//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 5675 SUBJECT: GRB 061002: Swift detection of a burst DATE: 06/10/02 01:34:04 GMT FROM: Scott Barthelmy at NASA/GSFC J, K. C. Cannizzo (NASA/UMBC), S. D. Barthelmy (GSFC), A. P. Beardmore (U Leicester), J. R. Cummings (NASA/UMBC), S. D. Hunsberger (PSU), F. E. Marshall (NASA/GSFC), K. M. McLean (LANL/UTD), K. L. Page (U Leicester), D. M. Palmer (LANL) and M. Stamatikos (NASA/ORAU) report on behalf of the Swift Team: At 01:03:29 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 061002 (trigger=231974). Swift slewed immediately to the burst. The BAT on-board calculated location is RA,Dec 220.346, +48.736 {14h 41m 23s, +48d 44' 11"} (J2000) 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 ~500 counts/sec (15-350 keV), at ~5 sec after the trigger. The XRT began taking data at 01:05:41 UT, 132 seconds after the BAT trigger. The XRT on-board centroid algorithm did not find a source in the image, but ground analysis reveals a faint, probably fading source at RA, Dec = 14h 41m 23.62s, +48d 44' 23.4" (J2000) with an estimated uncertainty of 15 arcsec radius (90% containment). This is 14.9 arcsec from the BAT position. UVOT took a finding chart exposure of 400 seconds with the V filter starting 128 seconds after the BAT trigger. No afterglow candidate has been found in the initial data products. The 2.7'x2.7' sub-image covers 25% of the BAT error circle and 100% of the XRT error circle. The 3-sigma upper limit is about 19.0 mag. The 8'x8'region for the list of sources generated on-board covers 100% of the BAT error circle. No correction has been made for the expected extinction of about 0.1 magnitudes. ---APPENDED NEW UVOT PARAGRAPH--- UVOT took a finding chart exposure of 400 seconds with the V filter starting 128 seconds after the BAT trigger. No afterglow candidate has been found in the initial data products. The 2.7'x2.7' sub-image covers 25% of the BAT error circle. The typical 3-sigma upper limit has been about 18.5 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 18.0 mag. No correction has been made for the expected extinction of about 0.1 magnitudes. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 5676 SUBJECT: GRB 061002: Swift detection of a burst: CORRECTED CONTENT DATE: 06/10/02 01:41:46 GMT FROM: Scott Barthelmy at NASA/GSFC J. K. Cannizzo (NASA/UMBC), S. D. Barthelmy (GSFC), A. P. Beardmore (U Leicester), J. R. Cummings (NASA/UMBC), S. D. Hunsberger (PSU), F. E. Marshall (NASA/GSFC), K. M. McLean (LANL/UTD), K. L. Page (U Leicester), D. M. Palmer (LANL) and M. Stamatikos (NASA/ORAU) report on behalf of the Swift Team: This is the corrected circular (no extra UVOT paragraph plus a slight change to the 3-sigma upper limit: 18.7). At 01:03:29 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 061002 (trigger=231974). Swift slewed immediately to the burst. The BAT on-board calculated location is RA,Dec 220.346, +48.736 {14h 41m 23s, +48d 44' 11"} (J2000) 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 ~500 counts/sec (15-350 keV), at ~5 sec after the trigger. The XRT began taking data at 01:05:41 UT, 132 seconds after the BAT trigger. The XRT on-board centroid algorithm did not find a source in the image, but ground analysis reveals a faint, probably fading source at RA, Dec = 14h 41m 23.62s, +48d 44' 23.4" (J2000) with an estimated uncertainty of 15 arcsec radius (90% containment). This is 14.9 arcsec from the BAT position. UVOT took a finding chart exposure of 400 seconds with the V filter starting 128 seconds after the BAT trigger. No afterglow candidate has been found in the initial data products. The 2.7'x2.7' sub-image covers 25% of the BAT error circle and 100% of the XRT error circle. The 3-sigma upper limit is about 18.7 mag. The 8'x8' region for the list of sources generated on-board covers 100% of the BAT error circle. No correction has been made for the expected extinction of about 0.1 magnitudes. