M ∗ / M ⊙ > 9. The Mg ii absorption kinematics are shifted from the systemic redshifts of host galaxies with a median absolute velocity ≈ 135 km s −1 and standard deviation ≈ 85 km s −1 . The high kinematic offset and large radial separation ( R > 1.3 R 200 ), suggest that five out of the seven Mg ii absorption systems are not gravitationally bound to their host galaxy. In contrast, most of the cool circumgalactic medium at z < 1 is gravitationally bound. The high incidence of unbound Mg ii gas in this work suggests that toward the end of reionization, galaxy halos are in a state of remarkable disequilibrium, and are highly efficient in enriching the intergalactic medium. The two strongest Mg ii absorption systems are detected at z ∼ 4.22 and 4.5, the former associated with a merging galaxy system and the latter associated with three kinematically close galaxies. Both of these galaxies reside in local galaxy overdensities, indicating the presence of cool Mg ii absorption in two “protogroups” at z > 4.}, number={1}, journal={ASTROPHYSICAL JOURNAL}, author={Bordoloi, Rongmon and Simcoe, Robert A. and Matthee, Jorryt and Kashino, Daichi and Mackenzie, Ruari and Lilly, Simon J. and Eilers, Anna-Christina and Liu, Bin and Depalma, David and Yue, Minghao and et al.}, year={2024}, month={Mar} }
@article{yue_eilers_simcoe_mackenzie_matthee_kashino_bordoloi_lilly_naidu_2024, title={EIGER. V. Characterizing the Host Galaxies of Luminous Quasars at z ≳ 6}, volume={966}, ISSN={["1538-4357"]}, DOI={10.3847/1538-4357/ad3914}, abstractNote={Abstract We report JWST/NIRCam measurements of quasar host galaxy emissions and supermassive black hole (SMBH) masses for six quasars at 5.9 < z < 7.1 in the Emission-line galaxies and Intergalactic Gas in the Epoch of Reionization (EIGER) project. We obtain deep NIRCam imaging in the F115W, F200W, and F356W bands, as well as F356W grism spectroscopy of the quasars. We use bright unsaturated stars to construct models of the point-spread functions (PSFs) and estimate the errors of these PSFs. We then measure or constrain the fluxes and morphology of the quasar host galaxies by fitting the quasar images as a point source plus an exponential disk. We successfully detect the host galaxies of three quasars, which have host-to-quasar-flux ratios of ∼1%–5%. Spectral energy distribution fitting suggests that these quasar host galaxies have stellar masses of M * ≳ 10 10 M ⊙ . For quasars with host galaxy nondetections, we estimate the upper limits of their stellar masses. We use the grism spectra to measure the H β line profile and the continuum luminosity, then estimate the SMBH masses for the quasars. Our results indicate that the positive relation between SMBH masses and host galaxy stellar masses already exists at redshift z ≳ 6. The quasars in our sample show a high BH-to-stellar-mass ratio of M BH / M * ∼ 0.15, which is about ∼2 dex higher than local relations. We find that selection effects only contribute partially to the high M BH / M * ratios of high-redshift quasars. This result hints at a possible redshift evolution of the M BH – M * relation.}, number={2}, journal={ASTROPHYSICAL JOURNAL}, author={Yue, Minghao and Eilers, Anna-Christina and Simcoe, Robert A. and Mackenzie, Ruari and Matthee, Jorryt and Kashino, Daichi and Bordoloi, Rongmon and Lilly, Simon J. and Naidu, Rohan P.}, year={2024}, month={May} }
@article{eilers_mackenzie_pizzati_matthee_hennawi_zhang_bordoloi_kashino_lilly_naidu_et al._2024, title={EIGER. VI. The Correlation Function, Host Halo Mass, and Duty Cycle of Luminous Quasars at z ≳ 6}, volume={974}, ISSN={["1538-4357"]}, DOI={10.3847/1538-4357/ad778b}, abstractNote={Abstract We expect luminous ( M 1450 ≲ −26.5) high-redshift quasars to trace the highest-density peaks in the early Universe. Here, we present observations of four z ≳ 6 quasar fields using JWST/NIRCam in the imaging and wide-field slitless spectroscopy mode and report a wide range in the number of detected [O iii ]-emitting galaxies in the quasars’ environments, ranging between a density enhancement of δ ≈ 65 within a 2 cMpc radius—one of the largest protoclusters during the Epoch of Reionization discovered to date—to a density contrast consistent with zero, indicating the presence of a UV-luminous quasar in a region comparable to the average density of the Universe. By measuring the two-point cross-correlation function of quasars and their surrounding galaxies, as well as the galaxy autocorrelation function, we infer a correlation length of quasars at 〈 z 〉 = 6.25 of r 0 QQ = 22.0 − 2.9 + 3.0 cMpc h − 1 , while we obtain a correlation length of the [O iii ]-emitting galaxies of r 0 GG = 4.1 ± 0.3 cMpc h − 1 . By comparing the correlation functions to dark-matter-only simulations we estimate the minimum mass of the quasars’ host dark matter halos to be log 10 ( M halo , min / M ⊙ ) = 12.43 − 0.15 + 0.13 (and log 10 ( M halo , min [ OIII ] / M ⊙ ) = 10.56 − 0.03 + 0.05 for the [O iii ] emitters), indicating that (a) luminous quasars do not necessarily reside within the most overdense regions in the early Universe, and that (b) the UV-luminous duty cycle of quasar activity at these redshifts is f duty ≪ 1. Such short quasar activity timescales challenge our understanding of early supermassive black hole growth and provide evidence for highly dust-obscured growth phases or episodic, radiatively inefficient accretion rates.}, number={2}, journal={ASTROPHYSICAL JOURNAL}, author={Eilers, Anna-Christina and Mackenzie, Ruari and Pizzati, Elia and Matthee, Jorryt and Hennawi, Joseph F. and Zhang, Haowen and Bordoloi, Rongmon and Kashino, Daichi and Lilly, Simon J. and Naidu, Rohan P. and et al.}, year={2024}, month={Oct} }
@article{matthee_naidu_brammer_chisholm_eilers_goulding_greene_kashino_labbe_lilly_et al._2024, title={Little Red Dots: An Abundant Population of Faint Active Galactic Nuclei at z ∼ 5 Revealed by the EIGER and FRESCO JWST Surveys}, volume={963}, ISSN={["1538-4357"]}, DOI={10.3847/1538-4357/ad2345}, abstractNote={Abstract Characterizing the prevalence and properties of faint active galactic nuclei (AGNs) in the early Universe is key for understanding the formation of supermassive black holes (SMBHs) and determining their role in cosmic reionization. We perform a spectroscopic search for broad H α emitters at z ≈ 4–6 using deep JWST/NIRCam imaging and wide field slitless spectroscopy from the EIGER and FRESCO surveys. We identify 20 H α lines at z = 4.2–5.5 that have broad components with line widths from ∼1200–3700 km s −1 , contributing ∼30%–90% of the total line flux. We interpret these broad components as being powered by accretion onto SMBHs with implied masses ∼10 7–8 M ⊙ . In the UV luminosity range M UV,AGN+host = −21 to −18, we measure number densities of ≈10 −5 cMpc −3 . This is an order of magnitude higher than expected from extrapolating quasar UV luminosity functions (LFs). Yet, such AGN are found in only <1% of star-forming galaxies at z ∼ 5. The number density discrepancy is much lower when compared to the broad H α LF. The SMBH mass function agrees with large cosmological simulations. In two objects, we detect complex H α profiles that we tentatively interpret as caused by absorption signatures from dense gas fueling SMBH growth and outflows. We may be witnessing early AGN feedback that will clear dust-free pathways through which more massive blue quasars are seen. We uncover a strong correlation between reddening and the fraction of total galaxy luminosity arising from faint AGN. This implies that early SMBH growth is highly obscured and that faint AGN are only minor contributors to cosmic reionization.}, number={2}, journal={ASTROPHYSICAL JOURNAL}, author={Matthee, Jorryt and Naidu, Rohan P. and Brammer, Gabriel and Chisholm, John and Eilers, Anna-Christina and Goulding, Andy and Greene, Jenny and Kashino, Daichi and Labbe, Ivo and Lilly, Simon J. and et al.}, year={2024}, month={Mar} }
@article{wilde_tchernyshyov_werk_tripp_burchett_prochaska_tejos_lehner_bordoloi_john m. o'meara_et al._2023, title={CGM(2) + CASBaH: The Mass Dependence of H I Ly alpha-Galaxy Clustering and the Extent of the CGM}, volume={948}, ISSN={["1538-4357"]}, DOI={10.3847/1538-4357/acc85b}, abstractNote={Abstract We combine data sets from the CGM 2 and CASBaH surveys to model a transition point, R cross , between circumgalactic and intergalactic media (CGM and IGM, respectively). In total, our data consist of 7244 galaxies at z < 0.5 with precisely measured spectroscopic redshifts, all having impact parameters of 0.01–20 comoving Mpc from 28 QSO sightlines with high-resolution UV spectra that cover H i Ly α . Our best-fitting model is a two-component model that combines a 3D absorber–galaxy cross-correlation function with a simple Gaussian profile at inner radii to represent the CGM. By design, this model gives rise to a determination of R cross as a function of galaxy stellar mass, which can be interpreted as the boundary between the CGM and IGM. For galaxies with 10 8 ≤ M ⋆ / M ⊙ ≤ 10 10.5 , we find that R cross ( M ⋆ ) ≈ 2.0 ± 0.6 R vir . Additionally, we find excellent agreement between R cross ( M ⋆ ) and the theoretically determined splashback radius for galaxies in this mass range. Overall, our results favor models of galaxy evolution at z < 0.5 that distribute T ≈ 10 4 K gas to distances beyond the virial radius.}, number={2}, journal={ASTROPHYSICAL JOURNAL}, author={Wilde, Matthew C. and Tchernyshyov, Kirill and Werk, Jessica K. and Tripp, Todd M. and Burchett, Joseph N. and Prochaska, J. Xavier and Tejos, Nicolas and Lehner, Nicolas and Bordoloi, Rongmon and John M. O'Meara and et al.}, year={2023}, month={May} }
@article{cashman_fox_wakker_ashley_massa_jenkins_krishnarao_benjamin_bordoloi_kim_2023, title={Caught in the Act: A Metal-rich High-velocity Cloud in the Inner Galaxy}, volume={944}, ISSN={["1538-4357"]}, DOI={10.3847/1538-4357/acaaa5}, abstractNote={We characterize the chemical and physical conditions in an outflowing high-velocity cloud in the inner Galaxy. We report a super-solar metallicity of [O/H] = $+0.36\pm0.12$ for the high-velocity cloud at $v_\mathrm{LSR}$ = 125.6 km s$^{-1}$ toward the star HD 156359 ($l$ = 328.$^{\circ}$7, $b$ = $-$14.$^{\circ}$5, $d$ = 9 kpc, $z$ = $-$2.3 kpc). Using archival observations from FUSE, HST STIS, and ESO FEROS we measure high-velocity absorption in H I, O I, C II, N II, Si II, Ca II, Si III, Fe III, C IV, Si IV, N V, and O VI. We measure a low H I column density of log $N$(H I) = $15.54\pm0.05$ in the HVC from multiple unsaturated H I Lyman series lines in the FUSE data. We determine a low dust depletion level in the HVC from the relative strength of silicon, iron, and calcium absorption relative to oxygen, with [Si/O]=$-0.33\pm0.14$, [Fe/O]=$-0.30\pm0.20$, and [Ca/O] =$-0.56\pm0.16$. Analysis of the high-ion absorption using collisional ionization models indicates that the hot plasma is multi-phase, with the C IV and Si IV tracing 10$^{4.9}$ K gas and N V and O VI tracing 10$^{5.4}$ K gas. The cloud's metallicity, dust content, kinematics, and close proximity to the disk are all consistent with a Galactic wind origin. As the HD 156359 line of sight probes the inner Galaxy, the HVC appears to be a young cloud caught in the act of being entrained in a multi-phase Galactic outflow and driven out into the halo.}, number={1}, journal={ASTROPHYSICAL JOURNAL}, author={Cashman, Frances H. H. and Fox, Andrew J. J. and Wakker, Bart P. P. and Ashley, Trisha and Massa, Derck and Jenkins, Edward B. B. and Krishnarao, Dhanesh and Benjamin, Robert A. A. and Bordoloi, Rongmon and Kim, Tae-Sun}, year={2023}, month={Feb} }
