[vsnet-grb-info 15524] GRB 140903A: Chandra detection of the afterglow

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  16813
SUBJECT: GRB 140903A: Chandra detection of the afterglow
DATE:    14/09/10 21:26:39 GMT
FROM:    Takanori Sakamoto at AGU  <tsakamoto at phys.aoyama.ac.jp>

T. Sakamoto (AGU), E. Troja (GSFC/UMCP), N. Gehrels (GSFC), 
J. Norris (BSU), S. D. Barthelmy (GSFC), J. L. Racusin (GSFC), 
N. Kawai (Tokyo Tech), A. Fruchter (STScI)

A Chandra ToO observation of a short GRB 140903A (Cummings et al., GCN Circ. 16763; 
Cummings et al., GCN Circ. 16765) started on September 6 08:54 UT (~2.7 days after the 
GRB trigger) for a total of 19.8 ksec.  The X-ray afterglow was clearly detected at 
a position (RA, Dec) = (238.013519, +27.60303) which is equivalent to:

RA (J2000) = 15 52 03.24
Dec (J2000) = +27 36 10.9

The 1-sigma statistical error is 0.05 and 0.04 arcsec on RA and Dec respectively.  
The systematic error of the Chandra aspect solution is 0.3 arcsec (radius, 68% 
containment; i.e, http://cxc.harvard.edu/cal/ASPECT/celmon/) which dominates  
the localization uncertainty. 

The Chandra location is consistent with the enhanced XRT position (De Pasquale et al., 
GCN Circ. 16767) and the reported NIR, optical and radio afterglow/host candidate 
(Capone et al., GCN Circ. 16769; Cenko et al., GCN Circ. 16785; Cenko et al., 
GCN Circ. 16770; Fruchter et al., GCN Circ. 16776; Fong, GCN Circ. 16777; 
Dichiara et al., GCN Circ. 16781; Xu et al. GCN Circ. 16783; Levan et al. GCN Circ. 16784).  
Our Chandra detection confirms the association of the reported NIR, optical and radio 
candidate to GRB 140903A.  Further Chandra observations are planned.  

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