Bulletin of the American Physical Society
APS April Meeting 2018
Volume 63, Number 4
Saturday–Tuesday, April 14–17, 2018; Columbus, Ohio
Session B16: Gravitational Waves: Data Analysis Techniques and Parameter Estimation - I |
Hide Abstracts |
Sponsoring Units: DAP DGRAV Chair: Richard O'Shaughnessy, LIGO Room: B232-233 |
Saturday, April 14, 2018 10:45AM - 10:57AM |
B16.00001: Can LIGO measure the spins of nearly extremal, merging binary black holes? Geoffrey Lovelace, Katerina Chatziioannou Astrophysical evidence suggests that black holes that are nearly extremal (i.e., near the theoretical upper limit) might exist and thus might be among the merging black holes that LIGO observes. If LIGO were to observe gravitational waves from nearly extremal, merging black holes, would parameter estimation recover the rapid spins? In this talk, we test typical LIGO parameter estimation methods on injections of gravitational waveforms from numerical-relativity simulations of nearly-extremal, merging black holes with spins parallel or antiparallel with the orbital angular momentum. We find that recovering the holes' nearly extremal spins is challenging and that a commonly used prior (uniform in spin magnitude and direction) disfavors rapid black-hole spins. [Preview Abstract] |
Saturday, April 14, 2018 10:57AM - 11:09AM |
B16.00002: Measuring the effective spin of binary black holes Ken K. Y. Ng, Salvatore Vitale, Aaron Zimmerman, Carl-Johan Haster, Katerina Chatziioannou, Davide Gerosa Gravitational waves emitted by coalescing compact objects carry information about the spin of the individual bodies. However, what can be measured best is the projection of the total spin along the orbital angular momentum, known as effective spin $\chi_{eff}$. This quantity, is also conserved up the the 2nd post-newtonian order. Various authors have proposed methods to use the measured $\chi_{eff}$ distribution to infer the underlying formation channels. However, care need to be exercised when drawing conclusions. In this talk we will show that a) the bayesian priors used can significantly affect the measurements of $\chi_{eff}$ b) even if the true astrophysical distribution of $\chi_{eff}$ were to be perfectly symmetric, the distribution of detectable $\chi_{eff}$ need not be; and c) the posterior distribution of $\chi_{eff}$ for individual events should not be treated as a gaussian. In particular, we find that the posterior distributions for $\chi_{eff}$ systematically show fatter tails toward larger positive values. Finally, we show that the uncertainties of the measured effective spins are as much as ~8 times larger when the spin is negative than when it is positive, where the amount of additional uncertainty depends on the mass and magnitude of $\chi_{eff}$. [Preview Abstract] |
Saturday, April 14, 2018 11:09AM - 11:21AM |
B16.00003: Systematic Errors and Energy Estimates in Binary Black Hole Ringdown Vishal Baibhav, Emanuele Berti, Vitor Cardoso, Gaurav Khanna High signal-to-noise ratio gravitational wave observations will enable us to measure the quasinormal frequencies of binary black hole merger remnants. In general relativity, these frequencies depend only on the remnant’s mass and spin, so they can be used to test general relativity and the Kerr nature of the remnant. To carry out these tests, systematic errors must be subdominant with respect to statistical errors. We determined how accurately ringdown frequencies can be extracted from state-of-the-art numerical simulations from the Simulating eXtreme Spacetimes (SXS) catalog. We found that at least the first overtone must be included to determine quasinormal frequencies (or the remnant’s spin and mass) within percent accuracy. We also quantified the relative excitation of different quasinormal modes. To address this question one must define a suitable "starting time”, e.g. by maximizing the energy content “parallel" to a quasinormal mode (as suggested by Nollert). We used Nollert's method to quantify the energy radiated in quasinormal modes for aligned-spin binaries, and we produced post-Newtonian inspired fits of the resulting energy estimates. [Preview Abstract] |
Saturday, April 14, 2018 11:21AM - 11:33AM |