@article{kashino_lilly_simcoe_bordoloi_mackenzie_matthee_eilers_2023, title={Compact [CII] emitters around a C iv absorption complex at redshift 5.7}, volume={617}, ISSN={["1476-4687"]}, DOI={10.1038/s41586-023-05901-3}, abstractNote={The physical conditions of the circumgalactic medium are investigated by means of intervening absorption-line systems in the spectrum of background quasi-stellar objects (QSOs) out to the epoch of cosmic reionization1-4. A correlation between the ionization state of the absorbing gas and the nature of the nearby galaxies has been suggested by the sources detected in either Lyα or [C II] 158 μm near to, respectively, highly ionized and neutral absorbers5,6. This is also probably linked to the global changes in the incidence of absorption systems of different types and the process of cosmic reionization7-12. Here we report the detection of two [C II]-emitting galaxies at redshift z ≈ 5.7 that are associated with a complex, high-ionization C IV absorption system. These objects are part of an overdensity of galaxies and have compact sizes (<2.4 kpc) and narrow linewidths (full width at half maximum (FWHM) ≈ 62-64 km s-1). Hydrodynamic simulations predict that similar narrow [C II] emission may arise from the heating of small (≲3 kpc) clumps of cold neutral medium or a compact photodissociation region13,14. The lack of counterparts in the rest-frame ultraviolet (UV) indicates severe obscuration of the sources that are exciting the [C II] emission. These results may suggest a connection between the properties of the [C II] emission, the rare overdensity of galaxies and the unusual high ionization state of the gas in this region.}, number={7960}, journal={NATURE}, author={Kashino, Daichi and Lilly, Simon J. and Simcoe, Robert A. and Bordoloi, Rongmon and Mackenzie, Ruari and Matthee, Jorryt and Eilers, Anna-Christina}, year={2023}, month={May}, pages={261-+} }
@article{shaban_bordoloi_chisholm_rigby_sharma_sharon_tejos_bayliss_barrientos_lopez_et al._2023, title={Dissecting a 30 kpc galactic outflow at z ∼ 1.7}, volume={526}, ISSN={["1365-2966"]}, url={https://doi.org/10.1093/mnras/stad3004}, DOI={10.1093/mnras/stad3004}, abstractNote={ABSTRACT We present the spatially resolved measurements of a cool galactic outflow in the gravitationally lensed galaxy RCS0327 at z ≈ 1.703 using VLT/MUSE IFU observations. We probe the cool outflowing gas, traced by blueshifted Mg ii and Fe ii absorption lines, in 15 distinct regions of the same galaxy in its image-plane. Different physical regions, 5 – 7 kpc apart within the galaxy, drive the outflows at different velocities (Vout ∼ −161 to −240 km s−1), and mass outflow rates ($\dot{M}_{out} \sim 183$ – 527 ${\rm M}_{\odot }\, \mathrm{yr}^{-1}$). The outflow velocities from different regions of the same galaxy vary by 80 km s−1, which is comparable to the variation seen in a large sample of star-burst galaxies in the local universe. Using multiply lensed images of RCS0327, we probe the same star-forming region at different spatial scales (0.5–25 kpc2), we find that outflow velocities vary between ∼ −120 and −242 km s−1, and the mass outflow rates vary between ∼37 and 254 ${\rm M}_{\odot }\, \mathrm{yr}^{-1}$. The outflow momentum flux in this galaxy is ≥ 100% of the momentum flux provided by star formation in individual regions, and outflow energy flux is ≈ 10% of the total energy flux provided by star formation. These estimates suggest that the outflow in RCS0327 is energy driven. This work shows the importance of small scale variations of outflow properties due to the variations of local stellar properties of the host galaxy in the context of galaxy evolution.}, number={4}, journal={MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY}, author={Shaban, Ahmed and Bordoloi, Rongmon and Chisholm, John and Rigby, Jane R. and Sharma, Soniya and Sharon, Keren and Tejos, Nicolas and Bayliss, Matthew B. and Barrientos, L. Felipe and Lopez, Sebastian and et al.}, year={2023}, month={Oct}, pages={6297–6320} }
@article{kashino_lilly_matthee_eilers_mackenzie_bordoloi_simcoe_2023, title={EIGER. I. A Large Sample of [O III]-emitting Galaxies at 5.3 < z < 6.9 and Direct Evidence for Local Reionization by Galaxies}, volume={950}, ISSN={["1538-4357"]}, DOI={10.3847/1538-4357/acc588}, abstractNote={Abstract We present a first sample of 117 [O iii ] λλ 4960, 5008–selected star-forming galaxies at 5.33 < z < 6.93 detected in JWST/NIRCam 3.5 μ m slitless spectroscopy of a 6 .′ 5 × 3 .′ 4 field centered on the hyperluminous quasar SDSS J0100+2802, obtained as part of the Emission-line galaxies and Intergalactic Gas in the Epoch of Reionization (EIGER) survey. Three prominent galaxy overdensities are observed, one of them at the redshift of the quasar. Galaxies are found within 200 pkpc and 105 km s −1 of four known metal absorption-line systems. We focus on the role of the galaxies in ionizing the intergalactic medium (IGM) during the later stages of cosmic reionization and construct the mean Ly α and Ly β transmission as a function of distance from the galaxies. At the lowest redshifts in our study, 5.3 < z < 5.7, the IGM transmission rises monotonically with distance from the galaxies, as seen previously at lower redshifts. In contrast, at 5.7 < z < 6.14, the transmission of both Ly α and Ly β first increases with distance but then peaks at a distance of 5 cMpc before declining. Finally, in the region 6.15 < z < 6.26, where the additional ionizing radiation from the quasar dominates, the monotonic increase in transmission with distance is reestablished. This result is interpreted to represent evidence that the transmission of the IGM at z ∼ 5.9 toward J0100+2802 results from the “local” ionizing radiation of galaxies that dominates over the much-reduced cosmic background.}, number={1}, journal={ASTROPHYSICAL JOURNAL}, author={Kashino, Daichi and Lilly, Simon J. and Matthee, Jorryt and Eilers, Anna-Christina and Mackenzie, Ruari and Bordoloi, Rongmon and Simcoe, Robert A.}, year={2023}, month={Jun} }
@article{matthee_mackenzie_simcoe_kashino_lilly_bordoloi_eilers_2023, title={EIGER. II. First Spectroscopic Characterization of the Young Stars and Ionized Gas Associated with Strong H beta and [O iii] Line Emission in Galaxies at z=5-7 with JWST}, volume={950}, ISSN={["1538-4357"]}, DOI={10.3847/1538-4357/acc846}, abstractNote={We present emission-line measurements and physical interpretations for a sample of 117 [OIII] emitting galaxies at $z=5.33-6.93$, using the first deep JWST/NIRCam wide field slitless spectroscopic observations. Our 9.7-hour integration is centered upon the $z=6.3$ quasar J0100+2802 -- the first of six fields targeted by the EIGER survey -- and covers $\lambda=3-4$ microns. We detect 133 [OIII] doublets, but merge pairs within $\approx$10 kpc and 600 km s$^{-1}$, motivated by their small scale clustering excess. We detect H$\beta$ in 68 and H$\gamma$ emission in two galaxies. The galaxies are characterised by a UV luminosity M$_{\rm UV}\sim-19.6$ ($-17.7$ to $-22.3$), stellar mass ~$10^8$ $(10^{6.8-10.1})$ M$_{\odot}$, H$\beta$ and [OIII] EWs $\approx$ 850 Angstrom (up to 3000 Angstrom), young ages (~100 Myr), a highly excited interstellar medium ([OIII]/H$\beta\approx6$) and low dust attenuations. These high EWs are very rare in the local Universe, but we show they are ubiquitous at $z\sim6$ based on the measured number densities. The stacked spectrum reveals H$\gamma$ and [OIII]$_{4364}$ which shows that the galaxies are typically dust and metal poor (E(B-V)=0.1, 12+log(O/H)=7.4) with a high electron temperature ($2\times10^4$ K) and a production efficiency of ionising photons ($\xi_{\rm ion}=10^{25.3}$ Hz erg$^{-1}$). We further show the existence of a strong mass-metallicity relation. The young highly ionising stellar populations, moderately low metallicities, low dust attenuations and high ionisation state in z~6 galaxies conspire to maximise the [OIII] output from galaxies, yielding an [OIII] luminosity density at z~6 that is significantly higher than at z~2, despite the order of magnitude decline in cosmic star formation. Thus, [OIII] emission-line surveys with JWST prove a highly efficient method to trace the galaxy density in the epoch of reionization.}, number={1}, journal={ASTROPHYSICAL JOURNAL}, author={Matthee, Jorryt and Mackenzie, Ruari and Simcoe, Robert A. and Kashino, Daichi and Lilly, Simon J. and Bordoloi, Rongmon and Eilers, Anna-Christina}, year={2023}, month={Jun} }
@article{eilers_simcoe_yue_mackenzie_matthee_durovcikova_kashino_bordoloi_lilly_2023, title={EIGER. III. JWST/NIRCam Observations of the Ultraluminous High-redshift Quasar J0100+2802}, volume={950}, ISSN={["1538-4357"]}, DOI={10.3847/1538-4357/acd776}, abstractNote={We present the first rest-frame optical spectrum of a high-redshift quasar observed with JWST/NIRCam in Wide Field Slitless (WFSS) mode. The observed quasar, J0100+2802, is the most luminous quasar known at $z>6$. We measure the mass of the central supermassive black hole (SMBH) by means of the rest-frame optical H$\beta$ emission line, and find consistent mass measurements of the quasar's SMBH of $M_\bullet\approx10^{10}\,M_\odot$ when compared to the estimates based on the properties of rest-frame UV emission lines CIV and MgII, which are accessible from ground-based observatories. To this end, we also present a newly reduced rest-frame UV spectrum of the quasar observed with X-Shooter/VLT and FIRE/Magellan for a total of 16.8 hours. We readdress the question whether this ultra-luminous quasar could be effected by strong gravitational lensing making use of the diffraction limited NIRCam images in three different wide band filters (F115W, F200W, F356W), which improves the achieved spatial resolution compared to previous images taken with the Hubble Space Telescope by a factor of two. We do not find any evidence for a foreground deflecting galaxy, nor for multiple images of the quasar, and determine the probability for magnification due to strong gravitational lensing with image separations below the diffraction limit of $\Delta\theta\lesssim 0.05''$ to be $\lesssim 2.2\times 10^{-3}$. Our observations therefore confirm that this quasar hosts a ten billion solar mass black hole less than $1$ Gyr after the Big Bang, which is challenging to explain with current black hole formation models.}, number={1}, journal={ASTROPHYSICAL JOURNAL}, author={Eilers, Anna-Christina and Simcoe, Robert A. and Yue, Minghao and Mackenzie, Ruari and Matthee, Jorryt and Durovcikova, Dominika and Kashino, Daichi and Bordoloi, Rongmon and Lilly, Simon J.}, year={2023}, month={Jun} }
@article{berg_lehner_howk_john m. o'meara_schaye_straka_cooksey_tripp_prochaska_oppenheimer_et al._2023, title={The Bimodal Absorption System Imaging Campaign (BASIC). I. A Dual Population of Low-metallicity Absorbers at z < 1}, volume={944}, ISSN={["1538-4357"]}, DOI={10.3847/1538-4357/acb047}, abstractNote={The bimodal absorption system imaging campaign (BASIC) aims to characterize the galaxy environments of a sample of 36 HI-selected partial Lyman limit systems (pLLSs) and Lyman limit systems (LLSs) in 23 QSO fields at $z \lesssim 1$. These pLLSs/LLSs provide a unique sample of absorbers with unbiased and well-constrained metallicities, allowing us to explore the origins of metal-rich and low-metallicity circumgalactic medium (CGM) at $z<1$. Here we present Keck/KCWI and VLT/MUSE observations of 11 of these QSO fields (19 pLLSs) that we combine with HST/ACS imaging to identify and characterize the absorber-associated galaxies. We find 23 unique absorber-associated galaxies, with an average of one associated galaxy per absorber. For seven absorbers, all with $<10\%$ solar metallicities, we find no associated galaxies with $\log M_\star \gtrsim 9.0$ within $\rho/R_{vir}$ and $|\Delta v|/v_{esc} \le$ 1.5 with respect to the absorber. We do not find any strong correlations between the metallicities or HI column densities of the gas and most of the galaxy properties, except for the stellar mass of the galaxies: the low-metallicity ([X/H] $\le -1.4$) systems have a probability of $0.39^{+0.16}_{-0.15}$ for having a host galaxy with $\log M_\star \ge 9.0$ within $\rho/R_{vir} \le 1.5$, while the higher metallicity absorbers have a probability of $0.78^{+0.10}_{-0.13}$. This implies metal-enriched pLLSs/LLSs at $z<1$ are typically associated with the CGM of galaxies with $\log M_\star > 9.0$, whereas low-metallicity pLLSs/LLSs are found in more diverse locations, with one population arising in the CGM of galaxies and another more broadly distributed in overdense regions of the universe. Using absorbers not associated with galaxies, we estimate the unweighted geometric mean metallicity of the intergalactic medium to be [X/H] $\lesssim -2.1$ at $z<1$, which is lower than previously estimated.}, number={1}, journal={ASTROPHYSICAL JOURNAL}, author={Berg, Michelle A. and Lehner, Nicolas and Howk, J. Christopher and John M. O'Meara and Schaye, Joop and Straka, Lorrie A. and Cooksey, Kathy L. and Tripp, Todd M. and Prochaska, J. Xavier and Oppenheimer, Benjamin D. and et al.}, year={2023}, month={Feb} }
