A5063290216- Stellar, planetary, and galactic studies
- Gamma-ray bursts and supernovae
- Astrophysical Phenomena and Observations
- Pulsars and Gravitational Waves Research
- High-pressure geophysics and materials
- Astronomy and Astrophysical Research
- Astro and Planetary Science
- Astrophysics and Star Formation Studies
- Astronomical Observations and Instrumentation
- Geophysics and Sensor Technology
- Astrophysics and Cosmic Phenomena
- Mechanics and Biomechanics Studies
- Solar and Space Plasma Dynamics
- Geophysics and Gravity Measurements
- History and Developments in Astronomy
- Nuclear Physics and Applications
- Galaxies: Formation, Evolution, Phenomena
- earthquake and tectonic studies
- Nuclear physics research studies
- Superconducting Materials and Applications
- Particle Accelerators and Free-Electron Lasers
- Adaptive optics and wavefront sensing
- Scientific Measurement and Uncertainty Evaluation
- Atomic and Subatomic Physics Research
- Fluid Dynamics and Turbulent Flows
University of California, Santa Barbara
2015-2024
Kavli Institute for Theoretical Sciences
2002-2023
Kavli Institute for Particle Astrophysics and Cosmology
2008-2017
University of Warwick
2017
University of Göttingen
2017
Astronomical Observatory of Capodimonte
2017
Villanova University
2017
American Association of Variable Star Observers
2017
University of Arizona
2017
University of Southampton
2017
We substantially update the capabilities of open source software package Modules for Experiments in Stellar Astrophysics (MESA), and its one-dimensional stellar evolution module, MESAstar. Improvements MESAstar's ability to model giant planets now extends applicability down masses as low one-tenth that Jupiter. The dramatic improvement asteroseismology enabled by space-based Kepler CoRoT missions motivates our full coupling ADIPLS adiabatic pulsation code with This also a numerical recasting...
Stellar physics and evolution calculations enable a broad range of research in astrophysics. Modules for Experiments Astrophysics (MESA) is suite open source, robust, efficient, thread-safe libraries wide applications computational stellar A one-dimensional module, MESAstar, combines many the numerical modules simulations scenarios ranging from very low mass to massive stars, including advanced evolutionary phases. MESAstar solves fully coupled structure composition equations simultaneously....
We substantially update the capabilities of open-source software instrument Modules for Experiments in Stellar Astrophysics (MESA). MESA can now simultaneously evolve an interacting pair differentially rotating stars undergoing transfer and loss mass angular momentum, greatly enhancing prior ability to model binary evolution. New fully coupled calculation nuclear networks with hundreds isotopes allow accurately simulate advanced burning stages needed construct supernova progenitor models....
The Palomar Transient Factory (PTF) is a fully-automated, wide-field survey aimed at systematic exploration of the optical transient sky. performed using new 8.1 square degree camera installed on 48-inch Samuel Oschin telescope Observatory; colors and light curves for detected transients are obtained with automated 60-inch telescope. PTF uses eighty percent 1.2-m fifty 1.5-m time. With an exposure 60-s reaches depth approximately 21.3 in g' 20.6 R (5 sigma, median seeing). Four major...
The Palomar Transient Factory (PTF) is a wide-field experiment designed to investigate the optical transient and variable sky on time scales from minutes years. PTF uses CFH12k mosaic camera, with field of view 7.9 deg2 plate scale 1'' pixel-1, mounted Observatory 48 inch Samuel Oschin Telescope. operation strategy devised probe existing gaps in phase space search for theoretically predicted, but not yet detected, phenomena, such as fallback supernovae, macronovae,. Ia orphan afterglows...
We summarize 5 years of continuous monitoring accretion-powered pulsars with the Burst and Transient Source Experiment (BATSE) on Compton Gamma Ray Observatory. Our 20-70 keV observations have determined or refined orbital parameters 13 binaries, discovered five new transient accreting pulsars, measured pulsed flux history during outbursts 12 transients (GRO J1744-28, 4U 0115+634, GRO J1750-27, GS 0834-430, 2S 1417-624, J1948+32, EXO 2030+375, J1008-57, A0535+26, J2058+42, 1145-619,...
We update the capabilities of software instrument Modules for Experiments in Stellar Astrophysics (MESA) and enhance its ease use availability. Our new approach to locating convective boundaries is consistent with physics convection, yields reliable values core mass during both hydrogen helium burning phases. Stars $M<8\,{\rm M_\odot}$ become white dwarfs cool point where electrons are degenerate ions strongly coupled, a realm now available study MESA due improved treatments element...
We calculate the rapid proton ( rp) capture process of hydrogen burning on surface an accreting neutron star with updated reaction network that extends up to Xe, far beyond previous work. In both steady-state nuclear appropriate for rapidly stars (such as magnetic polar caps x-ray pulsars) and unstable type I bursts, we find rp ends in a closed SnSbTe cycle. This prevents synthesis elements heavier than Te has important consequences burst profiles, composition stars, potentially galactic...
