GCN Circular 25581
Subject
GRB 190829A: Follow up VLA and VLBI radio observations urged
Date
2019-08-30T20:21:02Z (5 years ago)
From
Arnon Dar at Technion-Israel Inst. of Tech <arnon@physics.technion.ac.il>
S. Dado and A. Dar report,
The long duration, low luminosity GRB190829A [1] at redshift z=0.0785 [2]
with Ep=130 +/- 20 keV and Eiso~1.8E50 erg, most probably, is an ordinary
narrowly beamed GRB being viewed from far off-axis -it satisfies well the
correlation (1+z)Ep propto (Eiso)^{1/3}, predicted [3] by the cannonball
model of GRBs, as can be seen from figure 3 of [4]. Like in SHB 170817A
[5], VLA and VLBI follow up observations of the radio afterglow of
GRB190829A may resolve its compact superluminal source and measure its
apparent superluminal velocity, Vapp ~ 2c/theta, from which its far
off-axis viewing angle theta can be determined [6]. We urge such follow
up VLA and VLBI radio observations of its afterglow.
[1] S. Lesage et al., GCN 25575.
[2] A. F. Valeev et al., GCN 25565.
[3] A. Dar & A. De R'ujula, arXiv:astro-ph/0012227 (Eq. 40).
[4] S. Dado & A. Dar, arxiv:1908.05116.
[5] K. P. Mooley, et al., Nature, 561, 355 (2018) [arXiv:1806.09693].
[6] A. Dar & A. De R'ujula, arXiv:astro-ph/0008474.