@article{tchernyshyov_werk_wilde_prochaska_tripp_burchett_bordoloi_howk_lehner_john m. o'meara_et al._2023, title={The CGM(2) Survey: Quenching and the Transformation of the Circumgalactic Medium}, volume={949}, ISSN={["1538-4357"]}, DOI={10.3847/1538-4357/acc86a}, abstractNote={Abstract This study addresses how the incidence rate of strong O vi absorbers in a galaxy’s circumgalactic medium (CGM) depends on galaxy mass and, independently, on the amount of star formation in the galaxy. We use Hubble Space Telescope/Cosmic Origins Spectrograph absorption spectroscopy of quasars to measure O vi absorption within 400 projected kpc and 300 km s −1 of 52 galaxies with M * ∼ 3 × 10 10 M ⊙ . The galaxies have redshifts 0.12 < z < 0.6, stellar masses 10 10.1 M ⊙ < M * < 10 10.9 M ⊙ , and spectroscopic classifications as star-forming or passive. We compare the incidence rates of high column density O vi absorption ( N O VI ≥ 10 14.3 cm −2 ) near star-forming and passive galaxies in two narrow ranges of stellar mass and, separately, in a matched range of halo mass. In all three mass ranges, the O vi covering fraction within 150 kpc is higher around star-forming galaxies than around passive galaxies with greater than 3 σ -equivalent statistical significance. On average, the CGM of star-forming galaxies with M * ∼ 3 × 10 10 M ⊙ contains more O vi than the CGM of passive galaxies with the same mass. This difference is evidence for a CGM transformation that happens together with galaxy quenching and is not driven primarily by halo mass.}, number={2}, journal={ASTROPHYSICAL JOURNAL}, author={Tchernyshyov, Kirill and Werk, Jessica K. and Wilde, Matthew C. and Prochaska, J. Xavier and Tripp, Todd M. and Burchett, Joseph N. and Bordoloi, Rongmon and Howk, J. Christopher and Lehner, Nicolas and John M. O'Meara and et al.}, year={2023}, month={Jun} }
@article{soto_ashley_fox_bordoloi_2023, title={The Signature of the Northern Galactic Center Region in Low-velocity UV Absorption}, volume={954}, ISSN={["1538-4357"]}, DOI={10.3847/1538-4357/ace597}, abstractNote={Abstract The Galactic Center (GC) is surrounded by plasma lobes that extend up to ∼14 kpc above and below the plane. Until now, UV absorption studies of these lobes have only focused on high-velocity components (∣ v LSR ∣ > 100 km s −1 ) because low- and intermediate-velocity (LIV) components (∣ v LSR ∣ < 100 km s −1 ) are blended with foreground interstellar medium. To overcome this difficulty, we present a differential experiment to compare the LIV absorption between different structures within the GC region, including the Fermi Bubbles (FBs; seen in gamma rays), the eROSITA Bubbles (eBs; seen in X-rays), and the Loop I North Polar Spur (LNPS) association, an X-ray and radio feature within the northern eB. We use far-UV spectra from Hubble Space Telescope to measure LIV Si iv absorption in 61 active galactic nuclei sight lines, of which 21 pass through the FBs, 53 pass through the eBs, and 18 pass through the LNPS. We also compare our measurements to those in the literature from sight lines covering the disk–halo interface and circumgalactic medium (CGM). We find that the FBs and eBs have enhancements in measured columns of 0.22–0.29 dex in log. We also remove the contribution of a modeled disk and CGM component from the measured Si iv columns and find that the northern eB still retains a Si iv enhancement of 0.62 dex in log. A similar enhancement is not seen in the southern eB. Since a notable difference between the northern and southern eBs is the presence of the LNPS association in the nothern bubble, the northern eB enhancement may be caused by the LNPS.}, number={1}, journal={ASTROPHYSICAL JOURNAL}, author={Soto, Christian and Ashley, Trisha and Fox, Andrew J. and Bordoloi, Rongmon}, year={2023}, month={Sep} }
@article{shaban_bordoloi_chisholm_sharma_sharon_rigby_gladders_bayliss_barrientos_lopez_et al._2022, title={A 30 kpc Spatially Extended Clumpy and Asymmetric Galactic Outflow at z similar to 1.7}, volume={936}, ISSN={["1538-4357"]}, url={https://doi.org/10.3847/1538-4357/ac7c65}, DOI={10.3847/1538-4357/ac7c65}, abstractNote={We image the spatial extent of a cool galactic outflow with fine structure Fe II$^*$ emission and resonant Mg II emission in a gravitationally lensed star-forming galaxy at $z = 1.70347$. The Fe II$^*$ and Mg II (continuum-subtracted) emissions span out to radial distances of $\sim$14.33 kpc and 26.5 kpc, respectively, with maximum spatial extents of $\sim$21 kpc for Fe II$^*$ emission and $\sim$30 kpc for Mg II emission. Mg II residual emission is patchy and covers a total area of $\sim$184 kpc$^2$, constraining the minimum area covered by the outflowing gas to be $\sim$13% of the total area. Mg II emission is asymmetric and shows $\sim$21% more extended emission along the declination direction. We constrain the covering fractions of the Fe II$^*$ and Mg II emission as a function of radial distance and characterize them with a power law model. The Mg II 2803 emission line shows two kinematically distinct emission components, and may correspond to two distinct shells of outflowing gas with a velocity separation of $\Delta v \sim$ 400 km/s. By using multiple images with different magnifications of the galaxy in the image plane, we trace the Fe II$^*$, Mg II emissions around three individual star-forming regions. In all cases, both the Fe II$^*$ and Mg II emissions are more spatially extended compared to the star forming regions traced by the [O II] emission. These findings provide robust constraints on the spatial extent of the outflowing gas, and combined with outflow velocity and column density measurements will give stringent constraints on mass outflow rates of the galaxy.}, number={1}, journal={ASTROPHYSICAL JOURNAL}, author={Shaban, Ahmed and Bordoloi, Rongmon and Chisholm, John and Sharma, Soniya and Sharon, Keren and Rigby, Jane R. and Gladders, Michael G. and Bayliss, Matthew B. and Barrientos, L. Felipe and Lopez, Sebastian and et al.}, year={2022}, month={Sep} }
@article{xu_heckman_henry_berg_chisholm_james_martin_stark_aloisi_amorin_et al._2022, title={CLASSY III. The Properties of Starburst-driven Warm Ionized Outflows*}, volume={933}, ISSN={["1538-4357"]}, DOI={10.3847/1538-4357/ac6d56}, abstractNote={Abstract We report the results of analyses of galactic outflows in a sample of 45 low-redshift starburst galaxies in the COS Legacy Archive Spectroscopic SurveY (CLASSY), augmented by five additional similar starbursts with Cosmic Origins Spectrograph (COS) data. The outflows are traced by blueshifted absorption lines of metals spanning a wide range of ionization potential. The high quality and broad spectral coverage of CLASSY data enable us to disentangle the absorption due to the static interstellar medium (ISM) from that due to outflows. We further use different line multiplets and doublets to determine the covering fraction, column density, and ionization state as a function of velocity for each outflow. We measure the outflow’s mean velocity and velocity width, and find that both correlate in a highly significant way with the star formation rate, galaxy mass, and circular velocity over ranges of four orders of magnitude for the first two properties. We also estimate outflow rates of metals, mass, momentum, and kinetic energy. We find that, at most, only about 20% of silicon created and ejected by supernovae in the starburst is carried out in the warm phase we observe. The outflows’ mass-loading factor increases steeply and inversely with both circular and outflow velocity (log–log slope ∼−1.6), and reaches ∼10 for dwarf galaxies. We find that the outflows typically carry about 10%–100% of the momentum injected by massive stars and about 1%–20% of the kinetic energy. We show that these results place interesting constraints on, and new insights into, models and simulations of galactic winds.}, number={2}, journal={ASTROPHYSICAL JOURNAL}, author={Xu, Xinfeng and Heckman, Timothy and Henry, Alaina and Berg, Danielle A. and Chisholm, John and James, Bethan L. and Martin, Crystal L. and Stark, Daniel P. and Aloisi, Alessandra and Amorin, Ricardo O. and et al.}, year={2022}, month={Jul} }
@article{james_berg_king_sahnow_mingozzi_chisholm_heckman_martin_stark_aloisi_et al._2022, title={CLASSY. II. A Technical Overview of the COS Legacy Archive Spectroscopic Survey*}, volume={262}, ISSN={["1538-4365"]}, DOI={10.3847/1538-4365/ac8008}, abstractNote={Abstract The COS Legacy Archive Spectroscopic SurveY (CLASSY) is designed to provide the community with a spectral atlas of 45 nearby star-forming galaxies that were chosen to cover similar properties to those seen at high z ( z > 6). The prime high-level science product of CLASSY is accurately coadded UV spectra, ranging from ∼1000 to 2000 Å, derived from a combination of archival and new data obtained with HST’s Cosmic Origins Spectrograph (COS). This paper details the multistage technical processes of creating this prime data product and the methodologies involved in extracting, reducing, aligning, and coadding far-ultraviolet and near-ultraviolet (NUV) spectra. We provide guidelines on how to successfully utilize COS observations of extended sources, despite COS being optimized for point sources, and best-practice recommendations for the coaddition of UV spectra in general. Moreover, we discuss the effects of our reduction and coaddition techniques in the scientific application of the CLASSY data. In particular, we find that accurately accounting for flux calibration offsets can affect the derived properties of the stellar populations, while customized extractions of NUV spectra for extended sources are essential for correctly diagnosing the metallicity of galaxies via C iii ] nebular emission. Despite changes in spectral resolution of up to ∼25% between individual data sets (due to changes in the COS line-spread function), no adverse affects were observed on the difference in velocity width and outflow velocities of isolated absorption lines when measured in the final combined data products, owing in part to our signal-to-noise regime of S/N < 20.}, number={2}, journal={ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES}, author={James, Bethan L. and Berg, Danielle A. and King, Teagan and Sahnow, David J. and Mingozzi, Matilde and Chisholm, John and Heckman, Timothy and Martin, Crystal L. and Stark, Dan P. and Aloisi, Alessandra and et al.}, year={2022}, month={Oct} }
@article{ashley_fox_cashman_lockman_bordoloi_jenkins_wakker_karim_2022, title={Diverse metallicities of Fermi bubble clouds indicate dual origins in the disk and halo}, volume={7}, ISSN={["2397-3366"]}, DOI={10.1038/s41550-022-01720-0}, abstractNote={The Galactic Centre is surrounded by two giant plasma lobes known as the Fermi bubbles, extending ~10 kpc both above and below the Galactic plane. Spectroscopic observations of Fermi bubble directions at radio, ultraviolet and optical wavelengths have detected multi-phase gas clouds thought to be embedded within the bubbles, referred to as Fermi bubble high-velocity clouds (FB HVCs). Although these clouds have kinematics that can be modelled by a biconical nuclear wind launched from the Galactic Centre, their exact origin is unknown because there has so far been little information on their heavy metal abundances (metallicities). Here we show that FB HVCs have a wide range of metallicities from <20% of solar to ~320% of solar, based on a metallicity survey of twelve FB HVCs. These metallicities challenge the previously accepted tenet that all FB HVCs are launched from the Galactic Centre into the Fermi bubbles with solar or supersolar metallicities. Instead, we suggest that FB HVCs originate in both the Milky Way’s disk and halo. As such, some of these clouds may characterize the circumgalactic medium that the Fermi bubbles expand into, rather than material carried outwards by the nuclear wind, changing the canonical picture of FB HVCs. More broadly, these results reveal that nuclear outflows from spiral galaxies can operate by sweeping up gas in their haloes while simultaneously removing gas from their disks. A metallicity survey of Fermi bubble clouds reveals a wide range of metallicities, challenging the theory that all of these clouds launch from the Milky Way’s disk and instead suggesting that they originate in both the disk and halo.}, journal={NATURE ASTRONOMY}, author={Ashley, Trisha and Fox, Andrew J. and Cashman, Frances H. and Lockman, Felix J. and Bordoloi, Rongmon and Jenkins, Edward B. and Wakker, Bart P. and Karim, Tanveer}, year={2022}, month={Jul} }
