//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 13408 SUBJECT: GRB 120703A: Swift detection of a bright burst with an optical afterglow DATE: 12/07/03 17:34:05 GMT FROM: David Palmer at LANL B.-B. Zhang (PSU), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), D. N. Burrows (PSU), M. M. Chester (PSU), N. Gehrels (NASA/GSFC), D. Grupe (PSU), F. E. Marshall (NASA/GSFC), D. M. Palmer (LANL), J. L. Racusin (NASA/GSFC) and T. N. Ukwatta (MSU) report on behalf of the Swift Team: At 17:25:22 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 120703A (trigger=525671). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 339.357, -29.736 which is RA(J2000) = 22h 37m 26s Dec(J2000) = -29d 44' 08" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a multiply-peaked structure with a duration of about 50 sec. The peak count rate was ~14000 counts/sec (15-350 keV), at ~0 sec after the trigger. The XRT began observing the field at 17:26:48.9 UT, 86.7 seconds after the BAT trigger. Using promptly downlinked data we find an uncatalogued X-ray source located at RA, Dec 339.35607, -29.72444 which is equivalent to: RA(J2000) = 22h 37m 25.46s Dec(J2000) = -29d 43' 28.0" with an uncertainty of 3.8 arcseconds (radius, 90% containment). This location is 41 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 (1.21 x 10^20 cm^-2, Kalberla et al. 2005), with an excess column of 3.5 (+1.97/-1.72) x 10^21 cm^-2 (90% confidence). UVOT took a finding chart exposure of 150 seconds with the White filter starting 91 seconds after the BAT trigger. There is a candidate afterglow in the list of sources generated on-board at RA(J2000) = 22:37:25.71 = 339.35711 DEC(J2000) = -29:43:23.5 = -29.72320 with a 90%-confidence error radius of about 1.10 arc sec. This position is 5.5 arc sec. from the center of the XRT error circle. The estimated magnitude is 18.51. No correction has been made for the expected extinction corresponding to E(B-V) of 0.02. Burst Advocate for this burst is B.-B. Zhang (bbzhang AT 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: 13411 SUBJECT: GRB 120703A: NOT optical observation DATE: 12/07/04 07:56:33 GMT FROM: Dong Xu at Weizmann Inst D. Xu (WIS), D. Malesani, J. P. U. Fynbo (DARK/NBI), N. R. Tanvir (U. Leicester), K. Karhunen (U. Turku) report on behalf of a larger collaboration, We observed the field of GRB 120703A (Zhang et al., GCN 13408) using the 2.5m Nordic Optical Telescope (NOT) equipped with StanCam. Observations started at 04:02:42 UT on 2012-07-04 (i.e., 10.62 hr after the BAT trigger) and 6x300s R-band frames were obtained. An optical source was marginally detected in the stacked image at coordinates RA (J2000) = 22:37:25.61 Dec (J2000) = -29:43:23.7 with an uncertainty of ~0.5 arcsec radius, being consistent, but slightly offset, with the UVOT position. The source had R~21.7 calibrated against nearby USNO star. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 13412 SUBJECT: Konus-Wind observation of GRB 120703A DATE: 12/07/04 07:58:07 GMT FROM: Dmitry Frederiks at Ioffe Institute S. Golenetskii, R.Aptekar, D. Frederiks, E. Mazets, V. Pal'shin, P. Oleynik, M. Ulanov, D. Svinkin, and T. Cline on behalf of the Konus-Wind team, report: The long GRB 120703A (Swift-BAT trigger #525671: B.-B. Zhang et al., GCN 13408) triggered Konus-Wind at T0=62723.578s UT (17:25:23.578) The burst light curve shows a single peak with a total duration of ~12.5 s. The emission is seen up to ~7 MeV. