GW190521, the most massive binary black hole merger confidently detected by the LIGO-Virgo-KAGRA Collaboration, is the first gravitational-wave observation of an intermediate-mass black hole. The signal was followed approximately 34 days later by flare ZTF19abanrhr, detected in AGN J 124942.3 + 344929 by the Zwicky Transient Facility at the 78% spatial contour for GW190521’s sky localization. Using the GWTC-2.1 data release, we find that the association between GW190521 and flare ZTF19abanrhr as its electromagnetic counterpart is preferred over a random coincidence of the two transients with a log Bayes’ factor of 8.6, corresponding to an odds ratio of ∼ 5400 : 1 for equal prior odds and ∼ 400 : 1 assuming an astrophysical prior odds of 1 / 13 . Given the association, the multimessenger signal allows for an estimation of the Hubble constant, finding H 0 = 10 2 + 27 − 25 km s − 1 Mpc − 1 when solely analyzing GW190521 and 79.2 + 17.6 − 9.6 km s − 1 Mpc − 1 assuming prior information from the binary neutron star merger GW170817, both consistent with the existing literature.
GW190521: A binary black hole merger inside an active galactic nucleus?
Rinaldi, Stefano
;Del Pozzo, Walter
2023-01-01
Abstract
GW190521, the most massive binary black hole merger confidently detected by the LIGO-Virgo-KAGRA Collaboration, is the first gravitational-wave observation of an intermediate-mass black hole. The signal was followed approximately 34 days later by flare ZTF19abanrhr, detected in AGN J 124942.3 + 344929 by the Zwicky Transient Facility at the 78% spatial contour for GW190521’s sky localization. Using the GWTC-2.1 data release, we find that the association between GW190521 and flare ZTF19abanrhr as its electromagnetic counterpart is preferred over a random coincidence of the two transients with a log Bayes’ factor of 8.6, corresponding to an odds ratio of ∼ 5400 : 1 for equal prior odds and ∼ 400 : 1 assuming an astrophysical prior odds of 1 / 13 . Given the association, the multimessenger signal allows for an estimation of the Hubble constant, finding H 0 = 10 2 + 27 − 25 km s − 1 Mpc − 1 when solely analyzing GW190521 and 79.2 + 17.6 − 9.6 km s − 1 Mpc − 1 assuming prior information from the binary neutron star merger GW170817, both consistent with the existing literature.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