@article{bordoloi_john m. o'meara_sharon_rigby_cooke_shaban_matuszewski_rizzi_doppmann_martin_et al._2022, title={Resolving the H i in damped Lyman alpha systems that power star formation}, volume={5}, ISSN={["1476-4687"]}, url={https://doi.org/10.1038/s41586-022-04616-1}, DOI={10.1038/s41586-022-04616-1}, abstractNote={Reservoirs of dense atomic gas (primarily hydrogen), contain approximately 90 percent of the neutral gas at a redshift of 3, and contribute to 2-3 percent of the total baryons in the Universe. These damped Lyman-${\alpha}$ systems (so called because they absorb Lyman-${\alpha}$ photons from within and from background sources) have been studied for decades, but only through absorption lines present in the spectra of background quasars and gamma-ray bursts. Such pencil beams do not constrain the physical extent of the systems. Here, we report integral-field spectroscopy of a bright, gravitationally lensed galaxy at a redshift of 2.7 with two foreground damped Lyman-${\alpha}$ systems. These systems are $>$ 238 $kpc^2$ in extent, with column densities of neutral hydrogen varying by more than an order of magnitude on $<$ 3 kpc-scales. The mean column densities are $10^{20.46}$ - $10^{20.84} cm^{-2}$ and the total masses are $> 5.5 \times 10^{8}$ - $1.4 \times 10^{9} M_{\odot}$, showing that they contain the necessary fuel for the next generation of star formation, consistent with relatively massive, low-luminosity primeval galaxies at redshifts $>$ 2.}, journal={NATURE}, publisher={Springer Science and Business Media LLC}, author={Bordoloi, Rongmon and John M. O'Meara and Sharon, Keren and Rigby, Jane R. and Cooke, Jeff and Shaban, Ahmed and Matuszewski, Mateusz and Rizzi, Luca and Doppmann, Greg and Martin, D. Christopher and et al.}, year={2022}, month={May} }
@article{clark_bordoloi_fox_2022, title={Spatially resolved gas flows around the Milky Way}, volume={512}, ISSN={["1365-2966"]}, url={http://dx.doi.org/10.1093/mnras/stac504}, DOI={10.1093/mnras/stac504}, abstractNote={We present spatially resolved measurements of cool gas flowing into and out of the Milky Way (MW), using archival ultraviolet spectra of background quasars from the Hubble Space Telescope/Cosmic Origins Spectrograph. We co-add spectra of different background sources at close projected angular separation on the sky. This novel stacking technique dramatically increases the signal-to-noise ratio of the spectra, allowing detection of low column density gas (down to $EW$ > 2 mA). We identify absorption as inflowing or outflowing, by using blue/redshifted high velocity cloud (HVC) absorption components in the Galactocentric rest frame, respectively. The mass surface densities of inflowing and outflowing gas both vary by more than an order of magnitude across the sky, with mean values of $\langle Σ_{in}\rangle \gtrsim 10^{4.6\pm0.1}$ $M_{\odot}\,\mathrm{kpc}^{-2}$ for inflowing gas and $\langle Σ_{out}\rangle \gtrsim 10^{3.5\pm 0.1}$ $M_{\odot}\,\mathrm{kpc}^{-2}$ for outflowing gas, respectively. The mass flow rate surface densities (mass flow rates per unit area) also show large variation across the sky with $\langle \dotΣ(d)_{in}\rangle \gtrsim (10^{-3.6\pm0.1})(d/12 \mathrm{kpc})^{-1} M_{\odot}\,\mathrm{kpc}^{-2} \mathrm{yr}^{-1}$ for inflowing and $\langle \dotΣ(d)_{out}\rangle \gtrsim (10^{-4.8\pm0.1})(d/12\,\mathrm{kpc})^{-1} M_{\odot}\,\mathrm{kpc}^{-2}\,\mathrm{yr}^{-1}$ for outflowing gas, respectively. The regions with highest surface mass density of inflowing gas are clustered at smaller angular scales ($θ< 40^\circ$). This indicates that most of the mass in inflowing gas is confined to small, well-defined structures, whereas the distribution of outflowing gas is spread more uniformly throughout the sky. Our study confirms that the MW is predominantly accreting gas, but is also losing a non-negligible mass of gas via outflow.}, number={1}, journal={MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY}, publisher={Oxford University Press (OUP)}, author={Clark, Sean and Bordoloi, Rongmon and Fox, Andrew J.}, year={2022}, month={Mar}, pages={811–836} }
@article{tchernyshyov_werk_wilde_prochaska_tripp_burchett_bordoloi_howk_lehner_john m. o'meara_et al._2022, title={The CGM(2) Survey: Circumgalactic O vi from Dwarf to Massive Star-forming Galaxies}, volume={927}, ISSN={["1538-4357"]}, DOI={10.3847/1538-4357/ac450c}, abstractNote={We combine 126 new galaxy-O VI absorber pairs from the CGM$^2$ survey with 123 pairs drawn from the literature to examine the simultaneous dependence of the column density of O VI absorbers ($N_{\rm O VI}$) on galaxy stellar mass, star formation rate, and impact parameter. The combined sample consists of 249 galaxy-O VI absorber pairs covering $z=0$-$0.6$, with host galaxy stellar masses $M^*=10^{7.8}$-$10^{11.2}$ $M_\odot$ and galaxy-absorber impact parameters $R_\perp=0$-$400$ proper kiloparsecs. In this work, we focus on the variation of $N_{\rm O VI}$ with galaxy mass and impact parameter among the star-forming galaxies in the sample. We find that the average $N_{\rm O VI}$ within one virial radius of a star-forming galaxy is greatest for star-forming galaxies with $M^*=10^{9.2}$-$10^{10}$ $M_\odot$. Star-forming galaxies with $M^*$ between $10^{8}$ and $10^{11.2}$ $M_\odot$ can explain most O VI systems with column densities greater than 10$^{13.5}$ cm$^{-2}$. 60% of the O VI mass associated with a star-forming galaxy is found within one virial radius and 35% is found between one and two virial radii. In general, we find that some departure from hydrostatic equilibrium in the CGM is necessary to reproduce the observed O VI amount, galaxy mass dependence, and extent. Our measurements serve as a test set for CGM models over a broad range of host galaxy masses.}, number={2}, journal={ASTROPHYSICAL JOURNAL}, author={Tchernyshyov, Kirill and Werk, Jessica K. and Wilde, Matthew C. and Prochaska, J. Xavier and Tripp, Todd M. and Burchett, Joseph N. and Bordoloi, Rongmon and Howk, J. Christopher and Lehner, Nicolas and John M. O'Meara and et al.}, year={2022}, month={Mar} }
@article{berg_james_king_mcdonald_chen_chisholm_heckman_martin_stark_aloisi_et al._2022, title={The COS Legacy Archive Spectroscopy Survey (CLASSY) Treasury Atlas}, volume={261}, ISSN={["1538-4365"]}, DOI={10.3847/1538-4365/ac6c03}, abstractNote={Far-ultraviolet (FUV; ~1200-2000 angstroms) spectra are fundamental to our understanding of star-forming galaxies, providing a unique window on massive stellar populations, chemical evolution, feedback processes, and reionization. The launch of JWST will soon usher in a new era, pushing the UV spectroscopic frontier to higher redshifts than ever before, however, its success hinges on a comprehensive understanding of the massive star populations and gas conditions that power the observed UV spectral features. This requires a level of detail that is only possible with a combination of ample wavelength coverage, signal-to-noise, spectral-resolution, and sample diversity that has not yet been achieved by any FUV spectral database. We present the COS Legacy Spectroscopic SurveY (CLASSY) treasury and its first high level science product, the CLASSY atlas. CLASSY builds on the HST archive to construct the first high-quality (S/N_1500 >~ 5/resel), high-resolution (R~15,000) FUV spectral database of 45 nearby (0.002 < z < 0.182) star-forming galaxies. The CLASSY atlas, available to the public via the CLASSY website, is the result of optimally extracting and coadding 170 archival+new spectra from 312 orbits of HST observations. The CLASSY sample covers a broad range of properties including stellar mass (6.2 < logM_star(M_sol) < 10.1), star formation rate (-2.0 < log SFR (M_sol/yr) < +1.6), direct gas-phase metallicity (7.0 < 12+log(O/H) < 8.8), ionization (0.5 < O_32 < 38.0), reddening (0.02 < E(B-V < 0.67), and nebular density (10 < n_e (cm^-3) < 1120). CLASSY is biased to UV-bright star-forming galaxies, resulting in a sample that is consistent with z~0 mass-metallicity relationship, but is offset to higher SFRs by roughly 2 dex, similar to z >~2 galaxies. This unique set of properties makes the CLASSY atlas the benchmark training set for star-forming galaxies across cosmic time.}, number={2}, journal={ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES}, author={Berg, Danielle A. and James, Bethan L. and King, Teagan and McDonald, Meaghan and Chen, Zuyi and Chisholm, John and Heckman, Timothy and Martin, Crystal L. and Stark, Dan P. and Aloisi, Alessandra and et al.}, year={2022}, month={Aug} }
@article{mainali_rigby_chisholm_bayliss_bordoloi_gladders_rivera-thorsen_dahle_sharon_florian_et al._2022, title={The Connection Between Galactic Outflows and the Escape of Ionizing Photons}, volume={940}, ISSN={["1538-4357"]}, DOI={10.3847/1538-4357/ac9cd6}, abstractNote={We analyze spectra of a gravitationally lensed galaxy, known as the Sunburst Arc, that is leaking ionizing photons, also known as the Lyman continuum (LyC). Magnification from gravitational lensing permits the galaxy to be spatially resolved into one region that leaks ionizing photons, and several that do not. Rest-frame ultraviolet and optical spectra from Magellan target ten different regions along the lensed Arc, including six multiple images of the LyC leaking region, as well as four regions that do not show LyC emission. The rest-frame optical spectra of the ionizing photon emitting regions reveal a blue-shifted ($\Delta V$=27 km s$^{-1}$) broad emission component (FWHM=327 km s$^{-1}$) comprising 55% of the total [OIII] line flux, in addition to a narrow component (FWHM = 112 km s$^{-1}$), suggesting the presence of strong highly ionized gas outflows. This is consistent with the high-velocity ionized outflow inferred from the rest-frame UV spectra. In contrast, the broad emission component is less prominent in the non-leaking regions, comprising $\sim$26% of total [OIII] line flux. The high ionization absorption lines are prominent in both leaker and non-leaker but low ionization absorption lines are very weak in the leaker, suggesting that the line of sight gas is highly ionized in the leaker. Analyses of stellar wind features reveal that the stellar population of the LyC leaking regions is considerably younger ($\sim$3 Myr) than the non-leaking regions ($\sim$12 Myr), highlighting that stellar feedback from young stars may play an important role in ionizing photon escape.}, number={2}, journal={ASTROPHYSICAL JOURNAL}, author={Mainali, Ramesh and Rigby, Jane R. and Chisholm, John and Bayliss, Matthew and Bordoloi, Rongmon and Gladders, Michael D. and Rivera-Thorsen, T. Emil and Dahle, Hakon and Sharon, Keren and Florian, Michael and et al.}, year={2022}, month={Dec} }
@article{a 39 kpc spatially extended clumpy and asymmetric galactic outflow imaged with mg ii emission_2021, journal={Monthly Notices of the Royal Astronomical Society}, year={2021}, month={Sep} }
@article{a near-infrared search for molecular gas in the fermi bubbles_2021, DOI={10.3847/2515-5172/ac205d}, abstractNote={We present Gemini/NIFS near-IR integral field spectroscopy of the fields-of-view around two AGNs behind the Fermi Bubbles (PDS 456 and 1H1613-097) to search for molecular gas in the Milky Way's nuclear wind. These two AGN sightlines were selected by the presence of high-velocity neutral and ionized gas seen in UV absorption. We do not detect any extended emission from the H2 ro-vibrational S(0) and S(1) lines at 2.224 and 2.122 microns in either direction. For the S(1) line, the 3-sigma surface brightness limits derived from spectra extracted across the full 3x3 arcsecond NIFS field-of-view are 2.4e-17 erg/cm2/s/A/arcsec2 for PDS 456 and and 4.9e-18 erg/cm2/s/A/arcsec2 for 1H1613-097. Given these non-detections, we conclude that CO emission-line studies and H2 UV absorption-line studies are more promising approaches for characterizing the molecular gas in the Fermi Bubbles.}, journal={RNAAS, 5, 198 (2021)}, year={2021}, month={Aug} }
