@article{baxter_benzvi_jaimes_coleiro_molla_dornic_goldhagen_graf_griswold_habig_et al._2022, title={SNEWPY: A Data Pipeline from Supernova Simulations to Neutrino Signals}, volume={925}, ISSN={["1538-4357"]}, DOI={10.3847/1538-4357/ac350f}, abstractNote={Abstract}, number={2}, journal={ASTROPHYSICAL JOURNAL}, author={Baxter, Amanda L. and BenZvi, Segev and Jaimes, Joahan Castaneda and Coleiro, Alexis and Molla, Marta Colomer and Dornic, Damien and Goldhagen, Tomer and Graf, Anne and Griswold, Spencer and Habig, Alec and et al.}, year={2022}, month={Feb} }
 @article{deaton_o'connor_zhu_bohn_jesse_foucart_duez_mclaughlin_2018, title={Elastic scattering in general relativistic ray tracing for neutrinos}, volume={98}, ISSN={["2470-0029"]}, DOI={10.1103/PhysRevD.98.103014}, abstractNote={We present a covariant ray tracing algorithm for computing high-resolution neutrino distributions in general relativistic numerical spacetimes with hydrodynamical sources. Our formulation treats th ...}, number={10}, journal={PHYSICAL REVIEW D}, author={Deaton, M. Brett and O'Connor, Evan and Zhu, Y. L. and Bohn, Andy and Jesse, Jerred and Foucart, Francois and Duez, Matthew D. and McLaughlin, G. C.}, year={2018}, month={Nov} }
 @article{o'connor_boilig_burrows_couch_fischer_janka_kotake_lentz_liebendoerfer_messer_et al._2018, title={Global comparison of core-collapse supernova simulations in spherical symmetry}, volume={45}, ISSN={["1361-6471"]}, DOI={10.1088/1361-6471/aadeae}, abstractNote={We present a comparison between several simulation codes designed to study the core-collapse supernova mechanism. We pay close attention to controlling the initial conditions and input physics in order to ensure a meaningful and informative comparison. Our goal is three-fold. First, we aim to demonstrate the current level of agreement between various groups studying the core-collapse supernova central engine. Second, we desire to form a strong basis for future simulation codes and methods to compare to. Lastly, we want this work to be a stepping stone for future work exploring more complex simulations of core-collapse supernovae, i.e., simulations in multiple dimensions and simulations with modern neutrino and nuclear physics. We compare the early (first ~500ms after core bounce) spherically-symmetric evolution of a 20 solar mass progenitor star from six different core-collapse supernovae codes: 3DnSNe-IDSA, AGILE-BOLTZTRAN, FLASH, F{\sc{ornax}}, GR1D, and PROMETHEUS-VERTEX. Given the diversity of neutrino transport and hydrodynamic methods employed, we find excellent agreement in many critical quantities, including the shock radius evolution and the amount of neutrino heating. Our results provide an excellent starting point from which to extend this comparison to higher dimensions and compare the development of hydrodynamic instabilities that are crucial to the supernova explosion mechanism, such as turbulence and convection.}, number={10}, journal={JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS}, author={O'Connor, Evan and Boilig, Robert and Burrows, Adam and Couch, Sean and Fischer, Tobias and Janka, Hans-Thomas and Kotake, Kei and Lentz, Eric J. and Liebendoerfer, Matthias and Messer, O. E. Bronson and et al.}, year={2018}, month={Oct} }
 @article{evan p. o'connor_couch_2018, title={Two-dimensional Core-collapse Supernova Explosions Aided by General Relativity with Multidimensional Neutrino Transport}, volume={854}, ISSN={["1538-4357"]}, DOI={10.3847/1538-4357/aaa893}, abstractNote={Abstract}, number={1}, journal={ASTROPHYSICAL JOURNAL}, author={Evan P. O'Connor and Couch, Sean M.}, year={2018}, month={Feb} }
 @article{richers_ott_abdikamalov_o'connor_sullivan_2017, title={Equation of state effects on gravitational waves from rotating core collapse}, volume={95}, ISSN={["2470-0029"]}, DOI={10.1103/physrevd.95.063019}, abstractNote={Gravitational waves (GWs) generated by axisymmetric rotating collapse, bounce, and early postbounce phases of a galactic core-collapse supernova are detectable by current-generation gravitational wave observatories. Since these GWs are emitted from the quadrupole-deformed nuclear-density core, they may encode information on the uncertain nuclear equation of state (EOS). We examine the effects of the nuclear EOS on GWs from rotating core collapse and carry out 1824 axisymmetric general-relativistic hydrodynamic simulations that cover a parameter space of 98 different rotation profiles and 18 different EOS. We show that the bounce GW signal is largely independent of the EOS and sensitive primarily to the ratio of rotational to gravitational energy, T/|W|, and at high rotation rates, to the degree of differential rotation. The GW frequency (f_(peak)∼600–1000  Hz) of postbounce core oscillations shows stronger EOS dependence that can be parametrized by the core’s EOS-dependent dynamical frequency √Gρc. We find that the ratio of the peak frequency to the dynamical frequency f_(peak)/√Gρc follows a universal trend that is obeyed by all EOS and rotation profiles and that indicates that the nature of the core oscillations changes when the rotation rate exceeds the dynamical frequency. We find that differences in the treatments of low-density nonuniform nuclear matter, of the transition from nonuniform to uniform nuclear matter, and in the description of nuclear matter up to around twice saturation density can mildly affect the GW signal. More exotic, higher-density physics is not probed by GWs from rotating core collapse. We furthermore test the sensitivity of the GW signal to variations in the treatment of nuclear electron capture during collapse. We find that approximations and uncertainties in electron capture rates can lead to variations in the GW signal that are of comparable magnitude to those due to different nuclear EOS. This emphasizes the need for reliable experimental and/or theoretical nuclear electron capture rates and for self-consistent multidimensional neutrino radiation-hydrodynamic simulations of rotating core collapse.}, number={6}, journal={PHYSICAL REVIEW D}, author={Richers, Sherwood and Ott, Christian D. and Abdikamalov, Ernazar and O'Connor, Evan and Sullivan, Chris}, year={2017}, month={Mar} }
 @article{horowitz_caballero_lin_o'connor_schwenk_2017, title={Neutrino-nucleon scattering in supernova matter from the virial expansion}, volume={95}, ISSN={["2469-9993"]}, DOI={10.1103/physrevc.95.025801}, abstractNote={We generalize our virial approach to study the neutral current neutrino response of nuclear matter at low densities. In the long-wavelength limit, the virial expansion makes model-independent predictions for neutrino-nucleon scattering rates and the density S_V and spin S_A responses. We find S_A is significantly reduced from one even at low densities. We provide a simple fit S_A^f(n,T,Y_p) of the axial response as a function of density n, temperature T and proton fraction Y_p. This fit reproduces our model independent virial results at low densities and reproduces the Burrows and Sawyer random phase approximation (RPA) results at high densities. Our fit can be incorporated into supernova simulations in a straight forward manner. Preliminary one dimensional supernova simulations suggest that the reduction in the axial response may enhance neutrino heating rates in the gain region during the accretion phase of a core-collapse supernovae.}, number={2}, journal={PHYSICAL REVIEW C}, author={Horowitz, C. J. and Caballero, O. L. and Lin, Zidu and O'Connor, Evan and Schwenk, A.}, year={2017}, month={Feb} }
 @article{roberts_ott_haas_evan p. o'connor_diener_schnetter_2016, title={GENERAL-RELATIVISTIC THREE-DIMENSIONAL MULTI-GROUP NEUTRINO RADIATION-HYDRODYNAMICS SIMULATIONS OF CORE-COLLAPSE SUPERNOVAE}, volume={831}, ISSN={["1538-4357"]}, DOI={10.3847/0004-637x/831/1/98}, abstractNote={ABSTRACT}, number={1}, journal={ASTROPHYSICAL JOURNAL}, author={Roberts, Luke F. and Ott, Christian D. and Haas, Roland and Evan P. O'Connor and Diener, Peter and Schnetter, Erik}, year={2016}, month={Nov} }
 @article{foucart_o'connor_roberts_kidder_pfeiffer_scheel_2016, title={Impact of an improved neutrino energy estimate on outflows in neutron star merger simulations}, volume={94}, ISSN={["2470-0029"]}, DOI={10.1103/physrevd.94.123016}, abstractNote={Binary neutron star mergers are promising sources of gravitational waves for ground-based detectors such as Advanced LIGO. Neutron-rich material ejected by these mergers may also be the main source of r-process elements in the Universe, while radioactive decays in the ejecta can power bright electromagnetic postmerger signals. Neutrino-matter interactions play a critical role in the evolution of the composition of the ejected material, which significantly impacts the outcome of nucleosynthesis and the properties of the associated electromagnetic signal. In this work, we present a simulation of a binary neutron star merger using an improved method for estimating the average neutrino energies in our energy-integrated neutrino transport scheme. These energy estimates are obtained by evolving the neutrino number density in addition to the neutrino energy and flux densities. We show that significant changes are observed in the composition of the polar ejecta when comparing our new results with earlier simulations in which the neutrino spectrum was assumed to be the same everywhere in optically thin regions. In particular, we find that material ejected in the polar regions is less neutron rich than previously estimated. Our new estimates of the composition of the polar ejecta make it more likely that the color and time scale of the electromagnetic signal depend on the orientation of the binary with respect to an observer’s line of sight. These results also indicate that important observable properties of neutron star mergers are sensitive to the neutrino energy spectrum, and may need to be studied through simulations including a more accurate, energy-dependent neutrino transport scheme.