Title
GRB 240825A: The nature of the afterglow motivates the search of the associated supernova
Date Issued
2024
Author(s)
Ruffini, R.
Bianco, C. L.
Li, Liang
Mirtorabi, M. T.
Moradi, R.
Rastegar Nia, F.
Rueda, J. A.
Wang, Y.
Icranet Team
Abstract
The T90 of GRB 240825A is only 4 seconds (GCN 37301), and it is located at a relatively close distance (z=0.659, GCN 37293). The fluence reaches a high level of 10^{-4} erg/cm^2. Through spectral analysis, we find that peak energy Ep is about 400 keV and isotropic energy Eiso is about 2x10^{53} erg, consistent with the Amati relation for long-duration gamma-ray bursts. Comparing its X-ray afterglow (see figure attached below, blue dots), its luminosity falls within the range of other long-duration bursts which are associated with supernovae, higher than those of short-duration bursts which have merge origins. Based on these findings, we conclude that GRB 240825A is a long-duration burst (BdHN I; see, e.g., Bianco, et al., 2024, ApJ, 966, 219) and is associated with a SN. The supernova may reach its optical peak in the observer's rest-frame approximately one month after the trigger. Its peak brightness should be within the detection limits of both ground- and space-based telescopes. Therefore, we encourage further observations in the coming weeks. Figure: https://www.icranet.org/documents/GRB_240825A.png