//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 11798 SUBJECT: GRB 110318A: Swift detection of a burst DATE: 11/03/18 13:21:49 GMT FROM: Scott Barthelmy at NASA/GSFC B. Sbarufatti (INAF-OAB/IASFPA), S. D. Barthelmy (GSFC), M. M. Chester (PSU), P. D'Avanzo (INAF-OAB), V. D'Elia (ASDC), P. A. Evans (U Leicester), N. Gehrels (NASA/GSFC), J. M. Gelbord (PSU), C. Gronwall (PSU), C. Guidorzi (U Ferrara), S. T. Holland (CRESST/USRA/GSFC), J. A. Kennea (PSU), R. Margutti (INAF-OAB), A. Melandri (INAF-OAB), K. L. Page (U Leicester), P. Romano (INAF-IASFPA), C. J. Saxton (UCL-MSSL), M. H. Siegel (PSU), E. Sonbas (GSFC/USRA/Adiyaman Univ.) and C. A. Swenson (PSU) report on behalf of the Swift Team: At 13:14:19 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 110318A (trigger=449542). Swift did not slew to the burst because of the Sun observing constraint. The BAT on-board calculated location is RA, Dec 338.274, -15.282, which is RA(J2000) = 22h 33m 06s Dec(J2000) = -15d 16' 55" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve shows two main peaks with a duration of about 20 sec. The peak count rate was ~7000 counts/sec (15-350 keV), at ~2 sec after the trigger. Due to a Sun observing constraint, Swift cannot slew to the BAT position until 05:00 UT on 2011 April 11. There will thus be no XRT or UVOT data for this trigger before this time. Burst Advocate for this burst is B. Sbarufatti (boris.sbarufatti AT brera.inaf.it). 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: 11799 SUBJECT: GRB 110318B: Swift detection of a burst DATE: 11/03/18 15:38:31 GMT FROM: Scott Barthelmy at NASA/GSFC R. Margutti (INAF-OAB), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), A. P. Beardmore (U Leicester), S. Campana (INAF-OAB), P. D'Avanzo (INAF-OAB), P. A. Evans (U Leicester), N. Gehrels (NASA/GSFC), J. M. Gelbord (PSU), C. Gronwall (PSU), C. Guidorzi (U Ferrara), S. T. Holland (CRESST/USRA/GSFC), J. A. Kennea (PSU), H. A. Krimm (CRESST/GSFC/USRA), O. M. Littlejohns (U Leicester), V. Mangano (INAF-IASFPA), C. B. Markwardt (NASA/GSFC), F. E. Marshall (NASA/GSFC), A. Melandri (INAF-OAB), P. T. O'Brien (U Leicester), J. P. Osborne (U Leicester), K. L. Page (U Leicester), D. M. Palmer (LANL), P. Romano (INAF-IASFPA), B. Sbarufatti (INAF-OAB/IASFPA), M. H. Siegel (PSU), E. Sonbas (GSFC/USRA/Adiyaman Univ.) and C. A. Swenson (PSU) report on behalf of the Swift Team: At 15:27:09 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 110318B (trigger=449549). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 211.695, -51.559, which is RA(J2000) = 14h 06m 47s Dec(J2000) = -51d 33' 31" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve shows a couple peaks with a total duration of about 10 sec. The peak count rate was ~1100 counts/sec (15-350 keV), at ~2 sec after the trigger. The XRT began observing the field at 15:28:22.5 UT, 72.8 seconds after the BAT trigger. Using promptly downlinked data we find a fading, uncatalogued X-ray source located at RA, Dec 211.67805, -51.57933 which is equivalent to: RA(J2000) = 14h 06m 42.73s Dec(J2000) = -51d 34' 45.6" with an uncertainty of 3.8 arcseconds (radius, 90% containment). This location is 82 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 2.42 x 10^21 cm^-2 (Kalberla et al. 2005). The UVOT processed images are delayed and will be analyzed as soon as possible. Burst Advocate for this burst is R. Margutti (raffaella.margutti AT brera.inaf.it). 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: 11801 SUBJECT: GRB 110318B: Swift/UVOT Non-Detection of an Afterglow DATE: 11/03/18 16:00:34 GMT FROM: Stephen Holland at USRA/NASA/GSFC/SSC S. T. Holland (CRESST/USRA/GSFC) & R. Margutti (INAF-OAB) report on behalf of the Swift/UVOT team: UVOT took a finding chart exposure of the field of GRB 110318B (Margutti et al. 2011, GCNC 11800) of 150 seconds with the White filter starting 77 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. No correction has been made for the expected extinction corresponding to E(B-V) of 0.46. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 11802 SUBJECT: GRB 110318A: Swift-BAT refined analysis DATE: 11/03/18 18:14:45 GMT FROM: Scott Barthelmy at NASA/GSFC S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), 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), B. Sbarufatti (INAF-OAB/IASFPA), M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (MSU) (i.e. the Swift-BAT team): Using the data set from T-114 to T+595 sec from the recent telemetry downlink, we report further analysis of BAT GRB 110318A (trigger #449542) (Sbarufatti, et al., GCN Circ. 11798). The BAT ground-calculated position is RA, Dec = 338.292, -15.278 deg, which is RA(J2000) = 22h 33m 10.0s Dec(J2000) = -15d 16' 40.9" with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment). The partial coding was 27%. The mask-weighted light curve shows a small precursor peak between T-8 and T-2 sec. The main peak starts at ~T-1 sec, peaks at ~T+1 sec, and ends at ~T+15 sec. T90 (15-350 keV) is 16.0 +- 1.7 sec (estimated error including systematics). The time-averaged spectrum from T-13.0 to T+10.6 sec is best fit by a power law with an exponential cutoff. This fit gives a photon index 1.05 +- 0.23, and Epeak of 94.3 +- 23.7 keV (chi squared 43.1 for 56 d.o.f.). For this model the total fluence in the 15-150 keV band is 4.9 +- 0.2 x 10^-6 erg/cm2 and the 1-sec peak flux measured from T+1.95 sec in the 15-150 keV band is 8.0 +- 0.5 ph/cm2/sec. A fit to a simple power law gives a photon index of 1.58 +- 0.05 (chi squared 59.4 for 57 d.o.f.). 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/449542/BA/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 11803 SUBJECT: GRB 110318B: Enhanced Swift-XRT position DATE: 11/03/18 20:21:19 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 1818 s of XRT Photon Counting mode data and 2 UVOT images for GRB 110318B, 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 = 211.67808, -51.57883 which is equivalent to: RA (J2000): 14h 06m 42.74s Dec (J2000): -51d 34' 43.8" 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: 11804 SUBJECT: GRB 110318B: Swift-BAT refined analysis DATE: 11/03/18 21:01:05 GMT FROM: Scott Barthelmy at NASA/GSFC C. B. Markwardt (GSFC), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), R. Margutti (INAF-OAB), 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-60 to T+243 sec from the recent telemetry downlink, we report further analysis of BAT GRB 110318B (trigger #449549) (Margutti, et al., GCN Circ. 11799). The BAT ground-calculated position is RA, Dec = 211.691, -51.577 deg, which is RA(J2000) = 14h 06m 45.9s Dec(J2000) = -51d 34' 35.7" with an uncertainty of 1.7 arcmin, (radius, sys+stat, 90% containment). The partial coding was 85%. The mask-weighted light curve shows a single peak starting at ~T-2 sec, peaking at ~T+1 sec, and ending at ~T+5 sec. T90 (15-350 keV) is 4.8 +- 0.6 sec (estimated error including systematics). The time-averaged spectrum from T-1.7 to T+3.7 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.09 +- 0.17. The fluence in the 15-150 keV band is 2.9 +- 0.3 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from T+0.76 sec in the 15-150 keV band is 0.7 +- 0.1 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/449549/BA/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 11805 SUBJECT: GRB 110318A: Fermi GBM detection DATE: 11/03/18 22:15:54 GMT FROM: Gerard Fitzpatrick at UCD G. Fitzpatrick (UCD) reports on behalf of the Fermi GBM Team:  "At 13:14:16.70 UT on 18th March 2011, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 110318 (trigger 322146858 / 110318552),  which was also detected by the Swift/BAT (Sbarufatti et al. 2011,  GCN 11798). The GBM on-ground location is consistent with the Swift  position. The angle from the Fermi LAT boresight is 70 degrees. The GBM light curve consists of single peak with a duration (T90) of about 12 s (50-300 keV).  The time-averaged spectrum from T0-1 s to T0+10 s is   fit well with  a power law function with an exponential high-energy cutoff.  The power law index is -0.86 +/- 0.04 and the cutoff energy, parameterized as Epeak, is 114.70 +/- 3.72 keV A Band function fits the spectrum equally well with Epeak= 107.00 +/- 5.18 keV, alpha =-0.80 +/- 0.05, and beta = -2.74 +/- 0.25. The event fluence (10-1000 keV) in this time interval is  (8.05 +/- 0.15)E-6 erg/cm^2. The 1-sec peak photon flux measured  starting from T0-1 s in the 8-1000 keV band  is 10.97 +/- 0.29 ph/s/cm^2. The spectral analysis results presented above are preliminary;  final results will be published in the GBM GRB Catalog." [GCN OPS NOTE(19mar11): Per author's request, the citation for GCN Circ 11798 was corrected.] //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 