//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 10470 SUBJECT: GRB 100305A: Swift detection of a burst DATE: 10/03/05 09:22:05 GMT FROM: David Palmer at LANL E. Troja (NASA/GSFC/ORAU), S. D. Barthelmy (GSFC), A. P. Beardmore (U Leicester), S. Campana (INAF-OAB), J. R. Cummings (NASA/UMBC), A. de Ugarte Postigo (INAF-OAB), P. A. Evans (U Leicester), J. M. Gelbord (PSU), O. Godet (U Leicester), C. Guidorzi (U Ferrara), S. T. Holland (CRESST/USRA/GSFC), H. A. Krimm (CRESST/GSFC/USRA), R. Margutti (Univ Bicocca&OAB), C. Pagani (U Leicester), K. L. Page (U Leicester), D. M. Palmer (LANL), B. Sbarufatti (INAF-OAB/IASFPA), M. H. Siegel (PSU) and R. L. C. Starling (U Leicester) report on behalf of the Swift Team: At 09:05:38 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 100305A (trigger=414905). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 168.365, +42.376 which is RA(J2000) = 11h 13m 28s Dec(J2000) = +42d 22' 34" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a single-peaked structure with a total duration of about 20 sec, starting at ~T+50 relative to the start of the image trigger interval. The peak count rate was ~500 counts/sec (15-350 keV), at ~65 sec after the trigger. The XRT began observing the field at 09:07:57.6 UT, 139.2 seconds after the BAT trigger. Using promptly downlinked data we find a bright, uncatalogued X-ray source located at RA, Dec 168.36762, 42.40281 which is equivalent to: RA(J2000) = 11h 13m 28.23s Dec(J2000) = +42d 24' 10.1" with an uncertainty of 4.4 arcseconds (radius, 90% containment). This location is 96 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 2.14e+20 cm^-2 (Kalberla et al. 2005). The initial flux in the 2.5 s image was 4.86e-10 erg cm^-2 s^-1 (0.2-10 keV). UVOT took a finding chart exposure of 122 seconds with the White filter starting 144 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 0.01. Burst Advocate for this burst is E. Troja (eleonora.troja AT 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: 10471 SUBJECT: GRB 100305A: P60 Observations DATE: 10/03/05 10:48:37 GMT FROM: S. Bradley Cenko at Caltech S. B. Cenko (UC Berkeley) reports on behalf of a larger collaboration: We have imaged the field of GRB100305A (Troja et al., GCN 10470) with the automated Palomar 60-inch telescope. Images were obtained in the Sloan g', r', i', and z' filters beginning at 09:09 UT on 5 March 2010 (~ 3.5 minutes after the burst). In coadded images, we find no sources inside the XRT error circle to the following limits (calculated with respect several point sources in the SDSS DR7 catalog): Filter Mid-point t_burst Exposure Magnitude ------------------------------------------------------------------------- r' 09:25 19.5 min 720.0 > 22.0 z' 09:27 21.7 min 420.0 > 20.5 i' 09:28 23.3 min 660.0 > 22.0 The lack of an optical afterglow candidate, together with the long duration and lack of X-ray absorption in excess of the Galactic value (Troja et al., GCN 10470), make GRB100305A a candidate high redshift event. We encourage additional follow-up at longer wavelengths. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 10472 SUBJECT: GRB 100305A: PAIRITEL NIR Upper Limits DATE: 10/03/05 10:57:48 GMT FROM: Adam Morgan at U.C. Berkeley A. N. Morgan, J. S. Bloom, and S. B. Cenko (UC Berkeley) report: We observed the field of GRB 100305A (Troja et al., GCN 10470) with the 1.3m PAIRITEL located at Mt. Hopkins, Arizona. Observations began at 2010-03-05 09h29m30s UT, ~0.4 hours after the Swift trigger.  In initial mosaics (effective exposure time of ~795.6 seconds) taken simultaneously in the J, H, and Ks filters, we do not detect any sources within the XRT error circle. The preliminary photometry yields: post_burst t_mid(min)  exp(s)  filt    U. Limit (3 sig) 34.6        795.6  J       > 19.2 34.6        795.6  H       > 18.0 34.6        795.6   Ks      > 17.3 Observations are ongoing.  All magnitudes given in the Vega system, calibrated to 2MASS.  No correction for Galactic extinction has been made to the above reported values. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 10473 SUBJECT: GRB 100305A: Gemini-N OT candidate DATE: 10/03/05 12:44:33 GMT FROM: Antonino Cucchiara at PSU A. Cucchiara (PSU), report on behalf of a larger collaboration: "On March 5.42 UT we observed the field of GRB 100305A (Troja et al., GCN 10470) with the Gemini-N telescope and the GMOS instrument. In our 300s r'-band and 900s i'-band images we clearly detect a source inside the XRT error circle at the following position: RA (J2000) = 11:13:28.30 Dec (J2000) = 42:24:10.50 with an uncertainty of 0.5" in each coordinate. Using 2 USNO-B1 stars we calibrated our photometry and obtained r' = 23.95 +- 0.30 mag i' = 23.71 +- 0.50 mag At the moment no evidence of fading can be addressed. Further analysis are in progress. We thank the Gemini staff for performing this observation, in particular Andrew Stephens." //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 10474 SUBJECT: GRB 100305A: Enhanced Swift-XRT position DATE: 10/03/05 13:32:10 GMT FROM: Phil Evans at U of Leicester J.P. Osborne, A.P. Beardmore, P.A. Evans and M.R. Goad (U. Leicester) report on behalf of the Swift-XRT team. Using 2448 s of XRT Photon Counting mode data and 6 UVOT images for GRB 100305A, 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 = 168.36691, +42.40393 which is equivalent to: RA (J2000): 11h 13m 28.06s Dec (J2000): +42d 24' 14.1" 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: 10475 SUBJECT: GRB 100305A Optical Observations DATE: 10/03/05 14:57:01 GMT FROM: Arne A. Henden at AAVSO A. Henden (AAVSO), J. Gross (SRO), B. Denny (DC-3), D. Terrell (SwRI), and W. Cooney (SRO) report: We obtained imagery of the GRB 100305A burst reported by Troja et al. (GCN 10470) using the Sonoita Research Observatory (SRO) 35cm telescope in southern Arizona, utilizing an automatic VOevent trigger. The exposures began about 3 minutes after the burst and continued for approximately two hours. 20 Rc-band, 10 V-band, and a set of BVRI exposures for field calibration were acquired. Inspection of the enhanced Swift-XRT position given by Osborne, et al. (GCN 10474) does not show any optical afterglow to the following limits, based on using star USNOB 1323-0268523 at 11:13:38.45 +42:23:45.7 as having magnitudes R=15.98 and V=16.67): UTmid delT exp filt lim (hrs) (min) (# x s) 09.1544 003.63 01x060 Rc 19.1 09.2379 008.64 10x060 Rc 20.5 09.4821 023.29 05x180 Rc 21.3 09.8411 044.83 05x300 Rc 21.6 10.8564 105.75 10x300 V 21.1 The AAVSO thanks the Curry Foundation for its support of the AAVSO International High Energy Network. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 10476 SUBJECT: GRB 100305A: Swift-XRT refined analysis DATE: 10/03/05 15:54:41 GMT FROM: Antonio Deugarte at IAA-CSIC A. de Ugarte Postigo, R. Margutti, B. Sbarufatti (INAF-OAB) and E. Troja (NASA/GSFC/ORAU) report on behalf of the Swift-XRT team: We have analysed 2.5 ks of the Swift-XRT data for GRB 100305A (Troja et al. GCN Circ. 10470), from 145 s to 6.0 ks after the BAT trigger. The data comprise 84 s in Windowed Timing (WT) mode with the remainder in Photon Counting (PC) mode. The best position of the X-ray afterglow is the UVOT enhanced XRT position given in Osborne et al. (GCN Circ. 10474). Analysis of the light curve shows an initial steep power-law decay with an index of alpha=3.5 (+/-0.4), followed by a break at T+300 s to an alpha of 0.84 (+0.11, -0.58). A spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 1.96 (+0.21,-0.20). The best-fitting absorption column is 1.7 (+/-0.5) x 10^21 cm^-2, in excess of the Galactic value of 2.1 x 10^20 cm^-2 (Kalberla et al. 2005). The PC mode spectrum has a photon index of 2.14 (+0.24,-0.20) and a best-fitting absorption column of 1.7 (+0.60, -0.30) x 10^21 cm^-2. The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 3.8 x 10^-11 (5.8 x 10^-11) erg cm^-2 count^-1. If the light curve continues to decay with a power-law decay index of 0.84, 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 5.8 x 10^-13 (8.7 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/00414905. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 10477 SUBJECT: GRB 100305A: Swift/UVOT Upper Limits DATE: 10/03/05 18:24:08 GMT FROM: Mike Siegel at PSU/Swift MOC M. H. Siegel (PSU) and E. Troja (NASA/GSFC/ORAU) report on behalf of the Swift/UVOT team. The Swift/UVOT began settled observations of the field of GRB 100305A 144s after the BAT trigger (Troja et al., GCN Circ. 10470). Data summed from the first and second orbits do not reveal a source at the enhanced position of the X-ray afterglow (Osborne et al., GCN Circ. 10474) or the candidate afterglow reported by Cucchiara et al. (GCN Circ. 10473). The 3-sigma upper limits for the finding chart (fc) and summed exposures are reported below: FILTER T_start(s) T_stop Exposure Mag/3UL ======================================================== white fc 144 266 120 > 20.60 white 4636 4836 196 > 21.10 v 3612 5247 393 > 19.85 b 4432 6048 373 > 20.68 u 4227 5863 393 > 20.45 uvw1 4022 5656 393 > 20.46 uvm2 3817 5451 393 > 20.2 uvw2 4842 5042 196 > 20.17 ======================================================= The above magnitudes are not corrected for the Galactic extinction corresponding to a reddening of E_{B-V} = 0.01 (Schlegel et al., 1998, ApJS, 500, 525). The photometry is on the UVOT photometric system described in Poole et al. (2008, MNRAS, 383, 627). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 10478 SUBJECT: GRB 100305A: Gemini z'-band observation DATE: 10/03/05 19:56:11 GMT FROM: Antonino Cucchiara at PSU A. Cucchiara (PSU), report on behalf of a larger collaboration: "We continued our observations of GRB 100305A with the Gemini-N telescope mounted with the GMOS camera. A sequence of z'-band images has been taken for a total exposure time of 15 min. No clear object is visible in the position of the optical afterglow previously reported (GCN 10473) at the following 3-sigma upper limit: z' > 23.42 mag We also report a corrected error measure in our photometry. The correct magnitude estimates at T0 + 2h are: r' = 23.95 +- 0.30 mag i' = 23.71 +- 0.06 mag We apologize for any inconvenience this may have caused." //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 10479 SUBJECT: GRB 100305A, Swift-BAT refined analysis DATE: 10/03/05 21:51:53 GMT FROM: Hans Krimm at NASA-GSFC H. A. Krimm (GSFC/USRA), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC), E. E. Fenimore (LANL), N. Gehrels (GSFC), C. B. Markwardt (GSFC/UMD), D. M. Palmer (LANL), A. M. Parsons (GSFC), T. Sakamoto (GSFC/UMBC), G. Sato (ISAS), M. Stamatikos (GSFC/ORAU), E. Troja (NASA/GSFC/ORAU), 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 the recent telemetry downlink, we report further analysis of BAT GRB 100305A (trigger #414905) (Troja, et al., GCN Circ. 10470). The BAT ground-calculated position is RA, Dec = 168.373, 42.381 deg which is RA(J2000) = 11h 13m 29.5s Dec(J2000) = +42d 22' 50.7" with an uncertainty of 1.9 arcmin, (radius, sys+stat, 90% containment). The partial coding was 22%. The mask-weighted light curve shows a broad structure of two overlapping peaks beginning at T+0 and continuing to T+80 sec with the highest peak at T+60 sec. There is soft, low-level emission extending to ~T+200 sec. T90 (15-350 keV) is 69.7 +- 8.7 sec (estimated error including systematics). The time-averaged spectrum from T-9.2 to T+70.3 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.27 +- 0.23. The fluence in the 15-150 keV band is 1.5 +- 0.2 x 10^-6 erg/cm^2. The 1-sec peak photon flux measured from T+62.72 sec in the 15-150 keV band is 0.9 +- 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/414905/BA/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 10481 SUBJECT: GRB 100305A: Super-LOTIS early observations DATE: 10/03/09 01:04:25 GMT FROM: Adria C. Updike at Clemson U Adria C. Updike (Clemson University), Peter A. Milne (Steward Observatory), G. Grant Williams (MMTO), and Dieter H. Hartmann (Clemson University) report: We observed the field of GRB 100305A (Troja et al., GCN 10470) with the 0.6m Super-LOTIS telescope located at Kitt Peak National Observatory beginning 106 seconds after the trigger. Observations were carried out in the R band for approximately 45 minutes under good conditions. We do not detect any sources within the XRT enhanced error circle (Osborne et al., GCN 10474) or the source detected by Gemini-N (Cucchiara, GCN 10473). Band Exptime co-adds time UL ------------------------------------- R 10 5 106 > 17.5 R 20 5 202 > 19.2 R 60 30 389 > 20.5 Exptime is given in seconds; time is seconds after trigger of first observation. All limits given relative to USNO B1.0 field stars. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 10482 SUBJECT: GRB100305A: Optical upper limits at IAO DATE: 10/03/12 13:19:52 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 100305A (Troja et al. GCNC 10470) 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 2010-03-05 13:03:55 UT (~4h after the burst). We did not find any new point source in the XRT error circle (Osborne et al., GCNC 10474) in all the three bands. Three sigma upper limits of the OT are listed below. We used SDSS catalog for flux calibration. T0+[day] MID-UT T-EXP[sec] g' Rc Ic ------------------------------------------------------ 0.18816 13:36:35 3300.0 >22.1 >21.6 >20.4 ------------------------------------------------------ T0+ : Elapsed time after the burst [day] T-EXP: Total Exposure time [sec]