//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 11411 SUBJECT: GRB 101117B: Swift detection of a burst DATE: 10/11/17 19:27:41 GMT FROM: Scott Barthelmy at NASA/GSFC C. W. Wolf (PSU), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), D. N. Burrows (PSU), S. Campana (INAF-OAB), N. Gehrels (NASA/GSFC), D. Grupe (PSU), S. T. Holland (CRESST/USRA/GSFC), J. A. Kennea (PSU), H. A. Krimm (CRESST/GSFC/USRA), W.B Landsman (GSFC), V. Mangano (INAF-IASFPA), C. B. Markwardt (NASA/GSFC) and P. T. O'Brien (U Leicester) report on behalf of the Swift Team: At 19:13:23 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 101117B (trigger=438675). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 172.909, -72.662 which is RA(J2000) = 11h 31m 38s Dec(J2000) = -72d 39' 41" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a two-spike structure with a duration of about 6 sec. The peak count rate was ~7000 counts/sec (15-350 keV), at ~3 sec after the trigger. The XRT began observing the field at 19:14:40.9 UT, 77.0 seconds after the BAT trigger. Using promptly downlinked data we find a fading, uncatalogued X-ray source located at RA, Dec 173.00251, -72.66317 which is equivalent to: RA(J2000) = 11h 32m 0.60s Dec(J2000) = -72d 39' 47.4" with an uncertainty of 3.7 arcseconds (radius, 90% containment). This location is 100 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 (1.33 x 10^21 cm^-2, Kalberla et al. 2005), with an excess column of 2.2 (+2.09/-1.81) x 10^21 cm^-2 (90% confidence). UVOT took a finding chart exposure of 150 seconds with the white filter starting 82 seconds after the BAT trigger. No credible afterglow candidate has been found in the initial data products. The 2.7' x 2.7' sub-image covers 100% of the XRT error circle. The estimated 3-sigma upper limit is white > 20.4 mag. No correction has been made for the expected Galactic extinction corresponding to a reddening of E_{B-V} = 0.38 mag. Photometry is on the UVOT photometry system of Poole et al. (2008). Burst Advocate for this burst is C. W. Wolf (cwolf AT astro.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/too.html.) //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 11412 SUBJECT: GRB 101117B: Swift/UVOT Discovery of an Optical Afterglow DATE: 10/11/17 19:42:13 GMT FROM: Stephen Holland at USRA/NASA/GSFC/SSC Stephen Holland (CRESST/USRA/GSFC) reports, on behalf of the UVOT Team The Swift/UVOT source list has an uncatalogued source at the location of the XRT afterglow (Wolf et al. 2010, GCNC 1141). Preliminary photometry indicates an approximate white magnitude of 18.2. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 11413 SUBJECT: GRB 101117B: Enhanced Swift-XRT position DATE: 10/11/17 23:59:36 GMT FROM: Phil Evans at U of Leicester M.R. Goad, J.P. Osborne, A.P. Beardmore and P.A. Evans (U. Leicester) report on behalf of the Swift-XRT team. Using 1061 s of XRT Photon Counting mode data and 1 UVOT images for GRB 101117B, 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 = 173.00136, -72.66293 which is equivalent to: RA (J2000): 11h 32m 0.33s Dec (J2000): -72d 39' 46.5" with an uncertainty of 1.7 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: 11414 SUBJECT: GRB 101117B: Swift-BAT refined analysis DATE: 10/11/18 00:14:30 GMT FROM: Scott Barthelmy at NASA/GSFC W. H. Baumgartner (GSFC/UMBC), S. D. Barthelmy (GSFC), J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (GSFC/UMBC), J. Tueller (GSFC), T. N. Ukwatta (GWU), C. W. Wolf (PSU) (i.e. the Swift-BAT team): Using the data set from T-60 to T+243 sec from recent telemetry downlinks, we report further analysis of BAT GRB 101117B (trigger #438675) (Wolf, et al., GCN Circ. 11411). The BAT ground-calculated position is RA, Dec = 172.991, -72.651 deg which is RA(J2000) = 11h 31m 57.8s Dec(J2000) = -72d 39' 04.7" with an uncertainty of 1.1 arcmin, (radius, sys+stat, 90% containment). The partial coding was 46%. The mask-weighted light curve shows two overlapping peaks starting at ~T-0.2 sec, peaking at ~T+1.0 sec, and roughly exponentially decaying out to ~T+40 sec. There is possible emission (at the 2-sigma c.l.) from around T+150 to T+220 sec. T90 (15-350 keV) is 5.2 +- 1.8 sec (estimated error including systematics). The time-averaged spectrum from T-0.1 to T+8.6 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.50 +- 0.09. The fluence in the 15-150 keV band is 1.1 +- 0.1 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T+0.74 sec in the 15-150 keV band is 4.5 +- 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/438675/BA/ This burst was called the "B" burst to avoid possible confusion with the earlier published XRF 101117A event by the MAXI team (GCN Circ 11410). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 11417 SUBJECT: GRB 101117B: Swift-XRT refined analysis DATE: 10/11/18 23:02:04 GMT FROM: Chris Wolf at PSU C. A. Wolf (PSU) and D. Grupe (PSU) report on behalf of the Swift-XRT team: We have analyzed 15.7 ks of XRT data for GRB 101117B (Wolf et al. GCN Circ. 11411), from 86 s to 63.0 ks after the BAT trigger. The data are entirely in Photon Counting (PC) mode. The light curve can be modeled with an initial power-law decay with an index of alpha=0.76 (+0.08, -0.09), followed by a break at T+1239 s to an alpha of 1.26 (+0.10, -0.09). A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 2.23 (+/-0.11). The best-fitting absorption column is 3.18 (+/-0.43) x 10^21 cm^-2, in excess of the Galactic value of 1.33 x 10^21 cm^-2 (Kalberla et al. 2005). The counts-to-observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 5.7 x 10^-11 (10.5 x 10^-11) erg cm^-2 count^-1. If the light curve continues to decay with a power-law decay index of 1.26, the count rate at T+24 hours will be 2.19 x 10^-3 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.25 x 10^-13 (2.30 x 10^-13) erg cm^-2 s^-1. The count rate at T+48 hours will be 0.89 x 10^-3 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 5.07 x 10^-14 (9.35 x 10^-14) erg cm^-2 s^-1. The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00438675. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 11420 SUBJECT: GRB 101117B: Swift/UVOT Observations of the Optical Afterglow DATE: 10/11/22 15:25:34 GMT FROM: Stephen Holland at USRA/NASA/GSFC/SSC S. T. Holland (CRESST/GSFC/USRA) and C. W. Wolf (PSU) report on the behalf of the Swift UVOT team: The Swift/UVOT observed the field of GRB 101117B starting 63 s after the BAT trigger (Wolf, et al., 2010, GCN Circ. 11411). Settled observations started at 82 s. We detect the optical afterglow (Holland, 2010, GCN Circ. 11412) in the U, B, and white filters. The refined UVOT position is RA (J2000) 11:32:00.54 = 173.00225 (deg) Dec (J2000) -72:39:45.9 = -72.66275 (deg) with an estimated uncertainty of 0.43 arcsec (radius, 90% confidence, statistical + systematic). This is 1.16 arcsec northwest of the UVOT-enhanced XRT position (Goad, et al., 2010, GCN Circ. 11413). Preliminary magnitudes, and 3-sigma upper limits for detecting a source in the finding charts and in the co-added images, are Filter T_start T_stop Exp(s) Mag Err ----------------------------------------------------------- white (fc) 82 232 147 17.81 0.08 u (fc) 295 545 246 18.68 0.15 v 626 646 20 >17.9 b 551 571 20 18.22 0.27 u 700 1325 59 >19.1 uvw1 675 1300 78 >19.3 uvm2 825 1275 58 >18.7 uvw2 601 1051 58 >19.0 white 575 595 20 19.20 0.34 ----------------------------------------------------------- The quoted magnitudes and upper limits have not been corrected for the expected Galactic extinction along the line of sight corresponding to a reddening of E_{B-V} = 0.38 mag (Schlegel, et al., 1998, ApJS, 500, 525). All photometry is on the UVOT photometry system described in Poole et al. (2008, MNRAS, 383, 627). The non-detection in the UVOT uvw1 filter, and the observed UVOT spectral energy distribution at 600 s, is consistent with GRB 101117B having a redshift of approximately z <= 3, although we can not rule out the non-detection in the ultraviolet being due to extinction in the host galaxy. The white light curve exhibits a power-law decay with an index of alpha = -0.8 +/- 0.1 between 82 and 6005 s after the BAT trigger. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 11421 SUBJECT: GRB 101117B: GROND Upper limits DATE: 10/11/22 19:05:49 GMT FROM: Jonny Elliott at MPE/GROND J. Elliott, R. Filgas, J. Greiner, P. Schady and T. Kruehler (all MPE Garching) report on behalf of the GROND team: We observed the field of GRB 101117B (Swift trigger 438675; Wolf et al., GCN #11411) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008, PASP 120, 405) mounted at the 2.2 m MPI/ESO telescope at La Silla Observatory (Chile). Observations started at 05:15 UT on November 19, 34 hours after the GRB trigger, and have total exposure of 6003 s in g'r'i'z' and 4800 s in JHK. They were performed at an average seeing of 2.0" and at an average airmass of 1.8. We do not detect a source within the UVOT error circle reported by Holland & Wolf (GCN #11420) down to the following 3 sigma upper limits (all in AB): g' > 23.7 r' > 23.8 i' > 23.5 z' > 23.3 J > 21.7, H > 21.2 and K > 20.4 The given limits are derived based on calibrating the images against GROND zeropoints and 2MASS field stars and are not corrected for the Galactic foreground extinction corresponding to a reddening of E_(B-V)= 0.38 in the direction of the burst (Schlegel et al. 1998).