B16.00004: Searching for Eccentric Binary Black Holes with BayesWave Belinda Cheeseboro, Sean McWilliams, Paul Baker, Amber Lenon With the detection of gravitational waves from binary black holes (BBH) and binary neutron star (BNS) mergers, we are motivated to improve our sensitivity to gravitational waves from highly eccentric binary black holes (eBBH) sources. We present a method for detecting these sources and possible implementation into BayesWave, an existing algorithm for unmodeled burst searches. From our previous study we used BayesWave to analyze highly eBBH sources, and we found that it was not effectively detecting disconnected bursts in the early part of the waveform. Therefore, we propose a change to the original BayeWave analysis that will help it to connect these disconnected bursts by using the time and frequency information of one burst to get the same for another. We will discuss how this method will work and how it will be implemented into the BayesWave algorithm. [Preview Abstract] |
Saturday, April 14, 2018 11:33AM - 11:45AM |
B16.00005: Influence of higher-order waveform multipoles for the detection of eccentric binary black hole mergers Adam Rebei, Eliu Huerta, Roland Haas, Daniel Johnson Several studies in the literature have quantified the impact of higher-order waveform multipoles for the detection of quasi-circular binary black hole mergers. However, there is no study in the literature that has addressed this important topic in the context of eccentric binary black hole mergers. We shed light on this topic by performing a systematic study of the importance of including higher-order waveform multipoles, in particular the modes \((\ell,\,m)=(2,\,2),\, (3,\,3),\, (4,\,4),\, (2,\,1)\) and \((3,\,2)\), for the detection of eccentric binary black hole mergers. We extract these modes from our catalog of eccentric numerical relativity simulations that describe binary black hole mergers with mass-ratios $q<6$ and eccentricities $e<0.2$ ten cycles before merger. We explore the configurations in which these modes contribute significantly to the signal-to-noise ratio of astrophysically motivated sources, and find that the inclusion of these modes is not critical for the detection of equal mass binary black hole mergers. However, gravitational wave searches that target asymmetric mass-ratio systems should include them. [Preview Abstract] |
Saturday, April 14, 2018 11:45AM - 11:57AM |
B16.00006: Constraining properties of black hole mimickers with gravitational wave observations of binary black holes Nathan Johnson-McDaniel, Arunava Mukherjee, Rahul Kashyap, Parameswaran Ajith, Walter Del Pozzo, Salvatore Vitale, Tanja Hinderer Observations of gravitational waves from compact binary coalescences using the Advanced LIGO and Advanced Virgo detectors are now starting to become routine. All but one of the observations so far has been identified as coming from a binary black hole coalescence. These signals are found to be consistent with the predictions of general relativity for binary black hole coalescences, within statistical uncertainties. However, there remains the possibility that these signals could have been produced by the coalescence of some "black hole mimickers" instead of black holes. Black hole mimickers are massive, dark, compact objects, such as boson stars and gravastars, which can emulate many of the properties of black holes. However, such objects, if they exist, would generically have nonzero tidal deformabilities, while black holes have zero tidal deformability in general relativity. These tidal deformabilities imprint themselves on the gravitational wave signal. Using full Bayesian parameter estimation, we investigate the constraints it is possible to place on the properties of black hole mimickers (e.g., coupling constants for boson stars) if binaries of these objects are to produce the signals detected by LIGO and Virgo. [Preview Abstract] |
Saturday, April 14, 2018 11:57AM - 12:09PM |
B16.00007: Numerical simulations of binary black holes for GW170104 Carlos Lousto, James Healy, Jacob Lange, Richard O'Shaughnessy In response to LIGOs observation of GW170104, we performed a series of full numerical simulations of binary black holes, each designed to replicate likely realizations of its dynamics and radiation. These simulations have been performed at multiple resolutions to solve Einsteins equations. For the nonprecessing and precessing simulations, we demonstrate the precision of the simulations is substantially in excess of what is needed to explain LIGOs observations. Conversely, we demonstrate our full numerical solutions contain information which is not accurately captured with the approximate phenomenological models commonly used to infer compact binary parameters. To quantify the impact of these differences on parameter inference for GW170104 specifically, we compare the predictions of our simulations and these approximate models to LIGOs observations of GW170104. [Preview Abstract] |
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