//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 24993 SUBJECT: GRB 190706B: Swift detection of a burst DATE: 19/07/06 12:53:10 GMT FROM: Scott Barthelmy at NASA/GSFC A. Tohuvavohu (PSU), S. D. Barthelmy (GSFC), J.D. Gropp (PSU), F. E. Marshall (NASA/GSFC), D. M. Palmer (LANL), B. Sbarufatti (PSU) and M. H. Siegel (PSU) report on behalf of the Neil Gehrels Swift Observatory Team: At 12:40:50 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 190706B (trigger=913302). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 107.449, -29.584, which is RA(J2000) = 07h 09m 48s Dec(J2000) = -29d 35' 02" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve shows a few peaks with a total duration of about 25 sec. The peak count rate was ~1100 counts/sec (15-350 keV), at ~0 sec after the trigger. The XRT began observing the field at 12:42:24.4 UT, 94.4 seconds after the BAT trigger. Using promptly downlinked data we find an uncatalogued X-ray source located at RA, Dec 107.46161, -29.55341 which is equivalent to: RA(J2000) = 07h 09m 50.79s Dec(J2000) = -29d 33' 12.3" with an uncertainty of 3.6 arcseconds (radius, 90% containment). This location is 116 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. We cannot determine whether the source is fading at the present time. A power-law fit to a spectrum formed from promptly downlinked event data gives a column density consistent with the Galactic value of 2.40 x 10^21 cm^-2 (Willingale et al. 2013). UVOT took a finding chart exposure of 150 seconds with the White filter starting 100 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 none of the XRT error circle. 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 0.15. Burst Advocate for this burst is A. Tohuvavohu (aaronb AT swift.psu.edu). 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: 24994 SUBJECT: GRB 190706B: Prompt enhanced Swift-XRT position DATE: 19/07/06 13:23:56 GMT FROM: Phil Evans at U of Leicester P.A. Evans (U. Leicester) reports on behalf of the Swift-XRT team: Using promptly downlinked XRT event data for GRB 190706B, we find an enhanced XRT position of the afterglow: RA, Dec: 107.4616, -29.5525 which is equivalent to: RA (J2000) = 07 09 50.78 Dec (J2000) = -29 33 09.1 with an uncertainty of 2.0 arcseconds (radius, 90% confidence). Analysis of the promptly available data is online at http://www.swift.ac.uk/sper/913302. Position enhancement is is described by Goad et al. (2007, A&A, 476, 1401) and Evans et al. (2009, MNRAS, 397, 1177). This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 24995 SUBJECT: GRB 190706B: Enhanced Swift-XRT position DATE: 19/07/06 15:30:08 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 1466 s of XRT Photon Counting mode data and 2 UVOT images for GRB 190706B, 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 = 107.46211, -29.55293 which is equivalent to: RA (J2000): 07h 09m 50.91s Dec (J2000): -29d 33' 10.5" with an uncertainty of 1.8 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: 24999 SUBJECT: GRB 190706B: Swift-XRT refined Analysis DATE: 19/07/06 23:11:12 GMT FROM: Phil Evans at U of Leicester V. D'Elia (ASDC), J. D. Gropp (PSU), J.A. Kennea (PSU), A.P. Beardmore (U. Leicester), P.A. Evans (U. Leicester), J.P. Osborne (U. Leicester), A. D'Ai (INAF-IASFPA), A. Melandri (INAF-OAB) and A. Tohuvavohu report on behalf of the Swift-XRT team: We have analysed 8.5 ks of XRT data for GRB 190706B (Tohuvavohu et al. GCN Circ. 24993), from 98 s to 29.4 ks after the BAT trigger. The data comprise 26 s in Windowed Timing (WT) mode with the remainder in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Beardmore et al. (GCN Circ. 24994). The light curve can be modelled with a power-law decay with a decay index of alpha=0.80 (+0.08, -0.07). A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 1.94 (+0.23, -0.22). The best-fitting absorption column is 3.1 (+1.0, -0.7) x 10^21 cm^-2, consistent with the Galactic value of 2.4 x 10^21 cm^-2 (Willingale et al. 2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 3.9 x 10^-11 (5.5 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 3.1 (+1.0, -0.7) x 10^21 cm^-2 Galactic foreground: 2.4 x 10^21 cm^-2 Excess significance: <1.6 sigma Photon index: 1.94 (+0.23, -0.22) If the light curve continues to decay with a power-law decay index of 0.80, the count rate at T+24 hours will be 5.0 x 10^-3 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.9 x 10^-13 (2.8 x 10^-13) erg cm^-2 s^-1. The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00913302. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25003 SUBJECT: GRB 190706B: Swift-BAT refined analysis DATE: 19/07/07 02:03:38 GMT FROM: Amy Lien at GSFC C. B. Markwardt (GSFC), S. D. Barthelmy (GSFC), J. R. Cummings (CPI), H. A. Krimm (NSF), A. Y. Lien (GSFC/UMBC), D. M. Palmer (LANL), T. Sakamoto (AGU), M. Stamatikos (OSU), A. Tohuvavohu (PSU), T. N. Ukwatta (LANL) (i.e. the Swift-BAT team): Using the data set from T-239 to T+963 sec from the recent telemetry downlink, we report further analysis of BAT GRB 190706B (trigger #913302) (Tohuvavohu et al., GCN Circ. 24993). The BAT ground-calculated position is RA, Dec = 107.443, -29.575 deg which is RA(J2000) = 07h 09m 46.4s Dec(J2000) = -29d 34' 30.7" with an uncertainty of 2.2 arcmin, (radius, sys+stat, 90% containment). The partial coding was 69%. The mask-weighted light curve shows a multi-peaked structure that starts at ~T0 and ends at ~T+30 s. The highest peak occurs at ~T+1 s. T90 (15-350 keV) is 25.16 +- 6.35 sec (estimated error including systematics). The time-averaged spectrum from T-0.25 to T+27.48 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.90 +- 0.23. The fluence in the 15-150 keV band is 5.8 +- 0.9 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from T+0.10 sec in the 15-150 keV band is 1.4 +- 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/913302/BA/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 25023 SUBJECT: GRB 190706B: Swift/UVOT Detection DATE: 19/07/07 19:29:34 GMT FROM: Paul Kuin at MSSL N. P. M. Kuin (UCL-MSSL) and A. Tohuvavohu (PSU) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 190706B 100 s after the BAT trigger (Tohuvavohu et al., GCN Circ. 24993). No optical afterglow consistent with the XRT position (Beardmore et al. GCN Circ. 24995) is detected in the initial UVOT exposures. Preliminary 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first finding chart (FC) exposure and subsequent exposures are: Filter T_start(s) T_stop(s) Exp(s) Mag white_FC 100 250 147 20.35 +/- 0.27 u_FC 312 562 246 >19.86 white 100 5778 519 >20.9 v 642 17542 561 >19.9 b 568 5644 292 >20.6 u 312 13071 647 >19.9 w1 691 11551 1204 >20.0 m2 666 7285 490 >19.6 w2 618 17284 1199 >20.5 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.15 in the direction of the burst (Schlegel et al. 1998).