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 5677 SUBJECT: GRB061002: MASTER-VWF-Kislovodsk observations DATE: 06/10/02 03:09:28 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V. Lipunov, V.Kornilov, A.Belinski, N.Shatskiy, E.Gorbovskoy,D.Kuvshinov, N.Tyurina, P.Gritsyk Sternberg Astronomical Institute, Moscow Union 'Optic' I.Golubov Kislovodsk Solar Station of the Pulkovo observatory "MASTER Very Wide Filed Camera located at Kislovodsk Solar Station (http://observ.pereplet.ru, D=70 mm, 400 square degrees) has moved to the Swift-BAT trigger 231974 and it has taken a series of 5s exposures starting 97s after the GRB Time at 01:05:07 UT under good weather condition. The limiting magnitude is 12.0m (unfiltered) for single exposures and 13.0m for the sum of 20 images. Sum of 10 images: http://pereplet.sai.msu.ru/nauka/spy_sum10.jpg Reduction in contining. The message may be cited. mailto: lipunov@sai.msu.ru //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 5678 SUBJECT: GRB 061002, Swift-BAT refined analysis DATE: 06/10/02 04:03:31 GMT FROM: Scott Barthelmy at NASA/GSFC D. Hullinger (BYU-Idaho), L. Barbier (GSFC), S. D. Barthelmy (GSFC), J. K. Cannizzo (NASA/UMBC), J. Cummings (GSFC/UMBC), E. Fenimore (LANL), N. Gehrels (GSFC), H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD), D. Palmer (LANL), A. Parsons (GSFC), T. Sakamoto (GSFC/ORAU), G. Sato (GSFC/ISAS), M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC) on behalf of the Swift-BAT team: Using the data set from T-239 to T+303 sec from the recent telemetry downlink, we report further analysis of BAT GRB 061002 (trigger #231974) (Cannizzo, et al., GCN Circ. 5676). The BAT ground-calculated position is RA,Dec = 220.356, 48.726 deg {14h 41m 25.4s, 48d 43' 32.0"} (J2000) +- 1.7 arcmin, (radius, sys+stat, 90% containment). The partial coding was 39%. The mask-weighted lightcurve has a single roughly triangular shaped peak starting at T-10 sec, peaking at T+10 sec, and ending at T+60 sec. There is one caveate to this in that there is a 20-sec gap in the downliked data starting at T+160 sec. T90 (15-350 keV) is 17.6 +- 1 sec (estimated error including systematics). The time-averaged spectrum from T-2.3 to T+16.9 is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.76 +- 0.21. The fluence in the 15-150 keV band is 6.8 +- 0.8 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from T-1.38 sec in the 15-150 keV band is 0.8 +- 0.3 ph/cm2/sec. All the quoted errors are at the 90% confidence level. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 5679 SUBJECT: GRB061002 - SDSS Pre-Burst Observations DATE: 06/10/02 04:09:58 GMT FROM: Richard J. Cool at U.of AZ/Steward Obs Richard J. Cool (Arizona), Daniel J. Eisenstein (Arizona), David W. Hogg (NYU), Michael R. Blanton (NYU), David J. Schlegel (LBNL), J. Brinkmann (APO), Donald Q. Lamb (Chicago), Donald P. Schneider (PSU), and Daniel E. Vanden Berk (PSU) report: The Sloan Digital Sky Survey (SDSS) imaged the field of burst GRB061002 prior to the burst. As these data should be useful as a pre-burst comparison and for calibrating photometry, we are supplying the images and photometry measurements for this GRB field to the community. Data from the SDSS, including 5 FITS images, 3 JPGS, and 3 files of photometry and astrometry, are being placed at http://mizar.as.arizona.edu/~grb/public/GRB061002 We supply FITS images in each of the 5 SDSS bands of a 8'x8' region centered on the GRB position (ra=220.346 (14:41:23.0), dec=48.7360 (48:44:09.6); BAT Trigger 231974), as well as 3 gri color-composite JPGs (with different stretches). The units in the FITS images are nanomaggies per pixel. A pixel is 0.396 arcsec on a side. A nanomaggie is a flux-density unit equal to 10^-9 of a magnitude 0 source or, to the extent that SDSS is an AB system, 3.631e-6 Jy. The FITS images have WCS astrometric information. In the file GRB061002_sdss.calstar.dat, we report photometry and astrometry of 226 bright stars (r<20.5) within 15' of the burst location. The magnitudes presented in this file are asinh magnitudes as are standard in the SDSS (Lupton 1999, AJ, 118, 1406). Beware that some of these stars are not well-detected in the u-band; use the errors and object flags to monitor data quality. In the files GRB061002_sdss.objects_flux.dat and GRB061002_sdss.objects_magnitudes.dat, we report photometry of 371 objects detected within 6' of the GRB position. We have