David Vartanyan
I am a Hubble Einstein Fellow at Carnegie Observatories. I was previously a postdoc at Berkeley/LBL as a joint TAC and ECP fellow. I received my Ph.D from Princeton University, studying core-collapse supernovae theory through multi-dimensional simulations.
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My research interests probe the role of both large-scale and small-scale effects, from rotation to neutrino-matter microphysics, to better understand these Titans of Nature.
Publications
9/2018; first author
We present the first 3D study (and successful explosion) of a CCSN progenitor with detailed microphysics and state of the art neutrino transport. We study a 16-M progenitor and find that it explodes slightly earlier in 3D - within 100 ms of bounce - than 2D, features a "wasp's waist" multi-plume morphology, and accumulates energy at the rate of 0.25 Bethe per second.
4/2018
We calculate neutrino light curves for a host of 1D and 2D core-collapse supernova models, and estimate supernovae detection ranges for various physical diagnostics.
06/2018
We present a CCSN code comparison between various groups studying of a 20-M progenitor evolved in spherical symmetry. We introduce benchmarks and metrics to guide future comparison work, and find remarkable similarity in many physical quantities, such as the shock radius and neutrino heating rates, between the various, disparate efforts.
1/2018; first author
We perform a series of 2D core-collapse supernova simulations of progenitors spanning 12-25 M. We find that explosion outcome depends sensitively on microphysics, progenitor profile, and macrophysics. Namely, all models with interior Si-O interfaces explode early on, and all the remaining duds can be exploded with modest rotation and/or perturbations to infall velocity of the progenitor.
1/2018
We study the gravitational waves (GW) from a series of 2D core-collapse supernova simulations. We find that, following 400ms post-bounce, the dominant GW signal is from the fundamental quadrupole oscillation mode of the proto-neutron star. We also present a study of how progenitor profile, equation of state, and explosion mechanism can affect the GW signal.
11/2017
We perform a series of 1D and 2D core-collapse supernova (SN) simulations using FORNAX of a suite of low-mass and electron-capture (EC) progenitors spanning 8-11 M. We find that the ECSN explode relatively easily, and the PNS convection in 2D increases neutrino luminosities by a factor of 2.
2/2018
We perform a series of 2D core-collapse supernova simulations using FORNAX to study how microphysical changes, such as many-body corrections to neutrino-nucleon scattering cross sections and inelastic neutrino-medium scattering, can prompt a dud to explode.