GCN Circular 33723
Subject
GRB 230430A: A short GRB from a neutron star merger
Date
2023-05-04T08:30:05Z (a year ago)
From
Remo Ruffini at ICRA <ruffini@icra.it>
R. Ruffini, Y. Aimuratov, L. Becerra, C.L. Bianco, C. Cherubini, S. Filippi, M. Karlica, Liang Li, R. Moradi, F. Rastegar Nia, J.A. Rueda, N. Sahakyan, Y. Wang, S.S. Xue, on behalf of the ICRANet team, report:
GRB 230430A appears to have strong similarities with GRB 090510 originating from merging binary neutron stars (Ruffini et al., 2016). Also in this case no supernova is expected. Attention should be given to the determination of the temporal slope of the late X-ray luminosity which for long GRBs coincide with the common value of the power-law index -1.48+/-0.32 of the afterglow, and for short GRBs appears to have a different power law, to be confirmed (see Fig. 5 in Ruffini et al., 2016). The GeV luminosity for long GRBs has a temporal power-law index -1.19+/-0.04 and for short GRBs it has a temporal power-law index -1.29+/-0.06 (Ruffini et al., 2021). Confirmation of the values of both slopes in GRB 230430A is highly recommended to differentiate short GRBs from long GRBs. We encourage monitoring for the possible appearance of a kilonova signal.
References:
Ruffini, R.; Muccino, M.; Aimuratov, Y.; et al.; ApJ, 831 (2016) 178.
Ruffini, R.; Moradi, R.; Rueda, J.A; et al.; MNRAS, 504 (2021) 5301.