//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 19547 SUBJECT: GRB 160622A: Swift detection of a possible short GRB or a new SGR DATE: 16/06/22 02:38:47 GMT FROM: Caryl Gronwall at PSU/Swift-UVOT A. D'Ai (INAF-IASFPA), N. Gehrels (NASA/GSFC), C. Gronwall (PSU), J. A. Kennea (PSU), A. Y. Lien (GSFC/UMBC), F. E. Marshall (NASA/GSFC), A. Maselli (INAF-IASFPA), T. Sakamoto (AGU) and M. H. Siegel (PSU) report on behalf of the Swift Team: At 02:03:13 UT, the Swift Burst Alert Telescope (BAT) triggered and located possible GRB 160622A (trigger=700791). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 244.373, -51.045 which is RA(J2000) = 16h 17m 30s Dec(J2000) = -51d 02' 41" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a short pulse with a duration of about 0.1 sec. The peak count rate was ~4000 counts/sec (15-350 keV), at ~0 sec after the trigger. The XRT began observing the field at 02:04:44.8 UT, 91.1 seconds after the BAT trigger. No source was detected in the 2.5-s promptly available image. We are waiting for the full dataset to detect and localise the XRT counterpart. UVOT took a finding chart exposure of 3 seconds with the White filter starting 95 seconds after the BAT trigger. No credible afterglow candidate has been found in the initial data products. The 2.7'x2.7' sub-image covers 25% of the BAT error circle. Because of the density of catalogued stars, further analysis is required to report an upper limit for any afterglow in the sub-image. Results from the list of sources generated on-board are not available at this time. No correction has been made for the large, but uncertain extinction expected. This source is at a low galactic latitude of -0.37 degrees and may be an SGR. While the BAT lightcurve looks like a short GRB, it is not dissimilar from an SGR. We need the full dataset to determine the nature of this trigger. Burst Advocate for this burst is A. D'Ai (antonino.dai AT ifc.inaf.it). Please contact the BA by email if you require additional information regarding Swift followup of this burst. In extremely urgent cases, after trying the Burst Advocate, you can contact the Swift PI by phone (see Swift TOO web site for information: http://www.swift.psu.edu/too.html.) //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 19548 SUBJECT: BAT trigger 700791 (possible GRB 160622A) is SNR RCW 103 DATE: 16/06/22 14:20:36 GMT FROM: Phil Evans at U of Leicester A. D'Ai(INAF-IASFPA), P.Evans (U. Leicester), N. Gehrels (NASA/GSFC), C. Gronwall (PSU), J. A. Kennea (PSU), A. Y. Lien (GSFC/UMBC), F. E. Marshall (NASA/GSFC), A. Maselli (INAF-IASFPA), T. Sakamoto (AGU) and M. H. Siegel (PSU) report on behalf of the Swift Team: Swift has gathered 5.8 ks of WT mode data and 463 s of PC mode data on the field of the BAT trigger 700791 (= possible GRB 160622A, GCN 19547). The XRT image is dominated by diffuse emission from the supernova remnant RCW 103 (Frank et al., ApJ, 2015, 810,113), with a bright central source at RA,Dec. = 244.40282, -51.03916, which is equivalent to: RA (J2000.0) = 16h 17m 36.68s Dec (J2000.0) = -51d 02' 21.0" with an uncertainty of 3.5" (radius, 90% confidence). This is consistent with the catalogued X-ray source 3XMM J161736.1-510224. Analysis is complicated by the presence of the diffuse emission from the SNR, however the source count rate is ~2 ct/sec, with a flux of approximately 9.1 (+2.0, -1.6) × 10^-11 erg cm^-2 s^-1 (derived from a power-law spectrum with NH=7.0 (+3.6, -2.5)e21 cm^-2, and a photon index of 2.2 (+/- 0.4). This is substantially above the 3XMM count rate of 2.567 (+/- 0.020)e-12 erg cm^-2 s^-1. Observations and analysis are ongoing. This circular is an official product of the Swift XRT team. [GCN OPS NOTE(22jun16): Per author's request, A.D'A's name was corrected, and the missing minus sign for the sexagesimal form of the Dec value was added.] //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 19557 SUBJECT: GROND observations of GRB 160622A/SNR RCW 103/SGR 1617-5103 DATE: 16/06/23 19:42:07 GMT FROM: Alexander Kann at TLS Tautenburg D. A. Kann (TLS Tautenburg), P. Schady, and J. Greiner (both MPE Garching) report on behalf of the GROND team. We observed the field of GRB 160622A/SNR RCW 103/SGR 1617-5103 (Swift trigger 700791; D'Ai et al., GCN #19547) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008, PASP 120, 405) mounted at the 2.2 m MPG telescope at ESO La Silla Observatory (Chile). Observations started at 02:19 UT, 0.26 hrs after the GRB trigger, and continued for around 1 hr. They were performed at an average seeing of 1".4 and at an average airmass of 1. In stacked data amounting to about 30 min exposure time in g'r'i'z' and about 15 min in JHK, we do not detect any sources within the enhanced Swift-XRT error circle (Evans et al., GCN #19551) down to the following 3 sigma upper limits (AB magnitudes): g´ > 23.4 mag, r' > 23.3 mag, i' > 23.1 mag, z' > 23.0 mag, J > 19.8 mag, H > 18.9 mag, and K > 18.7 mag. We detect two sources just outside the XRT error circle. One to the south, which is likely a blended double source, and a faint source to the west. The PSF wing of the southern source lies within the XRT error circle, reducing our limiting magnitude there. Given magnitudes are calibrated against GROND zeropoints as well as 2MASS field stars and are not corrected for the very high expected Galactic foreground extinction in the direction of the burst (Schlafly & Finkbeiner, 2011).