//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 11773 SUBJECT: GRB 110305A: Swift detection of a burst DATE: 11/03/05 07:00:46 GMT FROM: David Palmer at LANL D. Grupe (PSU), W. H. Baumgartner (GSFC/UMBC), J. M. Gelbord (PSU), E. A. Hoversten (PSU), C. B. Markwardt (NASA/GSFC), D. M. Palmer (LANL), E. Sonbas (GSFC/USRA/Adiyaman Univ.), M. C. Stroh (PSU) and C. W. Wolf (PSU) report on behalf of the Swift Team: At 06:38:01 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 110305A (trigger=448229). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 260.877, -15.790 which is RA(J2000) = 17h 23m 31s Dec(J2000) = -15d 47' 23" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a flat-topped structure with a superimposed short spike and an overall duration of about 10 sec. The peak count rate was ~1500 counts/sec (15-350 keV), at ~2 sec after the trigger. The XRT began observing the field at 06:39:50.2 UT, 109.0 seconds after the BAT trigger. Using promptly downlinked data we find an uncatalogued X-ray source with an enhanced position: RA, Dec 260.8809, -15.8023 which is equivalent to: RA(J2000) = 17h 23m 31.42s Dec(J2000) = -15d 48' 08.2" with an uncertainty of 2.2 arcseconds (radius, 90% containment). This location is 46 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 consistent with the Galactic value of 1.73 x 10^21 cm^-2 (Kalberla et al. 2005). Due to bright stars in the field there will be no white finding chart for this field. UVOT information is not available at this time. Burst Advocate for this burst is D. Grupe (grupe 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: 11774 SUBJECT: GRB 110305A: GROND Detection of Optical Afterglow DATE: 11/03/05 11:56:58 GMT FROM: Patricia Schady at MPE/Swift A. Nicuesa Guelbenzu (TLS Tautenburg), V. Sudilovsky, P. Schady and J. Greiner (MPE Garching) report on behalf of the GROND team: We observed the field of GRB 110305A (Swift trigger 448229; Grupe et al., GCN #11773) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008, PASP 120, 405) mounted at the 2.2m MPI/ESO telescope at La Silla Observatory (Chile). Observations started at 06:40 UT on March 5th, 2 minutes after the GRB trigger. They were performed at an average seeing of 0.8" and at an average airmass of 1.8. We found a fading source within the 2.2" Swift/XRT error circle reported by Grupe et al. (GCN #11773) at RA (J2000.0) = 17h 23m 31.3s DEC (J2000.0) = -15d 48' 08.8" with an uncertainty of 0.3" in each coordinate. The source decayed by 0.8mag in 60.5 minutes, suggesting that it is the optical afterglow of GRB110305A. At T+116.9 minutes the source had an r'-band magnitude of 23.7 +/- 0.1. These measurements are not corrected for the considerable Galactic foreground extinction corresponding to a reddening of E(B-V)=0.390 mag in the direction of the burst (Schlegel et al. 1998). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 11776 SUBJECT: GRB 110305A: Swift-BAT refined analysis DATE: 11/03/05 14:24:03 GMT FROM: Scott Barthelmy at NASA/GSFC J. R. Cummings (GSFC/UMBC), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), N. Gehrels (GSFC), D. Grupe (PSU), H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (GSFC/UMBC), M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (MSU) (i.e. the Swift-BAT team): Using the data set from T-61 to T+242 sec from the recent telemetry downlink, we report further analysis of BAT GRB 110305A (trigger #448229) (Grupe, et al., GCN Circ. 11773). The BAT ground-calculated position is RA, Dec = 260.877, -15.810 deg which is RA(J2000) = 17h 23m 30.4s Dec(J2000) = -15d 48' 37.6" with an uncertainty of 1.9 arcmin, (radius, sys+stat, 90% containment). The partial coding was 22%. The mask-weighted light curve shows a single pulse starting at ~T-1 sec and ending at ~T+12 sec. T90 (15-350 keV) is 12.0 +- 2.2 sec (estimated error including systematics). The time-averaged spectrum from T-0.9 to T+12.1 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.62 +- 0.19. The fluence in the 15-150 keV band is 8.0 +- 1.0 x 10^-07 erg/cm2. The 1-sec peak photon flux measured from T+6.06 sec in the 15-150 keV band is 1.2 +- 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/448229/BA/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 11777 SUBJECT: GRB 110305A: Enhanced Swift-XRT position DATE: 11/03/05 23:28:26 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 451 s of XRT Photon Counting mode data and 1 UVOT images for GRB 110305A, 