@article{liu_bordoloi_2021, title={A deep learning approach to quasar continuum prediction}, volume={502}, ISSN={["1365-2966"]}, DOI={10.1093/mnras/stab177}, abstractNote={We present a novel intelligent quasar continuum neural network (iQNet), predicting the intrinsic continuum of any quasar in the rest-frame wavelength range 1020 Angstroms $\leq \lambda \leq$ 1600 Angstroms. We train this network using high-resolution Hubble Space Telescope/Cosmic Origin Spectrograph ultraviolet quasar spectra at low redshift ($z \sim 0.2$) from the Hubble Spectroscopic Legacy Archive, and apply it to predict quasar continua from different astronomical surveys. We utilize the HSLA quasar spectra that are well-defined in the rest-frame wavelength range [1020, 1600] Angstroms with an overall median signal-to-noise ratio of at least five. The iQNet achieves a median AFFE of 2.24% on the training quasar spectra, and 4.17% on the testing quasar spectra. We apply iQNet and predict the continua of $\sim$3200 SDSS-DR16 quasar spectra at higher redshift ($2< z \leq 5$) and measure the redshift evolution of mean transmitted flux ($< F >$) in the Ly-$\alpha$ forest region. We measure a gradual evolution of $< F >$ with redshift, which we characterize as a power-law fit to the effective optical depth of the Ly-$\alpha$ forest. Our measurements are broadly consistent with other estimates of $$ in the literature, but provide a more accurate measurement as we are directly measuring the quasar continuum where there is minimum contamination from the Ly-$\alpha$ forest. This work proves that the deep learning iQNet model can predict the quasar continuum with high accuracy and shows the viability of such methods for quasar continuum prediction.}, number={3}, journal={MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY}, author={Liu, Bin and Bordoloi, Rongmon}, year={2021}, month={Apr}, pages={3510–3532} }
@article{wilde_werk_burchett_prochaska_tchernyshyov_tripp_tejos_lehner_bordoloi_john m. o'meara_et al._2021, title={CGM(2) I: The Extent of the Circumgalactic Medium Traced by Neutral Hydrogen}, volume={912}, ISSN={["1538-4357"]}, DOI={10.3847/1538-4357/abea14}, abstractNote={Abstract We present initial results from the Cosmic Origins Spectrograph (COS) and Gemini Mapping the Circumgalactic Medium (CGMCGM ≡ CGM 2 ) survey. The CGM 2 survey consists of 1689 galaxies, all with high-quality Gemini-GMOS spectra, within 1 Mpc of 22 z ≲ 1 quasars, all with a signal-to-noise ratio of ∼10 Hubble Space Telescope/COS G130M+G160M spectra. For 572 of these galaxies with stellar masses 10 7 M ⊙ < M ⋆ < 10 11 M ⊙ and z ≲ 0.5, we show that the H i covering fraction above a threshold of N HI > 10 14 cm −2 is ≳0.5 within 1.5 virial radii ( R vir ∼ R 200m ). We examine the H i kinematics and find that the majority of absorption lies within ±250 km s −1 of the galaxy systemic velocity. We examine H i covering fractions over a range of impact parameters to infer a characteristic size of the CGM, , as a function of galaxy mass. is the impact parameter at which the probability of observing an absorber with N HI >10 14 cm −2 is >50%. In this framework, the radial extent of the CGM of M ⋆ > 10 9.9 M ⊙ galaxies is kpc or . Intermediate-mass galaxies with 10 9.2 < M ⋆ / M ⊙ < 10 9.9 have an extent of kpc or . Low-mass galaxies, M ⋆ < 10 9.2 M ⊙ , show a smaller physical scale of kpc and extend to . Our analysis suggests that using R vir as a proxy for the characteristic radius of the CGM likely underestimates its extent.}, number={1}, journal={ASTROPHYSICAL JOURNAL}, author={Wilde, Matthew C. and Werk, Jessica K. and Burchett, Joseph N. and Prochaska, J. Xavier and Tchernyshyov, Kirill and Tripp, Todd M. and Tejos, Nicolas and Lehner, Nicolas and Bordoloi, Rongmon and John M. O'Meara and et al.}, year={2021}, month={May} }
@article{detection of a multiphase intragroup medium: results from the cos-igrm survey_2021, DOI={10.17909/t9-wqg9-9043}, abstractNote={We present the results of the COS Intragroup Medium (COS-IGrM) Survey that used the Cosmic Origins Spectrograph on the Hubble Space Telescope to observe a sample of 18 UV bright quasars, each probing the intragroup medium (IGrM) of a galaxy group. We detect Ly$\alpha$, C II, N V, Si II, Si III, and O VI in multiple sightlines. The highest ionization species detected in our data is O VI, which was detected in 8 out of 18 quasar sightlines. The wide range of ionization states observed provide evidence that the IGrM is patchy and multiphase. We find that the O VI detections generally align with radiatively cooling gas between $10^{5.8}$ and $10^6$ K. The lack of O VI detections in 10 of the 18 groups illustrates that O VI may not be the ideal tracer of the volume filling component of the IGrM. Instead, it either exists at trace levels in a hot IGrM or is generated in the boundary between the hotter IGrM and cooler gas.}, journal={The Astrophysical Journal}, year={2021}, month={Sep} }
@article{mccabe_borthakur_heckman_tumlinson_bordoloi_dave_2021, title={Detection of a Multiphase Intragroup Medium: Results from the COS-IGrM Survey}, volume={923}, ISSN={["1538-4357"]}, DOI={10.3847/1538-4357/ac283c}, abstractNote={We present the results of the COS Intragroup Medium (COS-IGrM) Survey that used the Cosmic Origins Spectrograph on the Hubble Space Telescope to observe a sample of 18 UV bright quasars, each probing the intragroup medium (IGrM) of a galaxy group. We detect Ly$\alpha$, C II, N V, Si II, Si III, and O VI in multiple sightlines. The highest ionization species detected in our data is O VI, which was detected in 8 out of 18 quasar sightlines. The wide range of ionization states observed provide evidence that the IGrM is patchy and multiphase. We find that the O VI detections generally align with radiatively cooling gas between $10^{5.8}$ and $10^6$ K. The lack of O VI detections in 10 of the 18 groups illustrates that O VI may not be the ideal tracer of the volume filling component of the IGrM. Instead, it either exists at trace levels in a hot IGrM or is generated in the boundary between the hotter IGrM and cooler gas.}, number={2}, journal={ASTROPHYSICAL JOURNAL}, author={McCabe, Tyler and Borthakur, Sanchayeeta and Heckman, Timothy and Tumlinson, Jason and Bordoloi, Rongmon and Dave, Romeel}, year={2021}, month={Dec} }
@article{cashman_fox_savage_wakker_krishnarao_benjamin_richter_ashley_jenkins_lockman_et al._2021, title={Molecular Gas within the Milky Way's Nuclear Wind}, volume={923}, ISSN={["2041-8213"]}, DOI={10.3847/2041-8213/ac3cbc}, abstractNote={We report the first direct detection of molecular hydrogen associated with the Galactic nuclear wind. The Far-Ultraviolet Spectroscopic Explorer spectrum of LS 4825, a B1 Ib-II star at $l,b$ = 1.67$^{\circ}$,$-$6.63$^{\circ}$ lying $d$ = 9.9$^{+1.4}_{-0.8}$ kpc from the Sun, $\sim$1 kpc below the Galactic plane near the Galactic Center, shows two high-velocity H$_2$ components at $v_\mathrm{LSR}$ = $-79$ and $-108$ km s$^{-1}$. In contrast, the FUSE spectrum of the nearby ($\sim$0.6$^{\circ}$ away) foreground star HD 167402 at $d$=4.9$^{+0.8}_{-0.7}$ kpc reveals no H$_2$ absorption at these velocities. Over 60 lines of H$_2$ from rotational levels $J$ = 0 to 5 are identified in the high-velocity clouds. For the $v_\mathrm{LSR}$ = $-79$ km s$^{-1}$ cloud we measure total log $N$(H$_2$) $\geq$ 16.75 cm$^{-2}$, molecular fraction $f_\mathrm{H_2}$ $\geq$ 0.8%, and $T_{01}$ $\geq$ 97 and $T_{25}$ $\leq$ 439 K for the ground- and excited-state rotational excitation temperatures. At $v_\mathrm{LSR}$ = $-108$ km s$^{-1}$, we measure log $N$(H$_2$) = 16.13 $\pm$ 0.10 cm$^{-2}$, $f_\mathrm{H_2}$ $\geq$ 0.5%, and $T_{01}$ = 77$^{+34}_{-18}$ and $T_{25}$ = 1092$^{+149}_{-117}$ K, for which the excited state ortho- to para-H$_2$ is 1.0$^{+0.3}_{-0.1}$, much less than the equilibrium value of 3 expected for gas at this temperature. This non-equilibrium ratio suggests that the $-108$ km s$^{-1}$ cloud has been recently excited and has not yet had time to equilibrate. As the LS 4825 sight line passes close by a tilted section of the Galactic disk, we propose that we are probing a boundary region where the nuclear wind is removing gas from the disk.}, number={1}, journal={ASTROPHYSICAL JOURNAL LETTERS}, author={Cashman, Frances H. and Fox, Andrew J. and Savage, Blair D. and Wakker, Bart P. and Krishnarao, Dhanesh and Benjamin, Robert A. and Richter, Philipp and Ashley, Trisha and Jenkins, Edward B. and Lockman, Felix J. and et al.}, year={2021}, month={Dec} }
@article{the cgm$^2$ survey: circumgalactic o vi from dwarf to massive star-forming galaxies_2021, journal={The Astrophysical Journal}, year={2021}, month={Oct} }
@article{ashley_fox_jenkins_wakker_bordoloi_lockman_savage_karim_2020, title={Mapping Outflowing Gas in the Fermi Bubbles: A UV Absorption Survey of the Galactic Nuclear Wind}, volume={898}, ISSN={["1538-4357"]}, DOI={10.3847/1538-4357/ab9ff8}, abstractNote={Abstract Using new ultraviolet (UV) spectra of five background quasars from the Cosmic Origins Spectrograph on the Hubble Space Telescope, we analyze the low-latitude ( ) regions of the Fermi Bubbles, the giant gamma-ray-emitting lobes at the Galactic Center. We combine these data with previous UV and atomic hydrogen (H i ) data sets to build a comprehensive picture of the kinematics and metal column densities of the cool outflowing clouds entrained in the Fermi Bubbles. We find that the number of UV absorption components per sight line decreases as a function of increasing latitude, suggesting that the outflowing clouds become less common with increasing latitude. The Fermi Bubble H i clouds are accelerated up to b ∼ 7°, whereas when we model the UV Fermi Bubbles clouds’ deprojected flow velocities, we find that they are flat or even accelerating with distance from the Galactic center. This trend, which holds in both the northern and southern hemispheres, indicates that the nuclear outflow accelerates clouds throughout the Fermi Bubbles or has an acceleration phase followed by a coasting phase. Finally, we note the existence of several blueshifted high-velocity clouds at latitudes exceeding ∼30°, whose velocities cannot be explained by gas clouds confined to the inside of the gamma-ray-defined Fermi Bubbles. These anomalous-velocity clouds are likely in front of the Fermi Bubbles and could be remnants from past nuclear outflows. Overall, these observations form a valuable set of empirical data on the properties of cool gas in nuclear winds from star-forming galaxies.}, number={2}, journal={ASTROPHYSICAL JOURNAL}, author={Ashley, Trisha and Fox, Andrew J. and Jenkins, Edward B. and Wakker, Bart P. and Bordoloi, Rongmon and Lockman, Felix J. and Savage, Blair D. and Karim, Tanveer}, year={2020}, month={Aug} }
@article{lehner_berek_howk_wakker_tumlinson_jenkins_prochaska_augustin_ji_faucher-giguere_et al._2020, title={Project AMIGA: The Circumgalactic Medium of Andromeda}, volume={900}, ISSN={["1538-4357"]}, DOI={10.3847/1538-4357/aba49c}, abstractNote={Project AMIGA (Absorption Maps In the Gas of Andromeda) is a large ultraviolet Hubble Space Telescope program, which has assembled a sample of 43 QSOs that pierce the circumgalactic medium (CGM) of Andromeda (M31) from R=25 to 569 kpc (25 of them probing gas from 25 kpc to about the virial radius-Rvir = 300 kpc-of M31). Our large sample provides an unparalleled look at the physical conditions and distribution of metals in the CGM of a single galaxy using ions that probe a wide range of gas phases (Si II, Si III, Si IV, C II, C IV, and O VI, the latter being from the Far Ultraviolet Spectroscopic Explorer). We find that Si III and O VI have near unity covering factor maintained all the way out to 1.2Rvir and 1.9Rvir, respectively. We show that Si III is the dominant ion over Si II and Si IV at any R. While we do not find that the properties of the CGM of M31 depend strongly on the azimuth, we show that they change remarkably around 0.3-0.5Rvir, conveying that the inner regions of the CGM of M31 are more dynamic and have more complicated multi-phase gas-structures than at R>0.5Rvir. We estimate the metal mass of the CGM within Rvir as probed by Si II, Si III, and Si IV is 2x10^7 Msun and by O VI is >8x10^7 Msun, while the baryon mass of the 10^4-10^5.5 K gas is ~4x10^10 (Z/0.3 Zsun)^(-1) Msun within Rvir. We show that different zoom-in cosmological simulations of L* galaxies better reproduce the column density profile of O VI with R than Si III or the other studied ions. We find that observations of the M31 CGM and zoom-in simulations of L* galaxies have both lower ions showing higher column density dispersion and dependence on R than higher ions, indicating that the higher ionization structures are larger and/or more broadly distributed.}, number={1}, journal={ASTROPHYSICAL JOURNAL}, author={Lehner, Nicolas and Berek, Samantha C. and Howk, J. Christopher and Wakker, Bart P. and Tumlinson, Jason and Jenkins, Edward B. and Prochaska, J. Xavier and Augustin, Ramona and Ji, Suoqing and Faucher-Giguere, Claude-Andre and et al.}, year={2020}, month={Sep} }
