Follow-up Survey for the Binary Black Hole Merger GW200224_222234 Using Subaru/HSC and GTC/OSIRIS

Abstract The LIGO/Virgo detected a gravitational wave (GW) event, named GW200224_222234 (also known as S200224ca) and classified as a binary-black hole coalescence, on 2020 February 24. Given its relatively small localization skymap (71 deg 2 for a 90% credible region; revised to 50 deg 2 in GWTC-3)...

Full description

Saved in:

Bibliographic Details
Published in:	The Astrophysical journal 2023-04, Vol.947 (1), p.9
Main Authors:	Ohgami, Takayuki, González, Josefa Becerra, Tominaga, Nozomu, Morokuma, Tomoki, Utsumi, Yousuke, Niino, Yuu, Tanaka, Masaomi, Banerjee, Smaranika, Poidevin, Frédérick, Acosta-Pulido, Jose Antonio, Pérez-Fournon, Ismael, Muñoz-Darias, Teo, Akitaya, Hiroshi, Yanagisawa, Kenshi, Sasada, Mahito, Yoshida, Michitoshi, Simunovic, Mirko, Ohsawa, Ryou, Tanaka, Ichi, Terai, Tsuyoshi, Takagi, Yuhei
Format:	Article
Language:	eng
Subjects:	ASTRONOMY AND ASTROPHYSICS Astrophysics Black holes Coalescence Curve fitting Galaxies Gravitational waves Localization Luminosity Optical counterparts (astronomy) Sky surveys (astronomy) Spectroscopy Surveys
Online Access:	Get full text
Tags:	Add Tag No Tags, Be the first to tag this record!

Description
Summary:	Abstract The LIGO/Virgo detected a gravitational wave (GW) event, named GW200224_222234 (also known as S200224ca) and classified as a binary-black hole coalescence, on 2020 February 24. Given its relatively small localization skymap (71 deg 2 for a 90% credible region; revised to 50 deg 2 in GWTC-3), we performed target-of-opportunity observations using the Subaru/Hyper Suprime-Cam (HSC) in the r 2 and z bands. Observations were conducted on 2020 February 25 and 28 and March 23, with the first epoch beginning 12.3 hr after the GW detection. The survey covered the highest-probability sky area of 56.6 deg 2 , corresponding to a 91% probability. This was the first deep follow-up ( m r ≳ 24, m z ≳ 23) for a binary-black hole merger covering >90% of the localization. By performing image subtraction and candidate screening including light-curve fitting with transient templates and examples, we found 22 off-nucleus transients that were not ruled out as the counterparts of GW200224_222234 with our Subaru/HSC data alone. We also performed GTC/OSIRIS spectroscopy of the probable host galaxies for five candidates; two are likely to be located within the 3D skymap, whereas the others are not. In conclusion, 19 transients remain as possible optical counterparts of GW200224_222234; but we could not identify a unique promising counterpart. If there are no counterparts in the remaining candidates, the upper limits of the optical luminosity are ν L ν < 5.2 − 1.9 + 2.4 × 10 41 erg s −1 and ν L ν < 1.8 − 0.6 + 0.8 × 10 42 erg s −1 in the r 2 and z bands, respectively, at ∼12 hr after GW detection. We also discuss improvements in the strategies of optical follow-ups for future GW events.
ISSN:	0004-637X 1538-4357