//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 28088 SUBJECT: GRB 200713A: Swift detection of a burst DATE: 20/07/13 12:05:03 GMT FROM: Scott Barthelmy at NASA/GSFC A. Y. Lien (GSFC/UMBC), E. Ambrosi (INAF-IASFPA), S. D. Barthelmy (GSFC), V. D'Elia (SSDC), J.D. Gropp (PSU), N. J. Klingler (PSU), S. Laha (GSFC/UMBC/CRESST), K. L. Page (U Leicester) and A. Tohuvavohu (U Toronto) report on behalf of the Neil Gehrels Swift Observatory Team: At 11:42:54 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 200713A (trigger=982201). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 76.962, -32.825, which is RA(J2000) = 05h 07m 51s Dec(J2000) = -32d 49' 30" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). As is the usual for image triggers, the light curve does not show anything. The XRT began observing the field at 11:45:24.7 UT, 150.1 seconds after the BAT trigger. Using promptly downlinked data we find a bright, fading, uncatalogued X-ray source with an enhanced position: RA, Dec 76.9492, -32.8144 which is equivalent to: RA(J2000) = 05h 07m 47.81s Dec(J2000) = -32d 48' 51.7" with an uncertainty of 2.7 arcseconds (radius, 90% containment). This location is 54 arcseconds from the BAT onboard position, within the BAT error circle. This position may be improved as more data are received; the latest position is available at https://www.swift.ac.uk/sper. A power-law fit to a spectrum formed from promptly downlinked event data gives a column density consistent with the Galactic value of 1.99 x 10^20 cm^-2 (Willingale et al. 2013). The initial flux in the 2.5 s image was 1.27e-09 erg cm^-2 s^-1 (0.2-10 keV). UVOT took a finding chart exposure of 150 seconds with the White filter starting 159 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 100% of the XRT error circle. The typical 3-sigma upper limit has been about 19.6 mag. The 8'x8' region for the list of sources generated on-board covers 100% of the XRT error circle. The list of sources is typically complete to about 18 mag. No correction has been made for the expected extinction corresponding to E(B-V) of 0.02. Burst Advocate for this burst is A. Y. Lien (amy.y.lien AT nasa.gov). 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/) //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 28089 SUBJECT: GRB 200713A: Enhanced Swift-XRT position DATE: 20/07/13 16:12:16 GMT FROM: Phil Evans at U of Leicester P.A. Evans, M.R. Goad, J.P. Osborne and A.P. Beardmore (U. Leicester) report on behalf of the Swift-XRT team. Using 208 s of XRT Photon Counting mode data and 1 UVOT images for GRB 200713A, we find an astrometrically corrected X-ray position (using the XRT-UVOT alignment and matching UVOT field sources to the USNO-B1 catalogue): RA, Dec = 76.94990, -32.81475 which is equivalent to: RA (J2000): 05h 07m 47.98s Dec (J2000): -32d 48' 53.1" with an uncertainty of 2.1 arcsec (radius, 90% confidence). This position may be improved as more data are received. The latest position can be viewed at http://www.swift.ac.uk/xrt_positions. Position enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans et al. (2009, MNRAS, 397, 1177). This circular was automatically generated, and is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 28092 SUBJECT: GRB 200713A: Swift-XRT refined Analysis DATE: 20/07/14 06:59:31 GMT FROM: Phil Evans at U of Leicester M. Perri (ASDC), V. D'Elia (ASDC), A. D'Ai (INAF-IASFPA), A. Tohuvavohu (U. Toronto), B. Sbarufatti (PSU), D.N. Burrows (PSU), K.L. Page (U. Leicester), A.P. Beardmore (U. Leicester), P.A. Evans (U. Leicester) and A.Y. Lien report on behalf of the Swift-XRT team: We have analysed 6.2 ks of XRT data for GRB 200713A (Lien et al. GCN Circ. 28088), from 156 s to 62.7 ks after the BAT trigger. The data comprise 128 s in Windowed Timing (WT) mode with the remainder in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Evans et al. (GCN Circ. 28089). The light curve can be modelled with an initial power-law decay with an index of alpha=5.1 (+/-0.3), followed by a break at T+358 s to an alpha of 0.41 (+0.04, -0.05). A spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 3.71 (+0.26, -0.24). The best-fitting absorption column is 3.2 (+/-0.5) x 10^21 cm^-2, in excess of the Galactic value of 2.0 x 10^20 cm^-2 (Willingale et al. 2013). The PC mode spectrum has a photon index of 2.13 (+0.18, -0.17) and a best-fitting absorption column of 1.7 (+/-0.5) x 10^21 cm^-2. The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 3.2 x 10^-11 (4.5 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 1.7 (+/-0.5) x 10^21 cm^-2 Galactic foreground: 2.0 x 10^20 cm^-2 Excess significance: 5.0 sigma Photon index: 2.13 (+0.18, -0.17) If the light curve continues to decay with a power-law decay index of 0.41, the count rate at T+24 hours will be 0.059 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.9 x 10^-12 (2.7 x 10^-12) erg cm^-2 s^-1. The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00982201. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 28096 SUBJECT: GRB 200713A: Swift-BAT refined analysis DATE: 20/07/14 16:02:02 GMT FROM: Amy Lien at GSFC T. N. Ukwatta (LANL), S. D. Barthelmy (GSFC), J. R. Cummings (CPI), H. A. Krimm (NSF), S. Laha (GSFC/UMBC), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (AGU), M. Stamatikos (OSU) (i.e. the Swift-BAT team): Using the data set from T-100 to T+963 sec from the recent telemetry downlink, we report further analysis of BAT GRB 200713A (trigger #982201) (Lien et al., GCN Circ. 28088). The BAT ground-calculated position is RA, Dec = 76.941, -32.846 deg which is RA(J2000) = 05h 07m 45.8s Dec(J2000) = -32d 50' 47.1" with an uncertainty of 2.8 arcmin, (radius, sys+stat, 90% containment). The partial coding was 46%. The mask-weighted light curve shows several weak overlapping pulses that start at ~T+20 s and end at ~T+80 s. T90 (15-350 keV) is 48.98 +- 9.52 sec (estimated error including systematics). The time-averaged spectrum from T+18.45 to T+74.94 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 2.48 +- 0.32. The fluence in the 15-150 keV band is 9.0 +- 1.6 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from T+49.94 sec in the 15-150 keV band is 0.8 +- 0.3 ph/cm2/sec. All the quoted errors are at the 90% confidence level. The results of the batgrbproduct analysis are available at http://gcn.gsfc.nasa.gov/notices_s/982201/BA/