Simulations of Compact Binary Merger Events in Preparation for Forthcoming LIGO Observing Runs
Emily M. Foley (WFU), R. Weizmann Kendriebeogo (OCA), Michael W. Coughlin (UMN), Andrew M. Toivonen (UMN)
We generate large populations of CBCs based on expected mass, spin, and detection probability distributions. We use two different sampling processes: rates and populations (R&P) and Bayestar-inject. R&P uses previous observing runs as priors, whereas Bayestar-inject generates normal mass and spin distributions.
After these injections were simulated, summary statistics were generated and made available on the LIGO public user guide. These include updated predictions for annual detection rates, sky area, comoving volume, and luminosity distance of the merger events in O4 and O5. The credibility of our results were evaluated by comparing them to O3 public alert data, as well as the 2019 Living Reviews in Relativity (LRR) simulations done by the LIGO and Virgo scientific collaborations [1].
Table II (above). Predicted annual detection rates of CBC mergers for each population and sampling method.
Figure IV (below). Sample skymap for a simulated O4 BNS merger event. Darker red areas represent lower credibility regions, with the event’s actual location denoted by the white star.
Figures I and II (above). Mass and distance distributions for R&P (left) and Bayestar-inject (right) sampling processes which passed the SNR threshold for the detector network as projected for O4 and O5.
Figure III (left). Comparison of our simulations to O3 public alerts. Cumulative fractions of events for 90% credible comoving volume, area, and luminosity distance are shown for O4 BNS, NSBH, and BBH mergers. Empirical distributions 2019 LRR simulations (blue) are compared with R&P (red) and Bayestar-inject distributions. O3 public alerts are denoted in black.
Figures V and VI (above). Peak magnitude distributions for O4 BNS lightcurves. R, G, and I correspond to the filters applied to the telescope. On the left are the magnitudes as would be observed by ZTF, and on the right are Rubin.
Figure VII (left). Median peak magnitudes, extracted from the distributions in Figures V and VI.
Results
1. Public alerts user guide. Observing Capabilities - LIGO/Virgo Public Alerts User Guide 16 documentation. (n.d.). Retrieved August 6, 2022, from https://emfollow.docs.ligo.org/userguide/capabilities.html
2. The LIGO Scientific Collaboration, The Virgo Collaboration, & The KAGRA Collaboration. (2021). The population of merging compact binaries inferred using gravitational waves through GWTC-3. The Astrophysical Journal. https://arxiv.org/abs/2111.03634
3. Petrov, P., Singer et. al (2022). Data-driven expectations for electromagnetic counterpart searches based on LIGO/Virgo Public Alerts. The Astrophysical Journal, 924(2), 54. https://doi.org/10.3847/1538-4357/ac366d
Abstract
Rubin, lightcurves were generated for 50% of events. The figures below summarize the distributions of the peak magnitudes for each lightcurve, as well as median values of the peaks.
Methodology
Conclusions and Future Work
References
School of Physics and Astronomy
This work was supported partially by the
Research Experiences for Undergraduates
(REU) Program of the
National Science Foundation
under Award Number
PHY-2049645