}, number={12}, journal={PHYSICAL REVIEW D}, author={Foucart, Francois and O'Connor, Evan and Roberts, Luke and Kidder, Lawrence E. and Pfeiffer, Harald P. and Scheel, Mark A.}, year={2016}, month={Dec} }
 @article{foucart_haas_duez_o'connor_ott_roberts_kidder_lippuner_pfeiffer_scheel_2016, title={Low mass binary neutron star mergers: Gravitational waves and neutrino emission}, volume={93}, number={4}, journal={Physical Review D}, author={Foucart, F. and Haas, R. and Duez, M. D. and O'Connor, E. and Ott, C. D. and Roberts, L. and Kidder, L. E. and Lippuner, J. and Pfeiffer, H. P. and Scheel, M. A.}, year={2016} }
 @article{sullivan_o'connor_zegers_grubb_austin_2016, title={THE SENSITIVITY OF CORE-COLLAPSE SUPERNOVAE TO NUCLEAR ELECTRON CAPTURE}, volume={816}, ISSN={["1538-4357"]}, DOI={10.3847/0004-637x/816/1/44}, abstractNote={ABSTRACT}, number={1}, journal={ASTROPHYSICAL JOURNAL}, author={Sullivan, Chris and O'Connor, Evan and Zegers, Remco G. T. and Grubb, Thomas and Austin, Sam M.}, year={2016}, month={Jan} }
 @article{lehner_liebling_palenzuela_caballero_o'connor_anderson_neilsen_2016, title={Unequal mass binary neutron star mergers and multimessenger signals}, volume={33}, ISSN={["1361-6382"]}, DOI={10.1088/0264-9381/33/18/184002}, abstractNote={We study the merger of binary neutron stars with different mass ratios adopting three different realistic, microphysical nuclear equations of state, as well as incorporating neutrino cooling effects. In particular, we concentrate on the influence of the equation of state on the gravitational wave signature and also on its role, in combination with neutrino cooling, in determining the properties of the resulting hypermassive neutron star, of the neutrinos produced, and of the ejected material. The ejecta we find are consistent with other recent studies that find that small mass ratios produce more ejecta than equal mass cases (up to some limit) and this ejecta is more neutron rich. This trend indicates the importance with future kilonovae observations of measuring the individual masses of an associated binary neutron star system, presumably from concurrent gravitational wave observations, in order to be able to extract information about the nuclear equation of state.}, number={18}, journal={CLASSICAL AND QUANTUM GRAVITY}, author={Lehner, Luis and Liebling, Steven L. and Palenzuela, Carlos and Caballero, O. L. and O'Connor, Evan and Anderson, Matthew and Neilsen, David}, year={2016}, month={Sep} }
 @article{o'connor_2015, title={An open-source neutrino radiation hydrodynamics code for core-collapse supernovae}, volume={219}, DOI={10.1088/0067-0049/219/2/24}, abstractNote={We present an open-source update to the spherically symmetric, general-relativistic hydrodynamics, core-collapse supernova (CCSN) code GR1D. The source code is available at http://www.GR1Dcode.org. We extend its capabilities to include a general-relativistic treatment of neutrino transport based on the moment formalisms of Shibata et al. and Cardall et al. We pay special attention to implementing and testing numerical methods and approximations that lessen the computational demand of the transport scheme by removing the need to invert large matrices. This is especially important for the implementation and development of moment-like transport methods in two and three dimensions. A critical component of neutrino transport calculations is the neutrino–matter interaction coefficients that describe the production, absorption, scattering, and annihilation of neutrinos. In this article we also describe our open-source neutrino interaction library NuLib (available at http://www.nulib.org). We believe that an open-source approach to describing these interactions is one of the major steps needed to progress toward robust models of CCSNe and robust predictions of the neutrino signal. We show, via comparisons to full Boltzmann neutrino-transport simulations of CCSNe, that our neutrino transport code performs remarkably well. Furthermore, we show that the methods and approximations we employ to increase efficiency do not decrease the fidelity of our results. We also test the ability of our general-relativistic transport code to model failed CCSNe by evolving a 40-solar-mass progenitor to the onset of collapse to a black hole.}, number={2}, journal={Astrophysical Journal Supplement Series}, author={O'Connor, E.}, year={2015} }