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB120703_T62723/ As observed by Konus-Wind the burst had a fluence of (7.7 ± 1.0)x10-6 erg/cm2, and a 64-ms peak flux, measured from T0+0.960 s, of (5.4 ± 1.3)x10-6 erg/cm2/s (both in the 20 keV - 10 MeV energy range). The time-integrated spectrum of the burst (measured from T0 to T0+8.448 s) is well fit in the 20 keV - 10 MeV range by a power law with exponential cutoff model, for which: alpha = -0.81 (-0.25, +0.30), and Ep = 295(-56, +88) keV, chi2 = 96.8/84 dof. Fitting this spectrum with the GRB (Band) function yields the following model parameters: the low-energy photon index alpha = -0.67 (-0.37, +0.54), the high energy photon index beta = -2.7 (<-2.3), the peak energy Ep = 256(-75, +100) keV, chi2 = 96.4/83 dof. The spectrum at the maximum count rate (measured from T0 to T0+0.256 s) is best fitted is best fit in the 20 keV - 10 MeV range by a power law with exponential cutoff model, for which: alpha = -0.50 (-0.37, +0.46), and Ep = 410(-90, +150) keV, chi2 = 21.5/22 dof. All the quoted results are preliminary. All the quoted errors are at the 90% confidence level. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 13414 SUBJECT: GRB 120703A: Swift-BAT refined analysis DATE: 12/07/04 13:10:16 GMT FROM: Scott Barthelmy at NASA/GSFC M. Stamatikos (OSU), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC), E. E. Fenimore (LANL), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (GSFC/UMBC), G. Sato (ISAS), J. Tueller (GSFC), T. N. Ukwatta (MSU), B.-B. Zhang (PSU) (i.e. the Swift-BAT team): Using the data set from T-61 to T+243 sec from recent telemetry downlinks, we report further analysis of BAT GRB 120703A (trigger #525671) (Zhang, et al., GCN Circ. 13408). The BAT ground-calculated position is RA, Dec = 339.353, -29.726 deg, which is RA(J2000) = 22h 37m 24.7s Dec(J2000) = -29d 43' 34.9" with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment). The partial coding was 50%. The mask-weighted light curve shows the burst started at ~T-45 sec with a weak pulse with a width of about 20 sec. The burst continues with a moderate increase to a strong central pulse from T-0.2 to T+1.0 sec, and then a decay back to baseline at ~T+45 sec. T90 (15-350 keV) is 25.2 +- 4.3 sec (estimated error including systematics). The time-averaged spectrum from T-7.27 to T+32.60 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.51 +- 0.06. The fluence in the 15-150 keV band is 3.5 +- 0.1 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T+0.06 sec in the 15-150 keV band is 10.5 +- 0.4 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/525671/BA/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 13415 SUBJECT: GRB 120703A: Enhanced Swift-XRT position DATE: 12/07/04 23:24:19 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 7867 s of XRT Photon Counting mode data and 16 UVOT images for GRB 120703A, 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 = 339.35690, -29.72350 which is equivalent to: RA (J2000): 22h 37m 25.66s Dec (J2000): -29d 43' 24.6" with an uncertainty of 1.4 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: 13416 SUBJECT: GRB 120703A: Swift-XRT refined Analysis DATE: 12/07/04 23:34:04 GMT FROM: Phil Evans at U of Leicester J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), C. Pagani (U. Leicester), A. Melandri (INAF-OAB), B. Sbarufatti (INAF-OAB/PSU), G. Stratta (ASDC), J.A. Kennea (PSU), M.C. Stroh (PSU), D.N. Burrows (PSU) and B.-B. Zhang report on behalf of the Swift-XRT team: We have analysed 12 ks of XRT data for GRB 120703A (-B. Zhang et al. GCN Circ. 13408), from 70 s to 68.9 ks after the BAT trigger. The data comprise 374 s in Windowed Timing (WT) mode (the first 9 s were taken while Swift was slewing) with the remainder in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Goad et al. (GCN. Circ 13415). The light curve can be modelled with an initial power-law decay with an index of alpha=0.69 (+0.04, -0.06), followed by a break at T+4130 s to an alpha of 1.04 (+/-0.06). A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 2.00 (+0.13, -0.12). The best-fitting absorption column is 1.4 (+/-0.3) x 10^21 cm^-2, in excess of the Galactic value of 1.2 x 10^20 cm^-2 (Kalberla et al. 2005). The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 3.7 x 10^-11 (5.1 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 1.4 (+/-0.3) x 10^21 cm^-2 Galactic foreground: 1.2 x 10^20 cm^-2 Excess significance: 7.0 sigma Photon index: 2.00 (+0.13, -0.12) The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00525671. