TY - JOUR
T1 - Chasing Gamma-Ray Signals from Binary Neutron Star Coalescences with the Cherenkov Telescope Array
T2 - Prospects and Observing Strategies
AU - (CTAO Consortium)
AU - Abe, S.
AU - Abhir, J.
AU - Abhishek, A.
AU - Acero, F.
AU - Acharyya, A.
AU - Adam, R.
AU - Aguasca-Cabot, A.
AU - Agudo, I.
AU - Albanese, I.
AU - Alfaro, J.
AU - Alispach, C.
AU - Alves Batista, R.
AU - Amato, E.
AU - Ambrosi, G.
AU - Ambrosino, D.
AU - Ambrosino, F.
AU - Angel, L.
AU - Aramo, C.
AU - Arbet-Engels, A.
AU - Arcaro, C.
AU - Arena, C.
AU - Arnesen, T. T.H.
AU - Asano, K.
AU - Ashkar, H.
AU - Bakshi, C.
AU - Balazs, C.
AU - Balbo, M.
AU - Baquero Larriva, A.
AU - Barbosa Martins, V.
AU - Barrio, J. A.
AU - Bartolini, C.
AU - Batković, I.
AU - Batzofin, R.
AU - Bavdaz, N.
AU - Becerra González, J.
AU - Beck, G.
AU - Benbow, W.
AU - Bernardini, E.
AU - Bernardini, M. G.
AU - Bernete, J.
AU - Berti, A.
AU - Bertucci, B.
AU - Beshley, V.
AU - Bhattacharjee, P.
AU - Bhattacharyya, S.
AU - Bigongiari, C.
AU - Biland, A.
AU - Chaty, S.
AU - Fegan, S.
AU - Horan, D.
N1 - Publisher Copyright:
© 2026. The Author(s). Published by the American Astronomical Society. Original content from this work may be used under the terms of the https://creativecommons.org/licenses/by/4.0/. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.
PY - 2026/6/10
Y1 - 2026/6/10
N2 - The detection of gravitational waves (GWs) from a binary neutron star (BNS) merger by Advanced LIGO and Advanced Virgo (GW170817), together with its electromagnetic counterpart, the short gamma-ray burst GRB 170817A, heralded the birth of multimessenger astronomy. The detection of TeV emission from GRBs motivates follow-up observations with the Cherenkov Telescope Array Observatory (CTAO), which is ideal for detecting such signals due to its unprecedented sensitivity, rapid response, and wide-field survey capabilities. The aim of this work is to evaluate GeV–TeV GW follow-up strategies for CTAO using a multistep simulation pipeline and to estimate the expected rate of joint GW–GRB detections during observing run O5. Using a simulated sample of BNS systems with corresponding GW detections, gamma-ray emission is simulated through phenomenological prescriptions based on the observed population of short GRBs, including off-axis jet scenarios. CTAO observations are simulated to account for instrument response, sky tiling strategies, integration times, and varying observing conditions. Strategies with variable and constant integration times are investigated. We find that, via an optimized follow-up strategy, about 5% of simulated GW-associated short GRBs produce GeV–TeV radiation detectable by CTAO. Detectability is strongly influenced by the jet opening angle and viewing angle, suggesting that even rough estimates of the viewing angle in GW alerts could enhance targeting. This framework motivates future follow-ups of GW-detectable events, including neutron star–black hole mergers, and further supports the development of advanced strategies incorporating galaxy distributions and synergies with future detectors such as the Einstein Telescope.
AB - The detection of gravitational waves (GWs) from a binary neutron star (BNS) merger by Advanced LIGO and Advanced Virgo (GW170817), together with its electromagnetic counterpart, the short gamma-ray burst GRB 170817A, heralded the birth of multimessenger astronomy. The detection of TeV emission from GRBs motivates follow-up observations with the Cherenkov Telescope Array Observatory (CTAO), which is ideal for detecting such signals due to its unprecedented sensitivity, rapid response, and wide-field survey capabilities. The aim of this work is to evaluate GeV–TeV GW follow-up strategies for CTAO using a multistep simulation pipeline and to estimate the expected rate of joint GW–GRB detections during observing run O5. Using a simulated sample of BNS systems with corresponding GW detections, gamma-ray emission is simulated through phenomenological prescriptions based on the observed population of short GRBs, including off-axis jet scenarios. CTAO observations are simulated to account for instrument response, sky tiling strategies, integration times, and varying observing conditions. Strategies with variable and constant integration times are investigated. We find that, via an optimized follow-up strategy, about 5% of simulated GW-associated short GRBs produce GeV–TeV radiation detectable by CTAO. Detectability is strongly influenced by the jet opening angle and viewing angle, suggesting that even rough estimates of the viewing angle in GW alerts could enhance targeting. This framework motivates future follow-ups of GW-detectable events, including neutron star–black hole mergers, and further supports the development of advanced strategies incorporating galaxy distributions and synergies with future detectors such as the Einstein Telescope.
KW - Gamma-ray bursts (629)
KW - Gamma-ray telescopes (634)
KW - Gamma-ray transient sources (1853)
KW - Gravitational wave astronomy (675)
KW - Gravitational wave sources (677)
KW - High energy astrophysics (739)
UR - https://www.scopus.com/pages/publications/105040957666
U2 - 10.3847/1538-4357/ae658c
DO - 10.3847/1538-4357/ae658c
M3 - Article
AN - SCOPUS:105040957666
SN - 0004-637X
VL - 1004
JO - Astrophysical Journal
JF - Astrophysical Journal
IS - 1
M1 - 46
ER -