//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 11603 SUBJECT: GRB 110128A: Swift detection of a burst DATE: 11/01/28 01:55:36 GMT FROM: Scott Barthelmy at NASA/GSFC D. Grupe (PSU), S. D. Barthelmy (GSFC), N. Gehrels (NASA/GSFC), J. M. Gelbord (PSU), S. T. Holland (CRESST/USRA/GSFC), E. A. Hoversten (PSU), J. A. Kennea (PSU), C. B. Markwardt (NASA/GSFC), F. E. Marshall (NASA/GSFC), D. M. Palmer (LANL), M. H. Siegel (PSU), E. Sonbas (GSFC/USRA/Adiyaman Univ.) and E. Troja (NASA/GSFC/ORAU) report on behalf of the Swift Team: At 01:44:33 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 110128A (trigger=443861). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 193.874, +28.080 which is RA(J2000) = 12h 55m 30s Dec(J2000) = +28d 04' 47" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve shows a weak peak with a duration of about 20 sec. The peak count rate was ~1000 counts/sec (15-350 keV), at ~1 sec after the trigger. The XRT began observing the field at 01:46:53.5 UT, 140.5 seconds after the BAT trigger. Using promptly downlinked data we find a fading, uncatalogued X-ray source located at RA, Dec 193.89471, 28.06508 which is equivalent to: RA(J2000) = 12h 55m 34.73s Dec(J2000) = +28d 03' 54.3" with an uncertainty of 3.8 arcseconds (radius, 90% containment). This location is 84 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 9.02 x 10^19 cm^-2 (Kalberla et al. 2005). UVOT took a finding chart exposure of 150 seconds with the White filter starting 143 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 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: 11604 SUBJECT: GRB 110128A: TAROT Calern observatory upper limits DATE: 11/01/28 02:29:39 GMT FROM: Myrtille LAAS-BOUREZ at U.Western Australia GRB 110128A: TAROT Calern observatory upper limits ---------------------------------------------------------------------- Klotz A. (CESR-OMP), Gendre B. (ASDC), Boer M. (OHP-OAMP), Atteia J.L. (LATT-OMP), Laas-Bourez M. (UWA/ICRAR) report: We imaged the field of GRB 110128A detected by SWIFT (trigger 443861) with the TAROT robotic telescope (D=25cm) located at the Calern observatory, France. The observations started 73.7s after the GRB trigger (15s after the notice). The elevation of the field increased from 58 degrees above horizon and weather conditions were good. The date of trigger : t0 = 2011-01-28T01:44:32.640 We do not detect any OT with a limiting magnitude of: The first image is 60.0s exposure in tracking mode: t0+73.7s to t0+133.7s : R > 16.9 The five following images are 30.0s exposure in tracking mode: t0+148.6s to t0+178.6s : R > 16.4 to+193.7s to t0+223.7s : R > 16.4 to+238.9s to t0+268.9s : R > 15.9 to+284.0s to t0+314.0s : R > 15.9 to+329.2s to t0+359.2s : R > 16.9 We co-added a series of exposures: t0+73.7s to t0+359.2s : R > 18.8 Magnitudes were estimated with the nearby USNO-B1 stars and are not corrected for galactic dust extinction. N.B. Galactic coordinates are lon= 79.7852 lat=+88.6911 and the galactic extinction in R band is 0.009 magnitudes estimated from D. Schlegel et al. 1998ApJ...500..525S. This message may be cited. ====================================================================== [GCN OPS NOTE(29oct11): The missing "A" was added the GRB name.] //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 11605 SUBJECT: GRB 110128A: Afterglow detection from NOT DATE: 11/01/28 03:41:05 GMT FROM: Antonio Deugarte at IAA-CSIC A. de Ugarte Postigo, D. Malesani (Dark/NBI) J. McCormac (Queens Univ., Belfast) and P. Jakobsson (U. Iceland) report on behalf of a larger collaboration: We have imaged the field of GRB 110128A (Grupe et al. GCN 11603) with the 2.5m NOT telescope at Roque de los Muchachos Observatory (La Palma, Spain) starting at 2:57 UT (1.22h after the burst). We detect an R~22.2 (as compared to USNO-B1.0) object at coordinates: R.A.: 12:55:35.10 Dec.: +28:03:54.1 This object is not present in SDSS DR8. We propose it as the afterglow of GRB 110128A //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 11606 SUBJECT: GRB 110128A: Enhanced Swift-XRT position DATE: 11/01/28 09:50:33 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 920 s of XRT Photon Counting mode data and 1 UVOT images for GRB 110128A, 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 = 193.89661, +28.06511 which is equivalent to: RA (J2000): 12h 55m 35.19s Dec (J2000): +28d 03' 54.4" with an uncertainty of 1.9 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: 11607 SUBJECT: GRB 110128A: VLT/X-shooter redshift DATE: 11/01/28 12:26:53 GMT FROM: Nial Tanvir at U.Leicester M. Sparre, A. de Ugarte Postigo, J. P. U. Fynbo , D. Malesani, B. Milvang-Jensen (Dark/NBI), S. D. Vergani, H. Flores (GEPI/Obs. de Paris), P. Goldoni (APC/Univ. Paris 7 and SAp/CEA), and N. R. Tanvir (U. Leicester) report on behalf of the X-shooter GRB GTO collaboration: We observed the optical afterglow of GRB 110128A (Grupe et al., GCN 11603; de Ugarte Postigo et al., GCN 11605) with the ESO VLT equipped with X-shooter. Observations lasted for two hours, with a mean time 2011 Jan 28.345 UT (6.55 hr after the GRB). Sky transparency was non optimal, but the seeing was around 0.9". We detect a broad damped Lyman alpha feature, and other absorption lines of OI, CII, SiIV, CIV, SiII and FeII at a common redshift of z=2.339.  We also find an absorption feature at about 4960A which we tentatively identify as an intervening CIV system at z=2.20. We acknowledge excellent support from the astronomers at the VLT, Dieter Nuernberger and Alvaro Alvarez. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 11608 SUBJECT: GRB 110128A: WHT redshifts of nearby field galaxies DATE: 11/01/28 14:21:48 GMT FROM: Nial Tanvir at U.Leicester N. R. Tanvir, K. Wiersema (U. Leicester), A. J. Levan (U. Warwick), A. Kamble (U. Wisconsin), A. Cardwell (ING) and E. M. Ratti (SRON) report on behalf of a larger collaboration: We obtained spectroscopy of the afterglow of GRB 110128A (GCN 11603, GCN 11605) and of two field galaxies nearby, using the 4.2 William Herschel Telescope on La Palma.  Observations began at 04:26 UT, approximately 2.7 hours post-burst, and comprised a 60 minute total exposure. The spectra cover a wavelength range from about 4500A to 9400A. The signal-to-noise, of the afterglow spectrum is not sufficient to confirm the redshift reported in Sparre et al. in GCN 11607 (and note, our spectral range did not cover the DLA feature), however we did measure the redshifts of two field galaxies which are sufficiently close to the line of sight that they might produce absorption in the afterglow: Gal 1: RA=12:55:35.38, dec=+28:03:57.6 z=0.639 based on [OII]3727, CaII H & K, Hbeta Offset from afterglow=5 arcsec, corresponding to ~35 kpc impact parameter to GRB Gal 2: RA=12:55:36.40, dec=+28:04:12.1 z=0.109 based on Ha and [NII] Offset from afterglow=25 arcsec, corresponding to ~50 kpc impact parameter to GRB //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 11610 SUBJECT: GRB 110128A: Swift-XRT refined Analysis DATE: 11/01/28 15:29:47 GMT FROM: Dirk Grupe at PSU/Swift-XRT D. Grupe (PSU) reports on behalf of the Swift-XRT team: We have analyzed 11 ks of XRT data for GRB 110128A (Grupe et al. GCN Circ. 11603), from 125 s to 30.0 ks after the BAT trigger. The data comprise 9 s in Windowed Timing (WT) mode (taken while Swift was slewing), with the remainder in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Osborne et al. (GCN. Circ 11606). The light curve can be modeled with an initial decay slope alpha-1 = 2.3+/-0.5 and a break at 700 (-200,+600) s followed by a decay slope of alpha-2 = 0.6+/-0.3. Currently we are in the plateau phase. At this point predictions of the behavior of the light curve are unreliable. A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 1.64 (+0.22, -0.21). The best-fitting absorption column is consistent with the Galactic value of 9.0 x 10^19 cm^-2 (Kalberla et al. 2005). The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 4.0 x 10^-11 (4.1 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Galactic foreground: 9.0 x 10^19 cm^-2 Intrinsic column: 0.0 (+3.0, -0.0) x 10^21 cm^-2 at z=2.339 Photon index: 1.64 (+0.22, -0.21) The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00443861. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 11612 SUBJECT: GRB 110128A: Swift/UVOT observations DATE: 11/01/28 15:44:03 GMT FROM: Samantha Oates at MSSL S. R. Oates (MSSL-UCL) & D. Grupe (PSU) report on behalf of the Swift- UVOT team The Swift/UVOT began settled observations of the field of GRB 110128A 144 s after the BAT trigger (Grupe et al., GCN Circ. 11603). The optical afterglow is detected in the first white and u exposures at a refined UVOT position RA(J2000)= 193.89625 deg, DEC(J2000) = 28.06503, which is: RA (J2000) 12:55:35.10 Dec (J2000) 28:03:54.1 with an estimated uncertainty of 1.3 arcsec (radius, 90% confidence). This position is consistent with the optical afterglow detection by NOT (de Ugarte Postigo., GCN Circ 11605) and the enhanced XRT position (Osborne et al., GCN Circ. 11606). Preliminary magnitudes using the UVOT photometric system (Poole et al. 2008, MNRAS, 383, 627) for single and summed exposures are: Filter T_start(s) T_stop(s) Exp(s) Mag/3sigUL ##################################################### wh (FC) 144 294 147 20.98 +/- 0.29 u (FC) 302 552 246 20.32 +/- 0.35 wh 582 6352 580 > 21.89 v 632 6763 432 > 20.09 u 707 5943 412 > 20.95 b 558 6148 432 > 21.32 uvw1 682 5738 221 > 20.34 uvm2 658 6874 340 > 20.43 uvw2 608 6558 393 > 20.88 ##################################################### The values quoted above are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.01 in the direction of the burst (Schlegel et al. 1998). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 11613 SUBJECT: GRB 110128A: TAROT-Calern refined analysis DATE: 11/01/28 15:49:13 GMT FROM: Bruce Gendre at ASDC Laas-Bourez M. (UWA/ICRAR), Gendre B. (ASDC), Atteia J.L. (IRAP-OMP), Klotz A. (IRAP-OMP), and Boer M. (OHP-OAMP) report: following the detection of the optical afterglow by de Ugarte Postigo et al. (GCN 11605), we re-analyzed the TAROT data reported in Klotz et al. (GCN 11604). At the position of the afterglow, an object is marginally detected (2.6 sigma confidence level) within the stack of the first two images (73.7s -> 178.6s), with R = 18.0. A stack of the following 4 images (193.7s -> 359.2s) gave only an upper limit of R < 18.7. Combined with the NOT observation, this gives an optical decay index of at least 1.6 during the initial part of the light curve, that could indicate the presence of a reverse shock. Magnitudes were estimated with the nearby USNO-B1 stars and are not corrected for galactic dust extinction. This message can be cited ---------------------------------------------------------------- This message was sent using IMP, the Internet Messaging Program. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 11614 SUBJECT: GRB 110128A, Swift-BAT refined analysis DATE: 11/01/28 17:04:11 GMT FROM: Hans Krimm at NASA-GSFC J. R. Cummings (GSFC/UMBC), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), E. E. Fenimore (LANL), N. Gehrels (GSFC), D. Grupe (PSU), H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (GSFC/UMBC), G. Sato (ISAS), M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (GWU) (i.e. the Swift-BAT team): Using the data set from T-240 to T+962 sec from the recent telemetry downlink, we report further analysis of BAT GRB 110128A (trigger #443861) (Grupe, et al., GCN