[vsnet-grb-info 24795] GRB 200125A: Further Swift-XRT observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  26894
SUBJECT: GRB 200125A: Further Swift-XRT observations
DATE:    20/01/27 08:39:42 GMT
FROM:    Phil Evans at U of Leicester  <pae9 at leicester.ac.uk>

P.A. Evans, K.L. Page (U. Leicester) and A.Y. Lien (GSFC/UMBC) report on behalf of the Swift-XRT team:

We provide an update on the XRT light curve evolution of GRB 200125A (GCN Circs. 26876 and 26885). 

The XRT light curve shows early, strong flaring activity which is interrupted at T0+414 s as the GRB went into Earth eclipse; by the time of the next observation (T0+3.8 ks) the light curve had faded by 4 orders of magnitude to ~0.1 ct/sec (2e-12 erg cm^-2 s^-1; 0.3-10 keV). It has remained approximately at this level, with some small variation, until our most recent data point at T0+113 ks (=T0+1.3 d). This suggests a very long-lived ‘plateau’ phase. Such long-duration plateaux are rare but not unique. Due to the expectation of a break at some, unknown point in the (probably) near future, we are unable to predict what the flux will be over the coming days. Observations are ongoing. The latest results can be viewed via: https://www.swift.ac.uk/xrt_products/00952164/

This circular is an official product of the Swift-XRT team.