@article{burchett_elek_tejos_prochaska_tripp_bordoloi_forbes_2020, title={Revealing the Dark Threads of the Cosmic Web}, volume={891}, ISSN={["2041-8213"]}, DOI={10.3847/2041-8213/ab700c}, abstractNote={Modern cosmology predicts that matter in our Universe has assembled today into a vast network of filamentary structures colloquially termed the Cosmic Web. Because this matter is either electromagnetically invisible (i.e., dark) or too diffuse to image in emission, tests of this cosmic web paradigm are limited. Wide-field surveys do reveal web-like structures in the galaxy distribution, but these luminous galaxies represent less than 10% of baryonic matter. Statistics of absorption by the intergalactic medium (IGM) via spectroscopy of distant quasars support the model yet have not conclusively tied the diffuse IGM to the web. Here, we report on a new method inspired by the Physarum polycephalum slime mold that is able to infer the density field of the Cosmic Web from galaxy surveys. Applying our technique to galaxy and absorption-line surveys of the local Universe, we demonstrate that the bulk of the IGM indeed resides in the Cosmic Web. From the outskirts of Cosmic Web filaments, at approximately the cosmic mean matter density (rho_m) and approx. 5 virial radii from nearby galaxies, we detect an increasing H I absorption signature towards higher densities and the circumgalactic medium, to approx. 200 rho_m. However, the absorption is suppressed within the densest environments, suggesting shock-heating and ionization deep within filaments and/or feedback processes within galaxies.}, number={2}, journal={ASTROPHYSICAL JOURNAL LETTERS}, author={Burchett, Joseph N. and Elek, Oskar and Tejos, Nicolas and Prochaska, J. Xavier and Tripp, Todd M. and Bordoloi, Rongmon and Forbes, Angus G.}, year={2020}, month={Mar} }
@article{cooper_simcoe_cooksey_bordoloi_miller_furesz_turner_banados_2019, title={Heavy Element Absorption Systems at 5.0 < z < 6.8: Metal-poor Neutral Gas and a Diminishing Signature of Highly Ionized Circumgalactic Matter}, volume={882}, ISSN={["1538-4357"]}, DOI={10.3847/1538-4357/ab3402}, abstractNote={Abstract Ratios of different ions of the same element encode ionization information independently from relative abundances in quasar absorption line systems, crucial for understanding the multiphase nature and origin of absorbing gas, particularly at z > 6 where H i cannot be observed. Observational considerations have limited such studies to a small number of sightlines, with most surveys at z > 6 focused upon the statistical properties of individual ions such as Mg ii or C iv . Here we compare high- and low-ionization absorption within 69 intervening systems at z > 5, including 16 systems at z > 6, from Magellan /FIRE spectra of 47 quasars together with a Keck/High Resolution Echelle Spectrometer (HIRES) spectrum of the “ultraluminous” z = 6.3 quasar SDSSJ010013.02+280225.8. The highest redshift absorbers increasingly exhibit low-ionization species alone, consistent with previous single-ion surveys that show the frequency of Mg ii is unchanging with redshift, while C iv absorption drops markedly toward z = 6. We detect no C iv or Si iv in half of all metal-line absorbers at z > 5.7, with stacks not revealing any slightly weaker C iv just below our detection threshold, and most of the other half have . In contrast, only 20% of absorbers at 5.0–5.7 lack high-ionization gas, and a search of 25 HIRES sightlines at z ∼ 3 yielded zero such examples. We infer that these low-ionization high-redshift absorption systems may be analogous to metal-poor damped Ly α systems (∼1% of the absorber population at z ∼ 3), based on incidence rates and absolute and relative column densities. Simple photoionization models suggest that circumgalactic matter at redshift six has systematically lower chemical abundances and experiences a softer ionizing background relative to redshift three.}, number={2}, journal={ASTROPHYSICAL JOURNAL}, author={Cooper, Thomas J. and Simcoe, Robert A. and Cooksey, Kathy L. and Bordoloi, Rongmon and Miller, Daniel R. and Furesz, Gabor and Turner, Monica L. and Banados, Eduardo}, year={2019}, month={Sep} }
@inproceedings{mahler_chisholm_bayliss_rigby_bordoloi_gladders_sharon_2019, title={Megasaura: The definitive UV spectral atlas of star-forming galaxies at cosmic noon}, volume={233}, booktitle={American Astronomical Society Meeting Abstracts# 233}, author={Mahler, Guillaume and Chisholm, John and Bayliss, Matthew and Rigby, Jane and Bordoloi, Rongmon and Gladders, Michael and Sharon, Keren}, year={2019} }
@inproceedings{bordoloi_ashley_fox_lockman_2019, title={New Spectroscopic Constraints on Cool Gas in the Fermi Bubbles}, volume={233}, booktitle={American Astronomical Society Meeting Abstracts# 233}, author={Bordoloi, Rongmon and Ashley, Trisha L and Fox, Andrew J and Lockman, Felix}, year={2019} }
@article{mignoli_feltre_bongiorno_calura_gilli_vignali_zamorani_lilly_le fevre_bardelli_et al._2019, title={Obscured AGN at 1.5 < z < 3.0 from the zCOSMOS-deep Survey I. Properties of the emitting gas in the narrow-line region}, volume={626}, ISSN={["1432-0746"]}, DOI={10.1051/0004-6361/201935062}, abstractNote={We select a sample of 90 obscured (type2) AGN with 1.45 0 km s −1 ) populations, and using observational constraints on the distance, metallicity, dust content, covering fractions, and total silicon column density of each population. After removing HVCs associated with the Magellanic Stream and the Fermi Bubbles, we find inflow and outflow rates in cool ( T ∼ 10 4 K) ionized gas of dM in / dt ≳ (0.53 ± 0.23)( d /12 kpc)( Z /0.2 Z ⊙ ) −1 M ⊙ yr −1 and dM out / dt ≳ (0.16 ± 0.07)( d /12 kpc)( Z /0.5 Z ⊙ ) −1 M ⊙ yr −1 . The apparent excess of inflowing over outflowing gas suggests that the MW is currently in an inflow-dominated phase, but the presence of substantial mass flux in both directions supports a Galactic fountain model, in which gas is constantly recycled between the disk and the halo. We also find that the metal flux in both directions (in and out) is indistinguishable. By comparing the outflow rate to the Galactic star formation rate, we present the first estimate of the mass loading factor ( η HVC ) of the disk-wide MW wind, finding η HVC ≳ (0.10 ± 0.06)( d /12 kpc)( Z /0.5 Z ⊙ ) −1 . Including the contributions from low- and intermediate-velocity clouds and from hot gas would increase these inflow and outflow estimates.}, number={1}, journal={ASTROPHYSICAL JOURNAL}, author={Fox, Andrew J. and Richter, Philipp and Ashley, Trisha and Heckman, Timothy M. and Lehner, Nicolas and Werk, Jessica K. and Bordoloi, Rongmon and Peeples, Molly S.}, year={2019}, month={Oct} }
@article{prochaska_macquart_mcquinn_simha_shannon_day_marnoch_ryder_deller_bannister_et al._2019, title={The low density and magnetization of a massive galaxy halo exposed by a fast radio burst}, volume={366}, ISSN={["1095-9203"]}, DOI={10.1126/science.aay0073}, abstractNote={Probing a galaxy halo with a radio burst Fast radio bursts (FRBs) are millisecond flashes of radio emission from distant galaxies. It has only recently become possible to locate single bursts precisely enough to determine the host galaxy. Prochaska et al. have observed and localized a FRB using a radio interferometer. The line of sight to the host galaxy coincidentally passes through the outskirts of a closer foreground galaxy. By analyzing the propagation of the FRB, the authors put constraints on the density and magnetization of gas in the outskirts of the foreground galaxy. The technique provides complementary information to existing methods using background quasars. Science , this issue p. 231}, number={6462}, journal={SCIENCE}, author={Prochaska, J. Xavier and Macquart, Jean-Pierre and McQuinn, Matthew and Simha, Sunil and Shannon, Ryan M. and Day, Cherie K. and Marnoch, Lachlan and Ryder, Stuart and Deller, Adam and Bannister, Keith W. and et al.}, year={2019}, month={Oct}, pages={231-+} }
@inproceedings{karim_fox_jenkins_bordoloi_wakker_savage_lockman_crawford_bland-hawthorn_jorgenson_2018, title={A Statistical Study of the Southern Fermi Bubble in UV Absorption Spectra}, volume={231}, booktitle={American Astronomical Society Meeting Abstracts}, author={Karim, Md Tanveer and Fox, Andrew and Jenkins, Edward and Bordoloi, Rongmon and Wakker, Bart and Savage, Blair D and Lockman, Felix and Crawford, Steve and Bland-Hawthorn, Joss and Jorgenson, Regina A}, year={2018} }
@article{peek_bordoloi_sana_roman-duval_tumlinson_zheng_2018, title={Lucky Star: Confirming the Distance to USNO-A0600-15865535 and High-velocity Cloud Complex WD}, volume={2}, number={2}, journal={Research Notes of the AAS}, publisher={IOP Publishing}, author={Peek, JEG and Bordoloi, Rongmon and Sana, Hugues and Roman-Duval, Julia and Tumlinson, Jason and Zheng, Yong}, year={2018}, pages={59} }
@article{bordoloi_prochaska_tumlinson_werk_tripp_burchett_2018, title={On the CGM Fundamental Plane: The Halo Mass Dependency of Circumgalactic H i}, volume={864}, number={2}, journal={The Astrophysical Journal}, publisher={IOP Publishing}, author={Bordoloi, Rongmon and Prochaska, J Xavier and Tumlinson, Jason and Werk, Jessica K and Tripp, Todd M and Burchett, Joseph N}, year={2018}, pages={132} }
@article{karim_fox_jenkins_bordoloi_wakker_savage_lockman_crawford_jorgenson_bland-hawthorn_2018, title={Probing the Southern Fermi Bubble in Ultraviolet Absorption Using Distant AGNs}, volume={860}, number={2}, journal={The Astrophysical Journal}, publisher={IOP Publishing}, author={Karim, Md Tanveer and Fox, Andrew J and Jenkins, Edward B and Bordoloi, Rongmon and Wakker, Bart P and Savage, Blair D and Lockman, Felix J and Crawford, Steven M and Jorgenson, Regina A and Bland-Hawthorn, Joss}, year={2018}, pages={98} }
@article{burchett_tripp_prochaska_werk_tumlinson_howk_willmer_lehner_meiring_bowen_et al._2018, title={The COS Absorption Survey of Baryon Harbors (CASBaH): Warm-hot Circumgalactic Gas Reservoirs Traced by Ne VIII Absorption}, journal={arXiv preprint arXiv:1810.06560}, author={Burchett, Joseph N and Tripp, Todd M and Prochaska, J Xavier and Werk, Jessica K and Tumlinson, Jason and Howk, J Christopher and Willmer, Christopher NA and Lehner, Nicolas and Meiring, Joseph D and Bowen, David V and et al.}, year={2018} }
@article{berg_ellison_tumlinson_oppenheimer_horton_bordoloi_schaye_2018, title={The COS-AGN survey: revealing the nature of circumgalactic gas around hosts of active galactic nuclei}, volume={478}, number={3}, journal={Monthly Notices of the Royal Astronomical Society}, publisher={Oxford University Press}, author={Berg, Trystyn AM and Ellison, Sara L and Tumlinson, Jason and Oppenheimer, Benjamin D and Horton, Ryan and Bordoloi, Rongmon and Schaye, Joop}, year={2018}, pages={3890–3934} }
@article{the magellan evolution of galaxies spectroscopic and ultraviolet reference atlas (megasaura). ii. stacked spectra_2018, volume={853}, number={1}, journal={The Astrophysical Journal}, publisher={IOP Publishing}, year={2018}, pages={87} }
@article{heckman_borthakur_wild_schiminovich_bordoloi_2017, title={COS-burst: Observations of the Impact of Starburst-driven Winds on the Properties of the Circum-galactic Medium}, volume={846}, number={2}, journal={The Astrophysical Journal}, publisher={IOP Publishing}, author={Heckman, Timothy and Borthakur, Sanchayeeta and Wild, Vivienne and Schiminovich, David and Bordoloi, Rongmon}, year={2017}, pages={151} }
@article{almeida_hayden_recio-blanco_laverny_mikolaitis_worley_pillitteri_wolk_megeath_kainulainen_et al._2017, title={Call for candidates for three Associate Editors E1}, author={Almeida, Andre Moitinho and Hayden, MR and Recio-Blanco, A and Laverny, P and Mikolaitis, S and Worley, CC and Pillitteri, I and Wolk, SJ and Megeath, ST and Kainulainen, J and et al.}, year={2017} }
@article{chisholm_bordoloi_rigby_bayliss_2017, title={Feeding the fire: Tracing the mass-loading of 107 K galactic outflows with O vi absorption}, volume={474}, number={2}, journal={Monthly Notices of the Royal Astronomical Society}, publisher={Oxford University Press}, author={Chisholm, J and Bordoloi, R and Rigby, JR and Bayliss, M}, year={2017}, pages={1688–1704} }