11806 SUBJECT: GRB 110318B: Swift-XRT refined Analysis DATE: 11/03/18 23:46:59 GMT FROM: Raffaella Margutti at U. di Milano Bicocca R. Margutti, B. Sbarufatti, A. Melandri (INAF-OAB) report on behalf of the Swift-XRT team: We have analysed 4.9 ks of XRT data for GRB 110318B (Margutti et al. GCN Circ. 11799), from 83 s to 13.4 ks after the BAT trigger. The data are entirely in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Evans et al. (GCN. Circ 11803). The light curve can be modelled with a power-law decay with a decay index of alpha=1.10 (+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 2.3 (+/-0.3). The best-fitting absorption column is 5.2 (+1.5, -1.3) x 10^21 cm^-2, in excess of the Galactic value of 2.4 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 4.3 x 10^-11 (9.8 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 5.2 (+1.5, -1.3) x 10^21 cm^-2 Galactic foreground: 2.4 x 10^21 cm^-2 Excess significance: 6.5 sigma Photon index: 2.3 (+/-0.3) The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00449549. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 11809 SUBJECT: GRB 110318B: GROND upper limits DATE: 11/03/19 09:10:25 GMT FROM: Thomas Kruehler at MPE/MPI T. Kruehler, J. Greiner, F. Schrey (all MPE Garching), and S. Klose (TLS Tautenburg) report on behalf of the GROND team. We observed the field of GRB 110318B (Swift trigger 449549; Margutti et al., GCN #11800 simultaneously in g'r'i'z' with GROND (Greiner et al. 2008, PASP 120, 405) mounted at the 2.2 m MPI/ESO telescope at La Silla Observatory (Chile). Observation started at 07:40 UT, which is 16.2 h after the trigger, and were obtained under clear skies with an airmass of around 1.1 and seeing of 1" In stacked images with a total integration time of 25 min, we do not detect a source in the refined XRT error circle (Evans et al., GCN #11803) to the following upper limits (AB system): g' > 23.7 r' > 23.6 i' > 23.6 z' > 23.4 Given magnitudes are calibrated against GROND zeropoints and are not corrected for the expected Galactic foreground extinction corresponding to a reddening of E_(B-V)=0.46 mag in the direction of the burst (Schlegel et al. 1998). GROND is currently undergoing hardware maintenance, and hence no NIR data are available for this burst. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 11816 SUBJECT: GRB 110318B: Swift/UVOT Upper Limits DATE: 11/03/21 14:53:29 GMT FROM: Stephen Holland at USRA/NASA/GSFC/SSC S. T. Holland (CRESST/USRA/GSFC) and R. Margutti (INAF-OAB) report on behalf of the Swift/UVOT team: The Swift/UVOT observed the field of GRB 110318B starting 58 s after the BAT trigger (Margutti, et al., 2011, GCN Circ. 11799). Settled observations started at 76 s. We do not detect an optical afterglow at the UVOT-enhanced XRT position (Evans, et al., 2011, GCN Circ. 11803) in any of the UVOT filters. Preliminary 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 ----------------------------------------------- white (fc) 76 226 147 >21.5 868 1018 147 >21.5 v 619 7035 529 >20.6 b 545 7693 370 >21.2 u 289 7649 756 >21.2 uvw1 668 7445 529 >20.8 uvm2 5602 7239 393 >20.5 uvw2 1024 6829 236 >20.3 white 76 6623 626 >22.2 ----------------------------------------------- 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} = 0.46 mag (Schlegel, et al., 1998, ApJS, 500, 525). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 11822 SUBJECT: GRB110318B : MOA optical upper limit DATE: 11/03/25 16:40:17 GMT FROM: Suzuki Daisuke at MOA-II D. Suzuki (STE Lab. Nagoya Univ.), P.J. Tristram (Mt. John University Observatory), S. Kobara, K. Omori, H. Naito and T. Sako (STE Lab. Nagoya Univ.) on behalf of the MOA Collaboration report : We searched for an optical afterglow of GRB110318B (GCN 11799, R. Margutti et al.) starting from 15:40 UT on 2011 March 18 (13 minutes after the burst) with the MOA-II 1.8m telescope at Mt.John observatory in New Zealand. In a single image of a 60 sec exposure with a wideband Red filter (center wavelength ~ 750nm and FWHM ~ 250nm), we did not find any object within the error circle of the Swift XRT source position (GCN 11803, P.A. Evans et al.). A 3 sigma upper limit is set in the I magnitude at 20.7 mag. This photometry was done by using the DoPhot and calibrated against the USNO-B1.0 catalog stars, and not corrected for the Galactic extinction.