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 = 260.88069, -15.80241 which is equivalent to: RA (J2000): 17h 23m 31.37s Dec (J2000): -15d 48' 08.7" 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: 11778 SUBJECT: GRB 110305A: Swift-XRT refined Analysis DATE: 11/03/06 16:43:19 GMT FROM: Dirk Grupe at PSU/Swift-XRT D. Grupe (PSU) reports on behalf of the Swift-XRT team: We have analyzed 34 ks of XRT data for GRB 110305A (Grupe et al. GCN Circ. 11773), from 116 s to 99.9 ks after the BAT trigger. The data are entirely in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Goad et al. (GCN. Circ 11777). The light curve can be modeled with a single power-law decay with a decay index of alpha=1.12 (+0.07, -0.06). A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 1.98 (+0.22, -0.20). The best-fitting absorption column is consistent with the Galactic value of 1.7 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 4.9 x 10^-11 (6.8 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 1.7 x 10^21 cm^-2 Galactic foreground: 1.7 x 10^21 cm^-2 Excess significance: Photon index: 1.98 (+0.22, -0.20) The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00448229. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 11779 SUBJECT: GRB 110305A: Swift/UVOT Upper Limits DATE: 11/03/06 17:12:42 GMT FROM: Stefan Immler at NASA/GSFC S. Immler (NASA/CRESST/GSFC) and D. Grupe (PSU) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 110305A 113 s after the BAT trigger (Grupe et al., GCN Circ. 11773). No optical afterglow consistent with the GROND position (Guelbenzu et al., GCN Circ. 11774) 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) exposure and subsequent exposures are: Filter T_start(s) T_stop(s) Exp(s) Mag white_FC 113 263 147 >20.5 u_FC 271 521 246 >19.6 white 113 18938 1608 >22.3 v 601 11519 1203 >19.7 b 527 24719 2136 >20.9 u 271 30501 3468 >21.5 w1 650 29759 2976 >20.9 m2 632 28858 2261 >20.8 w2 749 7376 426 >19.8 The values quoted above are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.39 in the direction of the burst (Schlegel et al. 1998). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 11780 SUBJECT: GRB110305A: MITSuME Ishigakijima Optical upper limits DATE: 11/03/07 12:46:17 GMT FROM: Daisuke Kuroda at OAO/NAOJ D. Kuroda (OAO, NAOJ), H. Hanayama, T. Miyaji, J. Watanabe (IAO, NAOJ), K. Yanagisawa (OAO, NAOJ), M. Yoshida (Hiroshima), K. Ohta (Kyoto) and N. Kawai(Tokyo Tech) report on behalf of the MITSuME collaboration: We observed the field of GRB 110305A (Grupe et al., GCNC 11773) with the optical three color (g', Rc and Ic) CCD camera attached to the Murikabushi 1m telescope of Ishigakijima Astronomical Observatory. The observation started on 2011-03-05 18:37:53 UT (~12 hours after the burst). We could not detected the previously reported afterglow (Guelbenzu et al., GCNC 11774) in all the three bands. Three sigma upper limits of the OT are listed below. We used GSC2.3 catalog for flux calibration. #T0+[day] MID-UT T-EXP[sec] g' Rc Ic ----------------------------------------------------- 0.51372 18:57:46 1620.0 >19.8 >20.1 >19.3 ----------------------------------------------------- T0+ : Elapsed time after the burst [day] T-EXP: Total Exposure time [sec] //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 11781 SUBJECT: GRB 110305A: REM detection of a possible NIR afterglow DATE: 11/03/07 15:08:51 GMT FROM: Paolo D'Avanzo at INAF-OAB D. Fugazza, P. D'Avanzo, S. Covino, S.D. Vergani, A. Melandri (INAF-OAB) on behalf of a larger collaboration report: The robotic 60-cm REM telescope located at La Silla (Chile) observed automatically the field of GRB 110305A (Grupe et al. GCN 11773) with the ROSS optical and REMIR near-infrared cameras in imaging mode. Observations started 93s from the GRB time (51s from the trigger time). No counterpart is visible in the optical frames, down to R > 16 (3sigma c.l., calibrated against the USNO B1.0 catalogue) while an object is visible with low significance in the first coadded NIR frames at a position consistent with the one of the optical afterglow (Nicuesa Guelbenzu et al. GCN 11774). Preliminary photometry shows that the source has H = 15.0 +/- 0.3 (calibrated against the 2MASS catalogue) at t-t0 = 4.5 min and is not detected anymore at t-t0 = 26.3 min down to a limiting magnitude H > 16.5 (3sigma c.l.). This implies an early power-law decay with index steeper than 0.8, consistent with the reported X-ray decay (Grupe, GCN 11778).