@inproceedings{burchett_tripp_wang_willmer_prochaska_werk_bordoloi_katz_tumlinson_2017, title={Galaxy-environment Interactions as Revealed by the Circumgalactic Medium}, volume={229}, booktitle={American Astronomical Society Meeting Abstracts}, author={Burchett, Joseph and Tripp, Todd M and Wang, Daniel and Willmer, Christopher and Prochaska, Jason X and Werk, Jessica and Bordoloi, Rongmon and Katz, Neal and Tumlinson, Jason}, year={2017} }
@article{bordoloi_fox_lockman_wakker_jenkins_savage_hernandez_tumlinson_bland-hawthorn_kim_2017, title={Mapping the Nuclear Outflow of the Milky Way: Studying the Kinematics and Spatial Extent of the Northern Fermi Bubble}, volume={834}, number={2}, journal={The Astrophysical Journal}, publisher={IOP Publishing}, author={Bordoloi, Rongmon and Fox, Andrew J and Lockman, Felix J and Wakker, Bart P and Jenkins, Edward B and Savage, Blair D and Hernandez, Svea and Tumlinson, Jason and Bland-Hawthorn, Joss and Kim, Tae-Sun}, year={2017}, pages={191} }
@article{savage_kim_fox_massa_bordoloi_jenkins_lehner_bland-hawthorn_lockman_hernandez_et al._2017, title={Probing the Outflowing Multiphase Gas~ 1 kpc below the Galactic Center}, volume={232}, number={2}, journal={The Astrophysical Journal Supplement Series}, publisher={IOP Publishing}, author={Savage, Blair D and Kim, Tae-Sun and Fox, Andrew J and Massa, Derck and Bordoloi, Rongmon and Jenkins, Edward B and Lehner, Nicolas and Bland-Hawthorn, Joss and Lockman, Felix J and Hernandez, Svea and et al.}, year={2017}, pages={25} }
@article{bayliss_sharon_acharyya_gladders_rigby_bian_bordoloi_runnoe_dahle_kewley_et al._2017, title={Spatially Resolved Patchy Ly$α$ Emission within the Central Kiloparsec of a Strongly Lensed Quasar Host Galaxy at z= 2.8}, volume={845}, number={2}, journal={The Astrophysical Journal Letters}, publisher={IOP Publishing}, author={Bayliss, Matthew B and Sharon, Keren and Acharyya, Ayan and Gladders, Michael D and Rigby, Jane R and Bian, Fuyan and Bordoloi, Rongmon and Runnoe, Jessie and Dahle, Hakon and Kewley, Lisa and et al.}, year={2017}, pages={L14} }
@article{bordoloi_wagner_heckman_norman_2017, title={The Formation and Physical Origin of Highly Ionized Cooling Gas}, volume={848}, number={2}, journal={The Astrophysical Journal}, publisher={IOP Publishing}, author={Bordoloi, Rongmon and Wagner, Alexander Y and Heckman, Timothy M and Norman, Colin A}, year={2017}, pages={122} }
@article{rivera-thorsen_dahle_gronke_bayliss_rigby_simcoe_bordoloi_turner_furesz_2017, title={The Sunburst Arc: Direct Lyman $α$ escape observed in the brightest known lensed galaxy}, volume={608}, journal={Astronomy & Astrophysics}, publisher={EDP Sciences}, author={Rivera-Thorsen, T Emil and Dahle, Håkon and Gronke, Max and Bayliss, Matthew and Rigby, JR and Simcoe, Robert and Bordoloi, Rongmon and Turner, Monica and Furesz, Gabor}, year={2017}, pages={L4} }
@article{burchett_tripp_bordoloi_werk_prochaska_tumlinson_willmer_o’meara_katz_2016, title={A Deep Search for Faint Galaxies Associated with Very Low Redshift C IV Absorbers. III. The Mass-and Environment-dependent Circumgalactic Medium}, volume={832}, number={2}, journal={The Astrophysical Journal}, publisher={IOP Publishing}, author={Burchett, Joseph N and Tripp, Todd M and Bordoloi, Rongmon and Werk, Jessica K and Prochaska, J Xavier and Tumlinson, Jason and Willmer, CNA and O’Meara, John and Katz, Neal}, year={2016}, pages={124} }
@inproceedings{burchett_tripp_bordoloi_willmer_2016, title={A Deep Search for Galaxies Associated With Very Low-redshift Metal-line Absorbers: The Circumgalactic Media of Dwarf Galaxies and Environmental Effects}, volume={227}, booktitle={American Astronomical Society Meeting Abstracts# 227}, author={Burchett, Joseph and Tripp, Todd M and Bordoloi, Rongmon and Willmer, Christopher}, year={2016} }
@article{ford_werk_davé_tumlinson_bordoloi_katz_kollmeier_oppenheimer_peeples_prochaska_et al._2016, title={Baryon cycling in the low-redshift circumgalactic medium: a comparison of simulations to the COS-Halos survey}, volume={459}, number={2}, journal={Monthly Notices of the Royal Astronomical Society}, publisher={Oxford University Press}, author={Ford, Amanda Brady and Werk, Jessica K and Davé, Romeel and Tumlinson, Jason and Bordoloi, Rongmon and Katz, Neal and Kollmeier, Juna A and Oppenheimer, Benjamin D and Peeples, Molly S and Prochaska, Jason X and et al.}, year={2016}, pages={1745–1763} }
@article{bordoloi_rigby_tumlinson_bayliss_sharon_gladders_wuyts_2016, title={Spatially resolved galactic wind in lensed galaxy RCSGA 032727-132609}, volume={458}, number={2}, journal={Monthly Notices of the Royal Astronomical Society}, publisher={The Royal Astronomical Society}, author={Bordoloi, Rongmon and Rigby, Jane R and Tumlinson, Jason and Bayliss, Matthew B and Sharon, Keren and Gladders, Michael G and Wuyts, Eva}, year={2016}, pages={1891–1908} }
@article{peek_bordoloi_sana_roman-duval_tumlinson_zheng_2016, title={The First Distance Constraint on the Renegade High-velocity Cloud Complex WD}, volume={828}, number={2}, journal={The Astrophysical Journal Letters}, publisher={IOP Publishing}, author={Peek, JEG and Bordoloi, Rongmon and Sana, Hugues and Roman-Duval, Julia and Tumlinson, Jason and Zheng, Yong}, year={2016}, pages={L20} }
@inproceedings{gennaro_robberto_heckman_smee_barkhouser_ninkov_adamo_becker_bellini_bianchi_et al._2016, title={The GMOX science case: resolving galaxies through cosmic time}, volume={9908}, booktitle={Ground-based and Airborne Instrumentation for Astronomy VI}, author={Gennaro, Mario and Robberto, Massimo and Heckman, Timothy and Smee, Stephen A and Barkhouser, Robert and Ninkov, Zoran and Adamo, Angela and Becker, George and Bellini, Andrea and Bianchi, Luciana and et al.}, year={2016}, pages={990849} }
@inproceedings{fox_bordoloi_jenkins_savage_hernandez_wakker_bland-hawthorn_lockman_tumlinson_2016, title={The Kinematics of the Milky Way's Biconical Nuclear Wind}, volume={227}, booktitle={American Astronomical Society Meeting Abstracts# 227}, author={Fox, Andrew and Bordoloi, Rongmon and Jenkins, Edward B and Savage, Blair D and Hernandez, Svea and Wakker, Bart P and Bland-Hawthorn, Jonathan and Lockman, Felix J and Tumlinson, Jason}, year={2016} }
@article{borthakur_heckman_tumlinson_bordoloi_kauffmann_catinella_schiminovich_davé_moran_saintonge_2016, title={The Properties of the Circumgalactic Medium in Red and Blue Galaxies: Results from the COS-GASS+ COS-Halos Surveys}, volume={833}, number={2}, journal={The Astrophysical Journal}, publisher={IOP Publishing}, author={Borthakur, Sanchayeeta and Heckman, Timothy and Tumlinson, Jason and Bordoloi, Rongmon and Kauffmann, Guinevere and Catinella, Barbara and Schiminovich, David and Davé, Romeel and Moran, Sean M and Saintonge, Amelie}, year={2016}, pages={259} }
@article{burchett_tripp_prochaska_werk_tumlinson_o’meara_bordoloi_katz_willmer_2016, title={VizieR Online Data Catalog: z< 0.16 CIV absorbers from HST/COS QSOs spectra (Burchett+, 2015)}, volume={181}, journal={VizieR Online Data Catalog}, author={Burchett, JN and Tripp, TM and Prochaska, JX and Werk, JK and Tumlinson, J and O’Meara, JM and Bordoloi, R and Katz, N and Willmer, CNA}, year={2016} }
@article{a deep search for faint galaxies associated with very low-redshift c iv absorbers. ii. program design, absorption-line measurements, and absorber statistics_2015, volume={815}, number={2}, journal={The Astrophysical Journal}, publisher={IOP Publishing}, year={2015}, pages={91} }
@inproceedings{borthakur_heckman_tumlinson_bordoloi_catinella_schiminovich_2015, title={Connection Between the Circumgalactic Medium and the Atomic Hydrogen in Galaxies}, volume={225}, booktitle={American Astronomical Society Meeting Abstracts}, author={Borthakur, Sanchayeeta and Heckman, Timothy and Tumlinson, Jason and Bordoloi, Rongmon and Catinella, Barbara and Schiminovich, David}, year={2015} }
@article{borthakur_heckman_tumlinson_bordoloi_thom_catinella_schiminovich_davé_kauffmann_moran_et al._2015, title={Connection between the Circumgalactic Medium and the Interstellar Medium of Galaxies: Results from the COS-GASS Survey}, volume={813}, number={1}, journal={The Astrophysical Journal}, publisher={IOP Publishing}, author={Borthakur, Sanchayeeta and Heckman, Timothy and Tumlinson, Jason and Bordoloi, Rongmon and Thom, Christopher and Catinella, Barbara and Schiminovich, David and Davé, Romeel and Kauffmann, Guinevere and Moran, Sean M and et al.}, year={2015}, pages={46} }
@article{fox_bordoloi_savage_lockman_jenkins_wakker_bland-hawthorn_hernandez_kim_benjamin_et al._2015, title={Probing the Fermi Bubbles in Ultraviolet Absorption: A Spectroscopic Signature of the Milky Way's Biconical Nuclear Outflow}, volume={799}, number={1}, journal={The Astrophysical Journal Letters}, publisher={IOP Publishing}, author={Fox, Andrew J and Bordoloi, Rongmon and Savage, Blair D and Lockman, Felix J and Jenkins, Edward B and Wakker, Bart P and Bland-Hawthorn, Joss and Hernandez, Svea and Kim, Tae-Sun and Benjamin, Robert A and et al.}, year={2015}, pages={L7} }
@inproceedings{fox_jenkins_hernandez_savage_bordoloi_wakker_bland-hawthorn_lockman_tumlinson_bowen_et al._2015, title={Probing the Milky Way's Nuclear Wind with QSO Absorption Lines}, volume={225}, booktitle={American Astronomical Society Meeting Abstracts}, author={Fox, Andrew and Jenkins, Edward B and Hernandez, Svea and Savage, Blair D and Bordoloi, Rongmon and Wakker, Bart P and Bland-Hawthorn, Jonathan and Lockman, Felix J and Tumlinson, Jason and Bowen, David V and et al.}, year={2015} }
@article{rigby_gladders_sharon_wuyts_bayliss_bordoloi_2015, title={What lensed galaxies say about winds and physical conditions in high-z galaxies}, volume={22}, journal={IAU General Assembly}, author={Rigby, Jane and Gladders, Michael and Sharon, Keren and Wuyts, Eva and Bayliss, Matthew B and Bordoloi, Rongmon}, year={2015} }
@article{bordoloi_2014, title={How Galaxy Mergers Affect Their Environment: Mapping the Multiphase Circumgalactic Medium of Close Kinematic Pairs}, journal={HST Proposal}, author={Bordoloi, Rongmon}, year={2014} }
@article{bordoloi_lilly_kacprzak_churchill_2014, title={Modeling the distribution of Mg II absorbers around galaxies using background galaxies and quasars}, volume={784}, number={2}, journal={The Astrophysical Journal}, publisher={IOP Publishing}, author={Bordoloi, Rongmon and Lilly, Simon J and Kacprzak, Glenn G and Churchill, Christopher W}, year={2014}, pages={108} }
@inproceedings{tumlinson_bordoloi_team_2014, title={The CGM around Dwarf Galaxies}, volume={223}, booktitle={American Astronomical Society Meeting Abstracts# 223}, author={Tumlinson, Jason and Bordoloi, R and Team, COS-Halos}, year={2014} }
@inproceedings{bordoloi_tumlinson_werk_thom_prochaska_tripp_katz_dave_oppenheimer_ford_et al._2014, title={The CGM around dwarf galaxies}, volume={223}, booktitle={American Astronomical Society Meeting Abstracts# 223}, author={Bordoloi, Rongmon and Tumlinson, J and Werk, J and Thom, C and Prochaska, JX and Tripp, TM and Katz, N and Dave, R and Oppenheimer, B and Ford, A Brady and et al.}, year={2014} }
@article{tumlinson_bordoloi_o’meara_werk_2014, title={The CGM in HD: New Maps of Galactic Accretion, Quenching, and Chemical Feedback in the Circumgalactic Medium}, journal={NOAO Proposal}, author={Tumlinson, Jason and Bordoloi, Rongmon and O’Meara, John and Werk, Jessica}, year={2014} }
@article{werk_prochaska_tumlinson_peeples_tripp_fox_lehner_thom_o’meara_ford_et al._2014, title={The COS-halos survey: physical conditions and baryonic mass in the low-redshift circumgalactic medium}, volume={792}, number={1}, journal={The Astrophysical Journal}, publisher={IOP Publishing}, author={Werk, Jessica K and Prochaska, J Xavier and Tumlinson, Jason and Peeples, Molly S and Tripp, Todd M and Fox, Andrew J and Lehner, Nicolas and Thom, Christopher and O’Meara, John M and Ford, Amanda Brady and et al.}, year={2014}, pages={8} }
@article{bordoloi_lilly_hardmeier_contini_kneib_le fevre_mainieri_renzini_scodeggio_zamorani_et al._2014, title={The dependence of Galactic outflows on the properties and orientation of zCOSMOS galaxies at z~ 1}, volume={794}, number={2}, journal={The Astrophysical Journal}, publisher={IOP Publishing}, author={Bordoloi, R and Lilly, Simon J and Hardmeier, E and Contini, T and Kneib, J-P and Le Fevre, O and Mainieri, V and Renzini, A and Scodeggio, M and Zamorani, G and et al.}, year={2014}, pages={130} }
