LIGO/Virgo/KAGRA S230704f: Identification of a GW compact binary merger candidate
Abstract
We identified the compact binary merger candidate S230704f during real-time processing of data from LIGO Hanford Observatory (H1) and LIGO Livingston Observatory (L1) at 2023-07-04 02:12:11.224 UTC (GPS time: 1372471949.224). The candidate was found by the CWB [1], MBTA [2], and GstLAL [3] analysis pipelines. S230704f is an event of interest because its false alarm rate, as estimated by the online analysis, is 2.8e-09 Hz, or about one in 11 years. The event's properties can be found at this URL: https://gracedb.ligo.org/superevents/S230704f The classification of the GW signal, in order of descending probability, is BBH (>99%), Terrestrial (<1%), NSBH (<1%), or BNS (<1%). Assuming the candidate is astrophysical in origin, the probability that the lighter compact object is consistent with a neutron star mass (HasNS) is <1%. [4] Using the masses and spins inferred from the signal, the probability of matter outside the final compact object (HasRemnant) is <1%. [4] Both HasNS and HasRemnant consider the support of several neutron star equations of state. The probability that either of the binary components lies between 3 and 5 solar masses (HasMassgap) is <1%. Two sky maps are available at this time and can be retrieved from the GraceDB event page: * bayestar.multiorder.fits,0, an initial localization generated by BAYESTAR [5], distributed via GCN notice about 23 seconds after the candidate event time. * bayestar.multiorder.fits,1, an initial localization generated by BAYESTAR [5], distributed via GCN notice about 5 minutes after the candidate event time. The preferred sky map at this time is bayestar.multiorder.fits,1. For the bayestar.multiorder.fits,1 sky map, the 90% credible region is 1948 deg2. Marginalized over the whole sky, the a posteriori luminosity distance estimate is 2965 +/- 978 Mpc (a posteriori mean +/- standard deviation). For further information about analysis methodology and the contents of this alert, refer to the LIGO/Virgo/KAGRA Public Alerts User Guide https://emfollow.docs.ligo.org/userguide/. [1] Klimenko et al. PRD 93, 042004 (2016) [2] Aubin et al. CQG 38, 095004 (2021) [3] Tsukada et al. arXiv:2305.06286 (2023) and Ewing et al. arXiv:2305.05625 (2023) [4] Chatterjee et al. ApJ 896, 54 (2020) [5] Singer & Price PRD 93, 024013 (2016)
- Publication:
-
GRB Coordinates Network
- Pub Date:
- July 2023
- Bibcode:
- 2023GCN.34140....1L