DOI

https://doi.org/10.48717/0j0n-te42

Project

EG138

Title

phs.ref check GRB260310A

Abstract

The recently launched Einstein Probe mission will enable access to a new region of the parameter space for the study of gamma-ray bursts (GRB). In particular, its soft energy range and follow-up capabilities should enhance the number of low-luminosity, low-redshift GRBs with a well localised afterglow. As the experience of 030329, 170817A, and 221009A has successfully demonstrated, z<0.2 events can uniquely benefit from multi-epoch high-angular-resolution observations. In the present proposal, we request observations of one event detected by Einstein Probe at z<0.2, with a confirmed radio detection and well observable with the EVN (dec>0deg). We request a short 1-hr run to assess phase reference sources, and two 10-hr long 5-GHz integrations in e-VLBI mode (the second one conditional on a detection in the first). These observations will be able to reveal expansions/displacements of the radio afterglow, which are fundamental in disentangling the physical conditions of the jet and the ambient medium (eg, energetics, velocity structure, density profile).