@article{tasca_tresse_le fèvre_ilbert_lilly_zamorani_lópez-sanjuan_ho_bardelli_cattaneo_et al._2014, title={The zCOSMOS redshift survey: evolution of the light in bulges and discs since z̃ 0.8}, volume={564}, journal={Astronomy & Astrophysics}, publisher={EDP Sciences}, author={Tasca, LAM and Tresse, L and Le Fèvre, O and Ilbert, O and Lilly, SJ and Zamorani, G and López-Sanjuan, C and Ho, LC and Bardelli, S and Cattaneo, A and et al.}, year={2014}, pages={L12} }
@article{bordoloi_tumlinson_werk_oppenheimer_peeples_prochaska_tripp_katz_davé_fox_et al._2014, title={the COS-Dwarfs survey: the carbon reservoir around sub-L* galaxies}, volume={796}, number={2}, journal={The Astrophysical Journal}, publisher={IOP Publishing}, author={Bordoloi, Rongmon and Tumlinson, Jason and Werk, Jessica K and Oppenheimer, Benjamin D and Peeples, Molly S and Prochaska, J Xavier and Tripp, Todd M and Katz, Neal and Davé, Romeel and Fox, Andrew J and et al.}, year={2014}, pages={136} }
@article{vitale_mignoli_cimatti_lilly_carollo_contini_kneib_le fevre_mainieri_renzini_et al._2013, title={Investigating the relationship between AGN activity and stellar mass in zCOSMOS galaxies at 0< z< 1 using emission-line diagnostic diagrams}, volume={556}, journal={Astronomy & Astrophysics}, publisher={EDP Sciences}, author={Vitale, M and Mignoli, M and Cimatti, Alessandro and Lilly, Simon J and Carollo, C Marcella and Contini, T and Kneib, J-P and Le Fevre, O and Mainieri, V and Renzini, A and et al.}, year={2013}, pages={A11} }
@article{mignoli_vignali_gilli_comastri_zamorani_bolzonella_bongiorno_lamareille_nair_pozzetti_et al._2013, title={Obscured AGN at z̃ 1 from the zCOSMOS-Bright Survey-I. Selection and optical properties of a [Ne v]-selected sample}, volume={556}, journal={Astronomy & Astrophysics}, publisher={EDP Sciences}, author={Mignoli, M and Vignali, C and Gilli, R and Comastri, A and Zamorani, G and Bolzonella, M and Bongiorno, A and Lamareille, F and Nair, P and Pozzetti, L and et al.}, year={2013}, pages={A29} }
@article{diener_lilly_knobel_zamorani_lemson_kampczyk_scoville_carollo_contini_kneib_et al._2013, title={Proto-groups at 1.8< z< 3 in the zCOSMOS-deep sample}, volume={765}, number={2}, journal={The Astrophysical Journal}, publisher={IOP Publishing}, author={Diener, Catrina and Lilly, SJ and Knobel, Christian and Zamorani, Gianni and Lemson, G and Kampczyk, P and Scoville, N and Carollo, CM and Contini, T and Kneib, J-P and et al.}, year={2013}, pages={109} }
@article{moresco_pozzetti_cimatti_zamorani_bolzonella_lamareille_mignoli_zucca_lilly_carollo_et al._2013, title={Spot the difference-Impact of different selection criteria on observed properties of passive galaxies in zCOSMOS-20k sample}, volume={558}, journal={Astronomy & Astrophysics}, publisher={EDP Sciences}, author={Moresco, M and Pozzetti, L and Cimatti, Alessandro and Zamorani, G and Bolzonella, M and Lamareille, F and Mignoli, M and Zucca, E and Lilly, SJ and Carollo, CM and et al.}, year={2013}, pages={A61} }
@article{the colors of central and satellite galaxies in zcosmos out to z≃ 0.8 and implications for quenching_2013, volume={769}, number={1}, journal={The Astrophysical Journal}, publisher={IOP Publishing}, year={2013}, pages={24} }
@article{fox_lehner_tumlinson_howk_tripp_prochaska_o’meara_werk_bordoloi_katz_et al._2013, title={The high-ion content and kinematics of low-redshift lyman limit systems}, volume={778}, number={2}, journal={The Astrophysical Journal}, publisher={IOP Publishing}, author={Fox, Andrew J and Lehner, Nicolas and Tumlinson, Jason and Howk, J Christopher and Tripp, Todd M and Prochaska, J Xavier and O’Meara, John M and Werk, Jessica K and Bordoloi, Rongmon and Katz, Neal and et al.}, year={2013}, pages={187} }
@article{knobel_lilly_carollo_contini_kneib_le fevre_mainieri_renzini_scodeggio_zamorani_et al._2012, title={A group-galaxy cross-correlation function analysis in zCOSMOS}, volume={755}, number={1}, journal={The Astrophysical Journal}, publisher={IOP Publishing}, author={Knobel, Christian and Lilly, Simon J and Carollo, C Marcella and Contini, T and Kneib, J-P and Le Fevre, O and Mainieri, V and Renzini, A and Scodeggio, M and Zamorani, G and et al.}, year={2012}, pages={48} }
@article{presotto_iovino_scodeggio_cucciati_knobel_bolzonella_oesch_finoguenov_tanaka_kovač_et al._2012, title={A journey from the outskirts to the cores of groups-I. Color-and mass-segregation in 20K-zCOSMOS groups}, volume={539}, journal={Astronomy & Astrophysics}, publisher={EDP Sciences}, author={Presotto, V and Iovino, A and Scodeggio, M and Cucciati, O and Knobel, C and Bolzonella, M and Oesch, P and Finoguenov, A and Tanaka, M and Kovač, K and et al.}, year={2012}, pages={A55} }
@article{kampczyk_lilly_de ravel_le fèvre_bolzonella_carollo_diener_knobel_kovač_maier_et al._2012, title={Environmental effects in the interaction and merging of galaxies in zCOSMOS}, volume={762}, number={1}, journal={The Astrophysical Journal}, publisher={IOP Publishing}, author={Kampczyk, Pawel and Lilly, SJ and De Ravel, L and Le Fèvre, O and Bolzonella, M and Carollo, CM and Diener, C and Knobel, C and Kovač, K and Maier, C and et al.}, year={2012}, pages={43} }
@article{moresco_cimatti_jimenez_pozzetti_zamorani_bolzonella_dunlop_lamareille_mignoli_pearce_et al._2012, title={Improved constraints on the expansion rate of the Universe up to z~ 1.1 from the spectroscopic evolution of cosmic chronometers}, volume={2012}, number={08}, journal={Journal of Cosmology and Astroparticle Physics}, publisher={IOP Publishing}, author={Moresco, Michele and Cimatti, Alessandro and Jimenez, Raul and Pozzetti, L and Zamorani, G and Bolzonella, M and Dunlop, J and Lamareille, F and Mignoli, M and Pearce, H and et al.}, year={2012}, pages={006} }
@phdthesis{bordoloi_2012, title={Mapping gas around galaxies at high redshifts}, school={ETH Zurich}, author={Bordoloi, Rongmon}, year={2012} }
@article{bordoloi_lilly_amara_oesch_bardelli_zucca_vergani_nagao_murayama_shioya_et al._2012, title={Photo-z performance for precision cosmology--II. Empirical verification}, volume={421}, number={2}, journal={Monthly Notices of the Royal Astronomical Society}, publisher={Blackwell Publishing Ltd Oxford, UK}, author={Bordoloi, R and Lilly, SJ and Amara, A and Oesch, PA and Bardelli, S and Zucca, E and Vergani, D and Nagao, T and Murayama, T and Shioya, Y and et al.}, year={2012}, pages={1671–1677} }
@inproceedings{bordoloi_2012, title={Radial And Azimuthal Profiles Of Mg II Absorption Around Galaxies At 0.5< Z< 0.7}, volume={219}, booktitle={American Astronomical Society Meeting Abstracts# 219}, author={Bordoloi, Rongmon}, year={2012} }
@article{knobel_lilly_iovino_kovač_bschorr_presotto_oesch_kampczyk_carollo_contini_et al._2012, title={THE zCOSMOS* 20k GROUP CATALOG}, volume={753}, number={2}, journal={The Astrophysical Journal}, publisher={IOP Publishing}, author={Knobel, Christian and Lilly, Simon J and Iovino, A and Kovač, Katarina and Bschorr, TJ and Presotto, V and Oesch, Pascal A and Kampczyk, Pawel and Carollo, C Marcella and Contini, T and et al.}, year={2012}, pages={121} }
@article{amara_lilly_kovač_rhodes_massey_zamorani_carollo_contini_kneib_le fevre_et al._2012, title={The COSMOS density field: a reconstruction using both weak lensing and galaxy distributions}, volume={424}, number={1}, journal={Monthly Notices of the Royal Astronomical Society}, publisher={The Royal Astronomical Society}, author={Amara, Adam and Lilly, Simon and Kovač, Katarina and Rhodes, J and Massey, R and Zamorani, G and Carollo, CM and Contini, T and Kneib, J-P and Le Fevre, O and et al.}, year={2012}, pages={553–563} }
@article{lópez-sanjuan_le fèvre_ilbert_tasca_bridge_cucciati_kampczyk_pozzetti_xu_carollo_et al._2012, title={The dominant role of mergers in the size evolution of massive early-type galaxies since z̃ 1}, volume={548}, journal={Astronomy & Astrophysics}, publisher={EDP Sciences}, author={López-Sanjuan, C and Le Fèvre, O and Ilbert, O and Tasca, LAM and Bridge, C and Cucciati, O and Kampczyk, P and Pozzetti, L and Xu, CK and Carollo, CM and et al.}, year={2012}, pages={A7} }
@article{x-ray groups of galaxies at 0.5 $łt$ z $łt$ 1 in zcosmos: increased agn activities in high redshift groups_2012, volume={64}, DOI={10.1093/pasj/64.2.22}, abstractNote={Abstract We present a photometric and spectroscopic study of galaxies at 0.5 $\lt$${z}$$\lt$ 1 as a function of the environment based on data from the zCOSMOS survey. There is a fair amount of evidence that galaxy properties depend on the mass of groups and clusters, in the sense that quiescent galaxies prefer more massive systems. We base our analysis on a mass-selected environment using X-ray groups of galaxies, and define the group membership using a large number of spectroscopic redshifts from zCOSMOS. We show that the fraction of red galaxies is higher in groups than in the field at all redshifts probed in our study. Interestingly, the fraction of [O II] emitters on the red sequence increases at higher redshifts in groups, while the fraction does not strongly evolve in the field. This is due to increased dusty star-formation activities and/or increased activities of active galactic nuclei (AGNs) in high-redshift groups. We investigate these possibilities using the 30-band photometry and X-ray data. We find that the stellar population of the red [O II] emitters in groups is old, and there is no clear hint of dusty star-formation activities in those galaxies. The observed increase of red [O II] emitters in groups is likely due to increased AGN activities. However, since our overall statistics are poor, any firm conclusions need to be drawn from a larger statistical sample of ${z}$$\sim$ 1 groups.}, journal={\pasj}, year={2012}, month={Apr}, pages={22} }
@article{tanaka_finoguenov_lilly_bolzonella_carollo_contini_iovino_kneib_lamareille_le fevre_et al._2012, title={X-Ray Groups of Galaxies at 0.5 1 in zCOSMOS: Increased AGN Activities in High Redshift Groups}, volume={64}, number={2}, journal={Publications of the Astronomical Society of Japan}, publisher={Oxford University Press}, author={Tanaka, Masayuki and Finoguenov, Alexis and Lilly, Simon J and Bolzonella, Micol and Carollo, C Marcella and Contini, Thierry and Iovino, Angela and Kneib, Jean-Paul and Lamareille, Fabrice and Le Fevre, Olivier and et al.}, year={2012} }
@article{bordoloi_lilly_knobel_bolzonella_kampczyk_carollo_iovino_zucca_contini_kneib_et al._2011, title={The radial and azimuthal profiles of Mg II absorption around 0.5< z< 0.9 zCOSMOS Galaxies of different colors, masses, and environments}, volume={743}, number={1}, journal={The Astrophysical Journal}, publisher={IOP Publishing}, author={Bordoloi, Rongmon and Lilly, Simon J and Knobel, Christian and Bolzonella, M and Kampczyk, Pawel and Carollo, C Marcella and Iovino, A and Zucca, E and Contini, T and Kneib, J-P and et al.}, year={2011}, pages={10} }
@article{peng_lilly_kovač_bolzonella_pozzetti_renzini_zamorani_ilbert_knobel_iovino_et al._2010, title={Mass and Environment as Drivers of Galaxy Evolution in SDSS and zCOSMOS and the Origin of the Schechter Function}, volume={721}, number={1}, journal={The Astrophysical Journal}, publisher={IOP Publishing}, author={Peng, Ying-jie and Lilly, Simon J and Kovač, Katarina and Bolzonella, Micol and Pozzetti, Lucia and Renzini, Alvio and Zamorani, Gianni and Ilbert, Olivier and Knobel, Christian and Iovino, Angela and et al.}, year={2010}, pages={193} }
@article{bordoloi_lilly_amara_2010, title={Photo-z performance for precision cosmology}, volume={406}, number={2}, journal={Monthly Notices of the Royal Astronomical Society}, publisher={The Royal Astronomical Society}, author={Bordoloi, Rongmon and Lilly, Simon J and Amara, Adam}, year={2010}, pages={881–895} }
@article{bordoloi_2009, title={Effect of Photo-z on precision cosmology}, author={Bordoloi, Rongmon}, year={2009} }
@article{tanaka_finoguenov_lilly_bolzonella_carollo_contini_iovino_kneib_lamareille_le fevre_et al., title={PASJ: publications of the Astronomical Society of Japan 50 (2), 241-248, 1998-04-25}, author={TANAKA, Masayuki and FINOGUENOV, Alexis and LILLY, Simon J and BOLZONELLA, Micol and CAROLLO, C Marcella and CONTINI, Thierry and IOVINO, Angela and KNEIB, Jean-Paul and LAMAREILLE, Fabrice and LE FEVRE, Olivier and et al.} }