Gravitational-wave interferometers are expected to monitor the last three minutes of inspiral and final coalescence neutron star black hole binaries at distances approaching cosmological, where event rate may be many per year. Because binary's accumulated orbital phase can measured a fractional accuracy $\ll 10^{-3}$ relativistic effects large, waveforms will far more complex, carry information, harder model theoretically than has been expected. Theorists must begin now lay foundation for...
We show that energy deposited into an expanding supernova remnant by a highly magnetic (B ∼ 5 × 1014 G) neutron star spinning at initial period of Pi ≈ 2–20 ms can substantially brighten the light curve. For magnetars with parameters in this range, rotational is released on timescale days to weeks, which comparable effective diffusion time through remnant. The late injection then be radiated without suffering overwhelming adiabatic expansion losses. magnetar input also produces central...
Recent discoveries by the Rossi X-Ray Timing Explorer indicate that most of rapidly accreting ( ≳ 10−11 M yr−1) weakly magnetic (B≪1011 G) neutron stars in Galaxy are rotating at spin frequencies νs 250 Hz. Remarkably, they all rotate a narrow range (no more than factor 2, with many within 20% 300 Hz). I suggest these fast enough so that, on average, angular momentum added accretion is lost to gravitational radiation. The strong νs-dependence loss rate from radiation then provides natural...
view Abstract Citations (379) References (40) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Tidal Interactions of Inspiraling Compact Binaries Bildsten, Lars ; Cutler, Curt We discuss the tidal interaction in neutron star-neutron star and star-black hole binaries argue that they will not be tidally locked during gravitational inspiral. More specifically, we show that, for inspiraling stars mass greater than about 1.2 solar mass, shortest possible...
Helium that accretes onto a carbon/oxygen white dwarf in double AM Canum Venaticorum (AM CVn) binaries undergoes unstable thermonuclear flashes when the orbital period is 3.5-25 minute range. At shortest periods (and highest accretion rates, > 10-7 M☉ yr-1), are weak and likely lead to helium equivalent of classical nova outbursts. However, as orbit widens drops, mass required for ignition increases, leading progressively more violent up final flash with shell ≈0.02-0.1 M☉. The high...
We update the capabilities of open-knowledge software instrument Modules for Experiments in Stellar Astrophysics (MESA). RSP is a new functionality MESAstar that models non-linear radial stellar pulsations characterize RR Lyrae, Cepheids, and other classes variable stars. significantly enhance numerical energy conservation capabilities, including during mass changes. For example, this enables calculations through He flash conserve to better than 0.001 %. To improve modeling rotating stars...
Stellar Explosions Stars that are born with masses greater than eight times of the Sun end their lives in luminous explosions known as supernovae. Over past decade, access to improved sky surveys has revealed rare types supernovae much more any those were before. Gal-Yam (p. 927 ) reviews these superluminous events and groups them into three classes share common observational physical characteristics. Gamma-ray bursts another type extreme explosive related death massive stars, which occur...
High-quality collections of Type II supernova (SN) light curves are scarce because they evolve for hundreds days, making follow-up observations time consuming and often extending over multiple observing seasons. In these difficulties, the diversity SNe is not fully understood. Here we present ultraviolet optical photometry 12 monitored by Las Cumbres Observatory Global Telescope Network during 2013 to 2014, compare them with previously studied having well-sampled curves. We explore SN...
Asteroseismology of 1.0-2.0 Msun red giants by the Kepler satellite has enabled first definitive measurements interior rotation in both ascent giant branch (RGB) stars and those on Helium burning clump. The inferred rates are 10-30 days for ~0.2Msun He degenerate cores RGB 30-100 core a clump star. Using MESA code we calculate state-of-the-art stellar evolution models low mass rotating from zero-age main sequence to cooling white dwarf (WD) stage. We include transport angular momentum due...
We update the capabilities of open-knowledge software instrument Modules for Experiments in Stellar Astrophysics (MESA). The new auto_diff module implements automatic differentiation MESA, an enabling capability that alleviates need hard-coded analytic expressions or finite difference approximations. significantly enhance treatment growth and decay convection MESA with a model time-dependent convection, which is particularly important during late-stage nuclear burning massive stars electron...
Nuclear reactions occurring at densities ≈ 1012 g cm-3 in the crust of a transiently accreting neutron star efficiently maintain core temperature (5-10)×107 K. When accretion halts, envelope relaxes to thermal equilibrium set by flux from hot core, as if were newly born. For time-averaged rates (≲10-10 M☉ yr-1) typical low-mass X-ray transients, standard neutrino cooling is unimportant and thermally reradiates deposited heat. The resulting luminosity ~5×1032-5×1033 ergs s-1 agrees with many...
Motivated by the remarkably narrow range of measured spin frequencies ∼20 accreting (and weakly magnetic) neutron stars in Galaxy, Bildsten conjectured that their spin-up had been halted emission gravitational waves. If so, then brightest persistent X-ray source on sky, Scorpius X-1, should be detected wave interferometers within 10 years. pointed out small non-axisymmetric temperature variations accreted crust will lead to ‘wavy’ electron capture layers, and resulting horizontal density...