Bulletin of the American Physical Society
APS April Meeting 2019
Volume 64, Number 3
Saturday–Tuesday, April 13–16, 2019; Denver, Colorado
Session H16: What we learned from GW170817 and what we'll learn from future events |
Hide Abstracts |
Sponsoring Units: DAP DGRAV Chair: Duncan Brown, Syracuse University Room: Sheraton Grand Ballroom I |
Sunday, April 14, 2019 10:45AM - 10:57AM |
H16.00001: Properties of the binary neutron star merger GW170817 Aaron Zimmerman On August 17, 2017, Advanced LIGO and Advanced Virgo detectors observed the gravitational wave signal GW170817. This signal was consistent with the inspiral and eventual merger of a pair of neutron stars. Analysis of the gravitational waves, together with the detection of radiation from this event throughout the electromagnetic spectrum, has advanced our understanding of neutron stars and their composition. In this talk I report on improved estimates of the properties of the binary over those initially reported, using only gravitational wave data and the known source location. These properties include the component masses, spins, and tidal parameters. The improvements are due to the use of more detailed models, finalized calibration of the data, and a greater range of gravitational-wave frequencies considered. |
Sunday, April 14, 2019 10:57AM - 11:09AM |
H16.00002: Searching for evidence of measurable p-g mode instability in GW170817 Steven D Reyes, Duncan A. Brown It has been suggested by Weinberg et al. (2013) that an instability due to nonlinear coupling of a neutron star's tide to its pressure and gravity (p-g) modes could affect the gravitational-wave inspiral of a binary neutron star. Using a parameterized model for nonlinear tides from Essick et al. (2016) we search for evidence of measurable p-g modes using Bayesian inference. We investigate a measurability condition where we examine nonlinear tidal parameters that induce a gravitational wave phase shift at the innermost stable circular orbit greater than 0.1 radians. We find that this model is consistent with GW170817. We also investigate a stronger measurability condition where we search for nonlinear tides with a mismatch greater than 0.04 with a standard post-Newtonian waveform family. |
Sunday, April 14, 2019 11:09AM - 11:21AM |
H16.00003: Tidal Deformabilities and Radii of Neutron Stars from the Observation of GW170817 Soumi De, Daniel Finstad, James M Lattimer, Duncan A. Brown, Edo Berger, Christopher M Biwer On August 17, 2017 LIGO and Virgo made the first observation of a binary neutron star coalescence, GW170817. We present measurements of the tidal deformabilities and radii of the neutron stars in the GW170817 binary from the analysis of the gravitational-wave data incorporating information from nuclear matter studies. We also briefly discuss prospects for further improvements in the accuracy of parameter measurements and extraction of nuclear equation of state physics from the gravitational-wave data. |
Sunday, April 14, 2019 11:21AM - 11:33AM |
H16.00004: Universal Relations after GW170817 Zack Carson, Katerina Chatziioannou, Carl-Johan O Haster, Nicolas Yunes, Kent Yagi The equation of state of supranuclear matter is critical to the study of neutron stars, and is one of |
Sunday, April 14, 2019 11:33AM - 11:45AM |
H16.00005: Effects of spin on magnetized binary neutron star mergers and jet launching. Milton Ruiz, Antonios Tsokaros, Stuart Louis Shapiro Events GW170817 and GRB 170817A provide the best confirmation so far that binary neutron star (BNS) mergers can be the progenitors of short gamma-ray bursts (sGRBs). An open question for GW170817 remains the spin of the remnant black hole (BH), which may have a strong impact on the formation and lifetime of a jet and the outgoing Poynting luminosity. We report GRMHD simulations of spinning, magnetized, BNSs undergoing merger and delayed collapse. The BNSs consist of two identical NS, modeled as $\Gamma=2$ polytropes, in quasicircular orbit endowed with a pulsar-like B-fields. Following merger, magnetic instabilities and the loss of angular momentum due to gravitational radiation in the hypermassive NS (HMNS) induce the formation of a nearly uniformly rotating inner core and a Keplerian disk envelope. The HMNS collapses to a BH, with spin $a/M_{\rm BH} \sim 0.75$ independent of the initial spin of the NS. After $3000M-4000 M \sim 45-60(M_{\rm NS}/1.625M_\odot)\rm ms$ following BH formation, an incipient jet is launched. The lifetime of the jets [$\Delta t\sim 100-140(M_{\rm NS}/1.625M_\odot)\rm ms$] and their Poynting luminosities [$L_{jet}\sim 10^{51.5\pm 1}\rm erg/s$] are consistent with typical sGRBs, as well as with the Blandford--Znajek mechanism for launching jets. |
Sunday, April 14, 2019 11:45AM - 11:57AM |
H16.00006: Constraining Short Gamma-Ray Burst Jet Properties Using Coincident Gravitational Wave and Electromagnetic Detections Andrea S Biscoveanu, Eric Thrane, Salvatore Vitale The simultaneous detection of GW170817 and GRB170817A ushered in the era of multi messenger astronomy, confirming the hypothesis that binary neutron star mergers are the progenitors of at least some short gamma-ray bursts. GRB prompt emission is thought to be highly beamed, but determining the opening angle of the jet traditionally relies on the observation of a jet break in the afterglow since the inclination angle of the system is unknown. Coincident gravitational wave observations of short GRBs from binary neutron star mergers, however, provide an independent measurement of the inclination angle and distance to the source. We describe a Bayesian method for determining the morphology of short GRBs using coincident electromagnetic and gravitational-wave observations. In particular, we show that is possible to measure the gamma-ray burst opening angle, Lorentz factor, and total energy for a particular event, and that by studying a population of such coincident detections the distributions of these parameters can also be inferred. |
Sunday, April 14, 2019 11:57AM - 12:09PM |
H16.00007: Future Science with Neutron Star Mergers Eric Burns The first multimessenger detection of a neutron star merger uncovered a wealth of science that spanned several fields of physics. As the gravitational wave interferometers improve in the coming years, multimessenger detections of these events will become routine. We will discuss how studies of these events can inform on the astrophysics of the events themselves, fundamental physics, particle acceleration in the extreme regime, the equation of state of supranuclear matter, and cosmology, and the astrophysical observations necessary to uncover them. |
Follow Us |
Engage
Become an APS Member |
My APS
Renew Membership |
Information for |
About APSThe American Physical Society (APS) is a non-profit membership organization working to advance the knowledge of physics. |
© 2024 American Physical Society
| All rights reserved | Terms of Use
| Contact Us
Headquarters
1 Physics Ellipse, College Park, MD 20740-3844
(301) 209-3200
Editorial Office
100 Motor Pkwy, Suite 110, Hauppauge, NY 11788
(631) 591-4000
Office of Public Affairs
529 14th St NW, Suite 1050, Washington, D.C. 20045-2001
(202) 662-8700