{
  "bibcode": "2021GCN.30879....1S",
  "body": "T. Sakamoto (AGU), E. Troja (NASA/GSFC/ORAU), J. Norris (BSU),\nS. D. Barthelmy (GSFC), J. L. Racusin (GSFC), N. Kawai (Tokyo Tech),\nA. Fruchter (STScI), M. Im (SNU), B. Cenko (GSFC)\n\nA Chandra ToO observation of a short GRB 200919A (Tohuvavohu et al., GCN Circ. 30846)\nstarted on February 21 02:54 UT (~2.1 days after the GRB trigger) for a total of 19.8 ksec.\n\nWe do not detect an X-ray afterglow at the location of the enhanced XRT position\n(Goad et al., GCN Circ. 30850).  The calculated 3-sigma upper limit is 3.4 x 10^-4 c/s\nin the 0.3-8 keV band using aprates of the CIAO software package.  Assuming N_H of\n1.5 x 10^21 cm^-2 and photon index of 2, we estimated an 3-sigma unabsorbed flux\nupper limit of 6.9 x 10^-15 erg/cm2/s in the 0.3-8 keV band.\n\nWe would like to thank Patrick Slane, Harvey Tananbaum, Andrea Prestwich,\nand the Chandra operation team for rapidly approving and making this observation.",
  "circularId": 30879,
  "createdOn": 1632533221000,
  "email": "tsakamoto@phys.aoyama.ac.jp",
  "subject": "GRB 210919A: Chandra rapid ToO upper limit",
  "submitter": "Takanori Sakamoto at AGU  <tsakamoto@phys.aoyama.ac.jp>",
  "eventId": "GRB 210919A"
}