//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 10863 SUBJECT: GRB 100619A: Swift detection of a burst DATE: 10/06/19 00:37:25 GMT FROM: David Palmer at LANL J. K. Cannizzo (NASA/UMBC), N. Gehrels (NASA/GSFC), J. M. Gelbord (PSU), S. T. Holland (CRESST/USRA/GSFC), J. Mao (INAF-OAB), R. Margutti (INAF-OAB), F. E. Marshall (NASA/GSFC), D. M. Palmer (LANL), B. Sbarufatti (INAF-OAB/IASFPA), M. H. Siegel (PSU), M. A. Stark (PSU) and T. N. Ukwatta (GSFC/GWU) report on behalf of the Swift Team: At 00:21:07 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 100619A (trigger=424998). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 84.615, -27.001 which is RA(J2000) = 05h 38m 28s Dec(J2000) = -27d 00' 02" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed two well-separated peaks about 90 seconds apart with an overall duration of about 120 sec. The peak count rate was ~4000 counts/sec (15-350 keV), at ~0 sec after the trigger for the first peak, and 5000 counts/sec (15-350 keV) at ~95 sec after the trigger for the second peak. The XRT began observing the field at 00:22:23.7 UT, 76.4 seconds after the BAT trigger. Using promptly downlinked data we find a bright, fading, uncatalogued X-ray source with an enhanced position: RA, Dec 84.6227, -27.0049 which is equivalent to: RA(J2000) = 05h 38m 29.46s Dec(J2000) = -27d 00' 17.8" with an uncertainty of 2.1 arcseconds (radius, 90% containment). This location is 27 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 http://www.swift.ac.uk/sper. A power-law fit to a spectrum formed from promptly downlinked event data gives a column density in excess of the Galactic value (2e+20 cm^-2, Kalberla et al. 2005), with an excess column of 3.8 (+1.95/-1.69) x 10^21 cm^-2 (90% confidence). The initial flux in the 0.1 s image was 5.61e-08 erg cm^-2 s^-1 (0.2-10 keV). UVOT took a finding chart exposure of 150 seconds with the White filter starting 87 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 0.03. Burst Advocate for this burst is J. K. Cannizzo (cannizzo AT milkyway.gsfc.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/too.html.) //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 10864 SUBJECT: GRB 100619A: Swift-BAT refined analysis DATE: 10/06/19 10:12:10 GMT FROM: Scott Barthelmy at NASA/GSFC M. Stamatikos (GSFC/ORAU), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. K. Cannizzo (NASA/UMBC), J. R. Cummings (GSFC/UMBC), E. E. Fenimore (LANL), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC/UMD), D. M. Palmer (LANL), A. M. Parsons (GSFC), T. Sakamoto (GSFC/UMBC), G. Sato (ISAS), J. Tueller (GSFC), T. N. Ukwatta (GWU) (i.e. the Swift-BAT team): Using the data set from T-239 to T+963 sec from recent telemetry downlinks, we report further analysis of BAT GRB 100619A (trigger #424998) (Cannizzo, et al., GCN Circ. 10863). The BAT ground-calculated position is RA, Dec = 84.618, -27.012 deg which is RA(J2000) = 05h 38m 28.3s Dec(J2000) = -27d 00' 42.2" with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment). The partial coding was 75%. The mask-weighted light curve shows two well separated peaks. The first s compsed of several overlapping pulses which starts at ~T-3 sec, peaks at ~T_10 sec, and returns to background at ~T+20 sec. The second peak starts ~T+55 sec, peaks at ~T=85 sec, and ends at ~T+120 sec. T90 (15-350 keV) is 97.5 +- 3 sec (estimated error including systematics). The time-averaged spectrum from T-2.9 to T+105.7 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.83 +- 0.06. The fluence in the 15-150 keV band is 4.5 +- 0.1 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T+87.22 sec in the 15-150 keV band is 4.8 +- 0.2 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/424998/BA/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 10865 SUBJECT: GRB 100619A: Enhanced Swift-XRT position DATE: 10/06/19 10:14:39 GMT FROM: Phil Evans at U of Leicester A.P. Beardmore, P.A. Evans, M.R. Goad and J.P. Osborne (U. Leicester) report on behalf of the Swift-XRT team. Using 4927 s of XRT Photon Counting mode data and 8 UVOT images for GRB 100619A, 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 = 84.62214, -27.00534 which is equivalent to: RA (J2000): 05h 38m 29.31s Dec (J2000): -27d 00' 19.2" with an uncertainty of 