 @article{palenzuela_liebling_neilsen_lehner_caballero_o'connor_anderson_2015, title={Effects of the microphysical equation of state in the mergers of magnetized neutron stars with neutrino cooling}, volume={92}, ISSN={["1550-2368"]}, DOI={10.1103/physrevd.92.044045}, abstractNote={We study the merger of binary neutron stars using different realistic, microphysical nuclear equations of state, as well as incorporating magnetic field and neutrino cooling effects. In particular, we concentrate on the influence of the equation of state on the gravitational wave signature and also on its role, in combination with cooling and electromagnetic effects, in determining the properties of the hypermassive neutron star resulting from the merger, the production of neutrinos, and the characteristics of ejecta from the system. The ejecta we find are consistent with other recent studies that find soft equations of state produce more ejecta than stiffer equations of state. Moreover, the degree of neutron richness increases for softer equations of state. In light of reported kilonova observations (associated to GRB~130603B and GRB~060614) and the discovery of relatively low abundances of heavy, radioactive elements in deep sea deposits (with respect to possible production via supernovae), we speculate that a soft EoS might be preferred---because of its significant production of sufficiently neutron rich ejecta---if such events are driven by binary neutron star mergers. We also find that realistic magnetic field strengths, obtained with a sub-grid model tuned to capture magnetic amplification via the Kelvin-Helmholtz instability at merger, are generally too weak to affect the gravitational wave signature post-merger within a time scale of $\approx 10$~ms but can have subtle effects on the post-merger dynamics.}, number={4}, journal={PHYSICAL REVIEW D}, author={Palenzuela, Carlos and Liebling, Steven L. and Neilsen, David and Lehner, Luis and Caballero, O. L. and O'Connor, Evan and Anderson, Matthew}, year={2015}, month={Aug} }
 @article{richers_kasen_o'connor_fernandez_ott_2015, title={MONTE CARLO NEUTRINO TRANSPORT THROUGH REMNANT DISKS FROM NEUTRON STAR MERGERS}, volume={813}, ISSN={["1538-4357"]}, DOI={10.1088/0004-637x/813/1/38}, abstractNote={We present Sedonu, a new open source, steady-state, special relativistic Monte Carlo (MC) neutrino transport code, available at bitbucket.org/srichers/sedonu. The code calculates the energy- and angle-dependent neutrino distribution function on fluid backgrounds of any number of spatial dimensions, calculates the rates of change of fluid internal energy and electron fraction, and solves for the equilibrium fluid temperature and electron fraction. We apply this method to snapshots from two-dimensional simulations of accretion disks left behind by binary neutron star mergers, varying the input physics and comparing to the results obtained with a leakage scheme for the cases of a central black hole and a central hypermassive neutron star. Neutrinos are guided away from the densest regions of the disk and escape preferentially around 45° from the equatorial plane. Neutrino heating is strengthened by MC transport a few scale heights above the disk midplane near the innermost stable circular orbit, potentially leading to a stronger neutrino-driven wind. Neutrino cooling in the dense midplane of the disk is stronger when using MC transport, leading to a globally higher cooling rate by a factor of a few and a larger leptonization rate by an order of magnitude. We calculate neutrino pair annihilation rates and estimate that an energy of 2.8 × 1046 erg is deposited within 45° of the symmetry axis over 300 ms when a central BH is present. Similarly, 1.9 × 1048 erg is deposited over 3 s when an HMNS sits at the center, but neither estimate is likely to be sufficient to drive a gamma-ray burst jet.}, number={1}, journal={ASTROPHYSICAL JOURNAL}, author={Richers, Sherwood and Kasen, Daniel and O'Connor, Evan and Fernandez, Rodrigo and Ott, Christian D.}, year={2015}, month={Nov} }
 @article{foucart_o'connor_roberts_duez_haas_kidder_ott_pfeiffer_scheel_szilagyi_2015, title={Post-merger evolution of a neutron star-black hole binary with neutrino transport}, volume={91}, number={12}, journal={Physical Review. D, Particles, Fields, Gravitation, and Cosmology}, author={Foucart, F. and O'Connor, E. and Roberts, L. and Duez, M. D. and Haas, R. and Kidder, L. E. and Ott, C. D. and Pfeiffer, H. P. and Scheel, M. A. and Szilagyi, B.}, year={2015} }