J-GEM near-infrared follow-up observations of the gravitational wave event S240422ed

Fuente: arXiv
Enregistré dans:
Détails bibliographiques
Auteurs principaux: Takahashi, Ichiro, Morokuma, Tomoki, Tanaka, Masaomi, Sasada, Mahito, Akitaya, Hiroshi, Tanaka, Ichi, Tominaga, Nozomu, Yoshida, Michitoshi, Utsumi, Yousuke, Itoh, Ryosuke, Kawaguchi, Kyohei, collaboration, the J-GEM
Format: Preprint
Publié: 2025
Sujets:
Accès en ligne:
Tags: Ajouter un tag
Pas de tags, Soyez le premier à ajouter un tag!
_version_ 1866908599511416832
author Takahashi, Ichiro
Morokuma, Tomoki
Tanaka, Masaomi
Sasada, Mahito
Akitaya, Hiroshi
Tanaka, Ichi
Tominaga, Nozomu
Yoshida, Michitoshi
Utsumi, Yousuke
Itoh, Ryosuke
Kawaguchi, Kyohei
collaboration, the J-GEM
author_facet Takahashi, Ichiro
Morokuma, Tomoki
Tanaka, Masaomi
Sasada, Mahito
Akitaya, Hiroshi
Tanaka, Ichi
Tominaga, Nozomu
Yoshida, Michitoshi
Utsumi, Yousuke
Itoh, Ryosuke
Kawaguchi, Kyohei
collaboration, the J-GEM
contents We report our near-infrared (NIR) follow-up observations of the gravitational wave (GW) event S240422ed using the Subaru Telescope/MOIRCS. S240422ed was initially classified as a black hole-neutron star merger with $>$ 99% probability of electromagnetic wave emission. We started follow-up observations 7.8 hours after the event. Over two nights, we observed 206 nearby galaxies in $Y$ and $K_{\rm s}$ bands down to about 21.4 and 21.1 AB mag (3$σ$), respectively. The total completeness of our survey based on galaxy $B$-band luminosity is 22%. As a result of our observations, five candidate counterparts were identified. We show that properties of these five objects are not consistent with kilonova such as AT2017gfo. Four objects are consistent with known classes of transients such as supernovae or dwarf nova outbursts. On the other hand, the nature of the remaining one object, which shows a red color and rapid decline, remains unclear. Although later analyses of GW signal reclassified S240422ed as likely terrestrial noise, our NIR observations provide valuable lessons for future NIR surveys for GW sources. We demonstrate that deep NIR follow-up observations as presented in this work would effectively constrain the presence of red kilonova even at 200 Mpc distance. We also discuss the importance of deep and wide NIR reference images and of understanding the properties and frequency of Galactic transients.
format Preprint
id arxiv_https___arxiv_org_abs_2510_15534
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle J-GEM near-infrared follow-up observations of the gravitational wave event S240422ed
Takahashi, Ichiro
Morokuma, Tomoki
Tanaka, Masaomi
Sasada, Mahito
Akitaya, Hiroshi
Tanaka, Ichi
Tominaga, Nozomu
Yoshida, Michitoshi
Utsumi, Yousuke
Itoh, Ryosuke
Kawaguchi, Kyohei
collaboration, the J-GEM
High Energy Astrophysical Phenomena
Instrumentation and Methods for Astrophysics
We report our near-infrared (NIR) follow-up observations of the gravitational wave (GW) event S240422ed using the Subaru Telescope/MOIRCS. S240422ed was initially classified as a black hole-neutron star merger with $>$ 99% probability of electromagnetic wave emission. We started follow-up observations 7.8 hours after the event. Over two nights, we observed 206 nearby galaxies in $Y$ and $K_{\rm s}$ bands down to about 21.4 and 21.1 AB mag (3$σ$), respectively. The total completeness of our survey based on galaxy $B$-band luminosity is 22%. As a result of our observations, five candidate counterparts were identified. We show that properties of these five objects are not consistent with kilonova such as AT2017gfo. Four objects are consistent with known classes of transients such as supernovae or dwarf nova outbursts. On the other hand, the nature of the remaining one object, which shows a red color and rapid decline, remains unclear. Although later analyses of GW signal reclassified S240422ed as likely terrestrial noise, our NIR observations provide valuable lessons for future NIR surveys for GW sources. We demonstrate that deep NIR follow-up observations as presented in this work would effectively constrain the presence of red kilonova even at 200 Mpc distance. We also discuss the importance of deep and wide NIR reference images and of understanding the properties and frequency of Galactic transients.
title J-GEM near-infrared follow-up observations of the gravitational wave event S240422ed
topic High Energy Astrophysical Phenomena
Instrumentation and Methods for Astrophysics
url https://arxiv.org/abs/2510.15534