removed saturated objects and objects with model magnitudes fainter than 23.0 in the r-band. The fluxes listed in GRB061002_sdss.objects_flux.dat are in nanomaggies while the magnitudes listed in GRB061002_sdss.objects_magnitudes.dat are asinh magnitudes. All quantities reported are standard SDSS photometry, meaning that they are very close to AB zeropoints and magnitudes are quoted in asinh magnitudes. Photometric zeropoints are known to about 2% rms. None of the photometry is corrected for dust extinction. The Schlegel, Finkbeiner, and Davis (1998) predictions for this region are A_U=0.223 mag, A_g=0.164 mag, A_r = 0.119 mag, A_i=0.090 mag, and A_z=0.064 mag. There are currently no objects within 6 arcminutes of the GRB position in the SDSS spectroscopic database. SDSS astrometry is generally better than 0.1 arcsecond per coordinate. Users requiring high precision astrometry should take note that the SDSS astrometric system can differ from other systems such as those used in other notices; we have not checked the offsets in this region. More detailed information pertaining to our SDSS GRB releases can be found in our initial data release paper (Cool et al. 2006, astro-ph/0601218). See the SDSS DR4 documentation for more details: http://www.sdss.org/dr5. These data have been reduced using a slightly different pipeline than that used for SDSS public data releases. We cannot guarantee that the values here will exactly match those in the data release in which these data are included. In particular, we expect the photometric calibrations to differ by of order 0.01 mag. This note may be cited, but please also cite the SDSS data release paper, Adelman-McCarthy et al. (2006, ApJS, 162, 38), when using the data or referring to the technical documentation. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 5681 SUBJECT: GRB 061002: Swift-XRT Team Refined Analysis DATE: 06/10/02 08:02:37 GMT FROM: Kim Page at U.of Leicester K.L. Page (U. Leicester) and J.K. Cannizzo (NASA/UMBC) report on behalf of the Swift-XRT team: We have analysed the first 3 orbits of GRB 061002 data obtained by the Swift-XRT. Using the 4.5 ks of Photon Counting data from the second and third orbits (the first orbit of data was entirely in Windowed Timing mode), we find a refined position of: RA(J2000) = 14 41 23.29 Dec(J2000) = +48 44 30.5 with an estimated uncertainty of 7.5 arcsec (90% confidence, including boresight uncertainties). This lies 7.8 arcsec from the initial XRT position given by Cannizzo et al. in GCN Circ. 5675, and 60.7 arcsec from the ground-calculated BAT position (GCN Circ. 5678; Hullinger et al.) The X-ray light-curve shows a break from a steep decay slope of alpha_1 = 2.97 +/- 0.31 to alpha_2 = 1.25 +/- 0.12 at about 304 seconds after the trigger. The Windowed Timing spectrum can be modelled by a power-law with a column density in excess of the Galactic value in that direction. The fit parameters are: Gamma = 2.19 +0.36/-0.31 and NH_excess = (1.5 +0.8/-0.7)e21 cm^-2 (in addition to NH_Galactic = 2.07e20 cm^-2). The mean observed (unabsorbed) flux over this first orbit (138-1345s after the burst) was found to be 1.24e-11 (1.90e-11) erg cm^-2 s^-1. If the decay continues at a rate of alpha = 1.25, the estimated count rate at 24 hours will be 4.1e-4 count s^-1, corresponding to an observed (unabsorbed) flux of 1.86e-14 (2.79e-14) erg cm^-2 s^-1. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 5683 SUBJECT: GRB061002: Swift UVOT followup observations DATE: 06/10/02 12:35:13 GMT FROM: Alice Breeveld at MSSL-UCL A. Breeveld (MSSL/UCL) and J. Cannizzo (NASA/UMBC) report on behalf of the Swift/UVOT team: The Swift/UVOT began taking data on 2006-10-02, 129s after the burst (Cannizzo et al., GCN 5676), discounting the 10s settling image. At the position of the XRT error circle (Page et al., GCN 5681) there are no new sources. In the summed UVOT images we obtain the following 3 sigma upper limits: Filter T_range(s) Exp(s) 3-sig UL (mag) v 129-7107 1283 20.32 b 607-6697 412 20.63 u 582-12911 1095 20.87 w1 559-12244 1337 21.11 m2 534-11337 1354 21.41 w2 622-6902 432 21.19 These magnitudes are not corrected for the expected extinction of E(B-V)=0.046