[vsnet-grb-info 25118] GRB 200219A: Chandra rapid ToO upper limit

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  27218
SUBJECT: GRB 200219A: Chandra rapid ToO upper limit
DATE:    20/02/26 06:32:01 GMT
FROM:    Takanori Sakamoto at AGU  <tsakamoto at phys.aoyama.ac.jp>

T. Sakamoto (AGU), E. Troja (NASA/GSFC/ORAU), J. Norris (BSU),
S. D. Barthelmy (GSFC), J. L. Racusin (GSFC), N. Kawai (Tokyo Tech),
A. Fruchter (STScI), M. Im (SNU)

A Chandra ToO observation of GRB 200219A (Lien et al., GCN Circ. 27125;
Bissaldi et al., GCN Circ. 27137) started on February 23 16:32 UT (~4.4 days
after the GRB trigger) for a total of 19.2 ksec.

We do not detect an X-ray afterglow at the location of the enhanced XRT position
(Osborne et al., GCN Circ. 27138).  The calculated 3-sigma upper limit is 3.3e-4 c/s
in the 0.35-8 keV band using aprates of the CIAO software package.
Using the best fit spectral parameters of the XRT PC mode data, we estimated
an 3-sigma unabsorbed flux upper limit of 5.0e-15 erg/cm2/s in the 0.35-8 keV band.

We would like to thank the Chandra operation team for rapidly approving and
making this observation.