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 13417 SUBJECT: GRB 120703A: Fermi GBM detection DATE: 12/07/05 02:29:05 GMT FROM: Andrew Collazzi at NASA/MSFC/ORAU Andrew C. Collazzi (NASA/ORAU) reports on behalf of the Fermi GBM Team: "At 17:25:17 UT on 03 July 2012, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 120703A (trigger 363029120 / 120703.726). This burst was also detected by Swift/BAT (Zhang, B.-B. et al., GCN 13408). The GBM on-ground position is consistent with the Swift location. The burst was also detected by Konus-Wind (Golenetskii, R. et al., GCN 13412). The burst triggered an ARR (Automatic Repointing Request), causing Fermi to slew so the LAT would point to the source. The GBM light curve is similiar to the Swift detection. We observe a strong central pulse with fainter wings, the total pulse having a width of ~20s. We measure the duration (T90) of about 9.216s (50-300 keV). The time-averaged spectrum from T0-2.048 to T0+14.336 s is best fit by a Comptonized power-law function, with Epeak = 305.6 +/- 21.1 keV and alpha = -1.06 +/- 0.03. The fluence (10-1000 keV) in this time interval is (9.154 +/- 0.246)E-06 erg/cm^2. The burst is also fit well with a Band function with Epeak = 238.5 +/- 26.5, keV alpha = -0.98 +/- 0.05, and beta = -2.08 +/- 0.12. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog." //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 13418 SUBJECT: GRB 120703A: Swift/UVOT Detection DATE: 12/07/05 14:00:15 GMT FROM: Craig Swenson at PSU/Swift C. A. Swenson (PSU) and B.-B. Zhang (PSU) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 120703A 90 s after the BAT trigger (Zhang et al., GCN Circ. 13408). A source consistent with the XRT position (Goad et al., GCN Circ. 13415) is detected in the initial UVOT exposures. The preliminary UVOT position is: RA (J2000) = 22:37:25.67 = 339.35694 (deg.) Dec (J2000) = -29:43:23.8 = -29.72327 (deg.) with an estimated uncertainty of 0.52 arc sec. (radius, 90% confidence). Preliminary detections and 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the early exposures are: Filter T_start(s) T_stop(s) Exp(s) Mag white 90 240 147 18.48 ± 0.06 v 4299 4499 197 >19.5 b 3684 5249 325 >20.9 u 304 416 110 18.07 ± 0.13 w1 4710 4909 197 >19.5 m2 4504 4704 197 >21.4 w2 4095 4294 197 >21.4 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.02 in the direction of the burst (Schlegel et al. 1998). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 13420 SUBJECT: GRB 120703A: SMARTS optical/IR observations DATE: 12/07/05 20:54:45 GMT FROM: Bethany Cobb at GWU B. E. Cobb (GWU) reports: Using the ANDICAM instrument on the 1.3m telescope at CTIO, we obtained optical/IR imaging of the error region of GRB 120703A (GCN 13408, Zhang et al.) with a mid-exposure time of 13.7 hours post-burst (2012-07-04 07:07 UT). Total summed exposure times amounted to 15 minutes in I and V and 12 minutes in J and K. No source is detected at the position of the optical afterglow (e.g. GCN 13411, Xu et al.; GCN 13418, Swenson et al.) to approximate limiting magnitudes of I > 20.5, J > 18.5 and K > 17.4. Magnitudes are calibrated using USNO-B1.0 stars in I, and 2MASS stars in J and K.