Circ. 11603). The BAT ground-calculated position is RA, Dec = 193.871, 28.108 deg which is RA(J2000) = 12h 55m 29.0s Dec(J2000) = +28d 06' 28.7" with an uncertainty of 2.3 arcmin, (radius, sys+stat, 90% containment). The partial coding was 37%. The mask-weighted light curve shows a single broad peak extending from approximately T-3 sec to T+40 sec. T90 (15-350 keV) is 30.7 +- 18.1 sec (estimated error including systematics). The time-averaged spectrum from T-1.4 to T+48.3 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.31 +- 0.30. The fluence in the 15-150 keV band is 7.2 +- 1.4 x 10-7 erg/cm2. The 1-sec peak photon flux measured from T+3.58 sec in the 15-150 keV band is 0.8 +- 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/443861/BA/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 11615 SUBJECT: GRB110128A: TNG NIR observations DATE: 11/01/28 20:16:21 GMT FROM: Angelo Antonelli at Obs. Astro. di Roma L.A. Antonelli (INAF-OAR), P. D'Avanzo (INAF-OAB), D. Malesani (DARK/ NBI), V. Lorenzi, G. Tessicini (INAF-TNG) and E. Palazzi (INAF-IASF/ Bo) on behalf of the CIBO collaboration report: "We observed the field of GRB 110128A (Grupe et al. GCN 11603) in the J band with the 3.6m TNG equipped with the NICS camera. A total of 15 min integration were obtained with a mean time Jan 28.254 UT (4.37 hr after the GRB). A faint, close to the detection limit, NIR source is detected in our image at the position of the optical afterglow reported by de Ugarte Postigo et al. (GCN 11605). The source has a magnitude J = 21.8+/-0.4 (calibrated against the 2MASS stars in the field). Being the coincident with the optical afterglow we conclude that it is the NIR counterpart of the GRB 110128A afterglow. This message can be cited" //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 11618 SUBJECT: GRB110128A: MITSuME Okayama optical upper limits DATE: 11/01/29 09:18:32 GMT FROM: Daisuke Kuroda at OAO/NAOJ D. Kuroda, K. Yanagisawa, Y. Shimizu, H. Toda (OAO, NAOJ), S. Nagayama (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 110128A (Grupe et al., GCN 11603) with the optical three color (g', Rc and Ic) CCD camera attached to the MITSuME 50cm telescope of Okayama Astrophysical Observatory. The observation started on 2011-01-28 14:44:10 UT (~13 hours after the burst). We did not find any new point source within the enhanced XRT error circle (Osborne et al., GCNC 11606) and could not detect the previously reported afterglow (de Ugarte Postigo et al., GCN 11605) 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 ------------------------------------------------------ 0.63108 16:53:18 6300.0 >20.6 >20.3 >19.8 ------------------------------------------------------ T0+ : Elapsed time after the burst [day] T-EXP: Total Exposure time [sec] //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 11628 SUBJECT: GRB 110128A: Fermi GBM detection DATE: 11/02/03 17:21:00 GMT FROM: Vandiver Chaplin at UAH/Fermi-GBM V.Chaplin (UAH) reports on behalf of the Fermi GBM Team: "At 01:44:36 UT on 28 January 2011, the Fermi Gamma-ray Burst Monitor (GBM) triggered on located GRB 110128A (trigger 317871878 /110128.073). This burst also triggered Swift,BAT (Grupe et al., GCN 11603). The GBM on-ground calculated location is consistent with the Swift position. The Swift localization had an angle of 45 degrees from the LAT boresight at the GBM trigger time. The GBM light curve shows a single pulse with a duration (T90) of about 12 s (50-300 keV) from approximately T0-5.8 s. The time-averaged spectrum from T0-8 to T0+6 s is best fit by a simple power-law with index is -1.5 +/-0.1. The 1-sec peak flux in the band 10-1000 keV and starting at time T0-2 s is 1.6 +/- 0.2 ph/s-cm^2. The fluence (10-1000 keV) in this time interval is (1.5 +/- 0.2)E-06 erg/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."