Limits on the ejecta mass during the search for kilonovae associated with neutron star-black hole mergers: a case study of S230518h, GW230529, S230627c and the low-significance candidate S240422ed

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68378271%3A_____%2F25%3A00641753" target="_blank" >RIV/68378271:_____/25:00641753 - isvavai.cz</a>

Result on the web

<a href="https://doi.org/10.1103/6ld6-95xh" target="_blank" >https://doi.org/10.1103/6ld6-95xh</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1103/6ld6-95xh" target="_blank" >10.1103/6ld6-95xh</a>

Result language

angličtina

Original language name

Limits on the ejecta mass during the search for kilonovae associated with neutron star-black hole mergers: a case study of S230518h, GW230529, S230627c and the low-significance candidate S240422ed

Original language description

Neutron star-black hole (NSBH) mergers, detectable via their gravitational-wave (GW) emission, are expected to produce kilonovae (KNe). Four NSBH candidates have been identified and followed-up by more than fifty instruments since the start of the fourth GW observing run (O4), in May 2023, up to July 2024, however, no confirmed associated KN has been detected. This study evaluates ejecta properties from multimessenger observations to understand the absence of detectable KN: we use GW public information and joint observations taken from 05.2023 to 07.2024 (LVK, ATLAS, DECam, GECKO, GOTO, GRANDMA, SAGUARO, TESS, WINTER, ZTF). First, our analysis on follow-up observation strategies shows that, on average, more than 50% of the simulated KNe associated with NSBH mergers reach their peak luminosity around one day after merger in the g, r, i- bands, which is not necessarily covered for each NSBH GW candidate. We also analyze the trade-off between observation efficiency and the intrinsic properties of the KN emission, to understand the impact on how these constraints affect our ability to detect the KN, and underlying ejecta properties for each GW candidate. In particular, we can only confirm the kilonova was not missed for 1% of the GW230529 and S230627c sky localization region, given the large sky localization error of GW230529 and the large distance for S230627c and, their respective KN faint luminosities. More constraining, for S230518h, we infer the dynamical ejecta and postmerger disk wind ejecta mdyn,mwind<0.03⁢M and the viewing angle 0 >25°. Similarly, the nonastrophysical origin of S240422ed is likely further confirmed by the fact that we would have detected even a faint KN at the time and presumed distance of the S240422ed event candidate, within a minimum 45% credible region of the sky area, that can be larger depending on the KN scenario.n

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

10303 - Particles and field physics

Project

Result was created during the realization of more than one project. More information in the Projects tab.

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2025

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Physical Review D

ISSN

2470-0010

e-ISSN

2470-0029

Volume of the periodical

112

Issue of the periodical within the volume

8

Country of publishing house

US - UNITED STATES

Number of pages

41

Pages from-to

083002

UT code for WoS article

001598985600001

EID of the result in the Scopus database

2-s2.0-105020647289