1.5 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: 10866 SUBJECT: GRB 100619A: Swift-XRT refind analysis DATE: 10/06/19 12:07:18 GMT FROM: Jirong Mao at INAF-OAB J. Mao (INAF-OAB) and J. K. Cannizzo (NASA/UMBC) report on behalf of the Swift-XRT team: We have analysed 6.6 ks of XRT data for GRB 100619A (Cannizzo et al. GCN Circ. 10863), from 80 s to 13.2 ks after the BAT trigger. The data comprise 492 s in Windowed Timing (WT) mode with the remainder in Photon Counting (PC) mode. The light curve initially shows a flare feature at the time 90s, then it has a power-law decay with an index 0.88, after that, the light curve shows a clear flare feature with the peak at 1000s. Then, the light cure has a power-law decay with an index of alpha=0.85 (+/-0.02). A spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 1.41 (+/-0.03). The best-fitting absorption column is 3.4 (+/-0.1) x 1021 cm^-2, in excess of the Galactic value of 2.0 x 1020 cm^-2 (Kalberla et al. 2005). The PC mode spectrum has a photon index of 2.16 (+0.20, -0.19) and a best-fitting absorption column of 3.7 (+/-0.6) x 1021 cm^-2. The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 6.7 x 10^-11 (9.6 x 10^-11) erg cm^-2 count^-1. If the light curve continues to decay with a power-law decay index of 0.85, the count rate at T+24 hours will be 0.015 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.0 x 10^-12 (1.4 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/00424998. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 10867 SUBJECT: GRB 100619A: Swift/UVOT Upper Limits DATE: 10/06/19 13:15:56 GMT FROM: Peter Curran at MSSL P.A. Curran (MSSL-UCL) and J. K. Cannizzo (NASA/UMBC) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 100619A 87 s after the BAT trigger (Cannizzo et al., GCN Circ. 10863). No optical afterglow consistent with the enhanced XRT position (Beardmore et al., GCN Circ. 10865) is detected in the initial UVOT exposures. Preliminary 3-sigma upper limits using the UVOT photometric system (Poole et al. 2008, MNRAS, 383, 627) for the first finding chart (FC) and subsequent exposures are: Filter T_start(s) T_stop(s) Exp(s) Mag ----------------------------------------------- white 87 237 147 >21.2 (FC) u 300 549 246 >20.5 (FC) white 87 6773 785 >22.0 v 630 7184 510 >20.2 b 556 13220 1161 >21.5 u 300 19002 2089 >21.6 w1 679 18300 2128 >21.7 m2 654 17394 1396 >21.4 w2 606 6978 510 >20.9 The values quoted above are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.03 in the direction of the burst (Schlegel et al. 1998). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 10868 SUBJECT: GRB 100619A: Fermi GBM detection DATE: 10/06/20 14:52:19 GMT FROM: Narayana Bhat at U Alabama/Huntsville/GBM P. N. Bhat (UAH) reports on behalf of the Fermi GBM Team: "At 03:55:23.71 UT on 19 June 2010, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 100619A (trigger 298612525 / 100619015). which was also detected by the SWIFT-BAT (Cannizzo et al. 2008, GCN 10863) The GBM on-ground location is consistent with the Swift position. The angle from the Fermi LAT boresight is 117 degrees. The GBM light curve shows 2 well separated pulses with a duration (T90) of about 96.8 s (50-300 keV). The time-averaged spectrum from T0-9.216 s to T0+101.378 s is well fit by a power law function with an exponential high energy cutoff. The power law index is -1.61 +/- 0.05 and the cutoff energy, parameterized as Epeak, is 143.2 +/- 24.8 keV (C-stat 419 for 241 d.o.f.). The event fluence (8-1000 keV) in this time interval is (1.71 +/- 0.1)E-05 erg/cm^2. The 1-sec peak photon flux measured starting from T0+83 s in the 10-1000 keV band is 1.88 +/- 0.04 ph/s/cm^2. A Band function fits the spectrum equally well (C-stat 419 for 240 d.o.f.) with Epeak= 135.3 +/- 37.1 keV, alpha = -1.60 +/- 0.07 and beta = -2.36 +/- 0.69. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog." //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 10879 SUBJECT: GRB 100619A: Correction to the Fermi GBM trigger time DATE: 10/06/21 18:37:43 GMT FROM: Narayana Bhat at U Alabama/Huntsville/GBM P. N. Bhat (UAH) reports on behalf of the Fermi GBM Team: "The trigger time of GRB 100619A reported in GCN 10868 as 03:55:23.71 UT is in error. The actual trigger time is 00:21:07.03 UT."