//////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3509 SUBJECT: Swift/BAT Detection of GRB050603 DATE: 05/06/03 08:11:03 GMT FROM: David Palmer at LANL A. Retter (PSU), A. Parsons, N. Gehrels (GSFC), C. Gronwall (PSU), C. B. Markwardt (GSFC/UMD), D. Palmer (LANL) on behalf of the Swift Team report: At 06:29:05 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB050603 (trigger=131560). The BAT on-board calculated location is RA,Dec 39.978 (+02h 39m 55s), -25.183 (-25d 10' 57") (J2000) with an uncertainty of 4 arcmin (radius, 3-sigma, including estimated systematic uncertainty). The peak rate was 22,000 counts/sec in 0.512 sec in the 50 - 350 keV band. The Swift spacecraft did not slew because automated slewing was not enabled due to engineering tests. XRT and UVOT observations will be performed after the analysis of the ground data. This burst is near the edge of the FOV (~8% coding) and so it is brighter than indicated by the nominal peak count rate. No light curves will be available until the next Malindi ground contact data is received and analyzed. However, during the approximately 7 seconds of image processing, no subsequent interval was found with a more significant rate increase than the initial 0.512 s trigger (although further emission at lower levels is not precluded by the data available at this time.) Thus preliminary indications suggest that this might be a bright short-hard burst. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3510 SUBJECT: GRB 050603: INTEGRAL shows it is not a short GRB DATE: 05/06/03 08:56:11 GMT FROM: Diego Gotz at IASF-CNR D. Gotz and S. Mereghetti (IASF, Milano) on behlaf of the IBAS Localization Team report: GRB 050603 (Retter et al., GCN 3509) has been detected also by the IBIS instrument on board INTEGRAL in the 40-300 keV energy band. Being outside of the field of view of the instrument, this burst cannot be localized. The burst starts at 2005-06-03T06:29:03 UT and has a multipeaked light curve, showing at least 3 distinct peaks, with the last one being the brightest. The GRB lasts 10 s, so it does not belog to the short class. This message can be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3511 SUBJECT: GRB 050603: Afterglow Identification from LCO DATE: 05/06/03 11:01:08 GMT FROM: Edo Berger at Carnegie Obs Edo Berger and Andy McWilliam (Carnegie Observatories) report: "On 2005, June 3.412 UT (3.4 hrs after the burst) we imaged the BAT error circle of GRB 050603 (GCN 3509) with the du Pont 100-inch telescope at Las Campanas Observatory in the R-band. Within the 4' radius error circle we find a single bright source (R~16.5 mag) which is not present in the DSS at coordinates (J2000): RA = 02:39:57 DEC=-25:10:54 with an uncertainty of about 0.5" in each coordinate. At the present we do have information about variability." //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3512 SUBJECT: GRB 050603: Swift-BAT refined analysis of a long three-spiked burst DATE: 05/06/03 11:38:08 GMT FROM: David Palmer at LANL E. Fenimore (LANL), L. Angelini (GSFC-JHU)L. Barbier (GSFC), S. Barthelmy (GSFC), J. Cummings (GSFC/NRC), N. Gehrels (GSFC), J. Greiner (MPE), D. Hullinger (UMD), H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD), D. Palmer (LANL), A. Parsons (GSFC), A. Retter (PSU) T. Sakamoto (GSFC/NRC), G. Sato (ISAS), M. Suzuki (Saitama), J. Tueller (GSFC) on behalf of the Swift/BAT team: At 06:29:05.2 UT, Swift-BAT detected GRB 050603 (trigger=131560) (GCN Circ 3509, Retter et al.). The refined BAT ground position is (RA,Dec) = 39.982,-25.195, [deg; J2000] {02:39:56; -25:11:41} (~1 arcminute statistical and systematic error radius, 95% containment). This is about 45 arcseconds from the on-board derived position. This source was near the edge of the field of view, 41 degrees from the boresight in the short direction, directly illuminating only 9% of the detector array. The mask-weighted lightcurve of the burst shows three fast-rise-exponential-decay (FRED) spikes, peaking at T-2.7, T-0.85 and T+0.15 with each spike having a width of ~0.6 s (FWHM). The third spike is ~3x the height of each of the first two spikes and produced the original image detection. Additional tail emission continues to decay after the third spike, extending to T+10. The photon index of the time-averaged spectrum is well-fit over the 15-350 keV energy band by a power law of index 1.22 +/- 0.06 with a normalization at 50 keV of (2.96 +/- 0.10) x 10^-2 photons/s/cm^2/keV. The fluence in the 15-350 keV band is 1.30 x 10^-5 erg/cm^2. The peak flux is 31.8+/1.7 photons/cm^2/s for the 1 second interval starting at T-0.18 s. Due to the current engineering mode of the spacecraft, XRT and UVOT observations will be delayed until a Target Of Opportunity pointing is manually commanded. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3513 SUBJECT: GRB050603: Radio Detection DATE: 05/06/03 19:32:18 GMT FROM: Patrick B. Cameron at Caltech P. B. Cameron (Caltech) reports on behalf of the Caltech-NRAO-Carnegie GRB Collaboration: "We observed the field of GRB050603 (GCN#3509) using the Very Large Array at a frequency of 8.5 GHz on June 3.62 UT. We detect a radio source with coordinates (J2000) Ra= 02:39:56.891 Dec= -25:10:54.6 with an uncertainty of 0.1" in each coordinate at the position of the optical afterglow (GCN#3511)." //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3514 SUBJECT: GRB 050603: Swift XRT Position DATE: 05/06/03 20:10:04 GMT FROM: Judith Racusin at PSU J. L. Racusin, D. N. Burrows, J. A. Kennea, A. Retter (PSU), C. Pagani (INAF-OAB), A. Wells (U. Leicester), N. Gehrels (NASA/GSFC) report on behalf of the Swift XRT team: The Swift BAT detected GRB 050603 at 06:29:05.2 UT on June 3rd 2005 (GCN 3509, Retter et al.). The Swift observatory did not slew promptly because automated slewing was not enabled due to engineering tests. The XRT began taking data at 17:19:27 UT, approximately 11 hours after the trigger. In a preliminary data analysis we detect an uncataloged X-ray source located at: RA(J2000) = 2:39:56.6, Dec(J2000) = -25:10:52.5 We estimate an uncertainty of 8 arcseconds radius (90% containment). This position is 51 arcseconds from the BAT refined position reported by Fenimore et al. (GCN 3512), 5.6 arseconds from the optical afterglow candidate reported by Berger et al. (GCN 3511), and 4.5 arcseconds from the radio afterglow candidate reported by Cameron et al. (GCN 3513). Observations are still underway and further ground analysis will be performed to determine if this X-ray source is fading. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3515 SUBJECT: GRB050603, submillimetre observations DATE: 05/06/03 20:23:59 GMT FROM: Vicki Barnard at Joint Astro.Centre,Hawaii V. Barnard, G. Schieven, R. Tilanus, E. Lundin (all Joint Astronomy Centre), R. Ivison (Astronomy Technology Centre, Royal Observatory Edinburgh) report on behalf of the JCMT afterglow collaboration: We have observed the field of the afterglow of GRB050603 as reported in GCN 3511 with SCUBA at the JCMT. SCUBA operates simultaneously at 450 and 850 microns and has a field of view of approximately 2.3 arcmin. In moderate weather conditions, the initial results are: 850 micron: 2.408 +/- 1.973 mJy 450 micron: -41.97 +/- 94.988 mJy These observations began at 20050603.738 UT and ended at 20050603.823 UT. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3516 SUBJECT: GRB050603: Fading Afterglow observed by Swift UVOT DATE: 05/06/03 21:21:19 GMT FROM: Patricia Schady at MSSL/Swift P. Brown (PSU), A. Retter (PSU), P. Schady (MSSL), P. Roming (PSU), C. Gromwall (PSU), N. Cucchiara (PSU), P. Boyd (GSFC), K. Mason (MSSL), N. Gehrels (GSFC), on behalf of the Swift UVOT team The Swift Ultra-Violet/Optical Telescope (UVOT) began observations of GRB050603 on June 3, 2005 at 15:42:59 UT, ~9 hours after the initial Swift BAT trigger (Retter et al, GCN 3509). The observations were delayed because automated slewing was not enabled during engineering tests at the time of the burst. A fading source is detected in the V band at the afterglow position first reported by Berger & McWilliam (GCN 3511). The coordinates of this source are Ra, Dec = 02:39:56.839, -25:10:54.92 Astrometry was performed using reference stars from the GSC. Magnitudes from the two long exposures are as follows: Filter Magnitude Duration(s) T_start(s) V 18.2 +/- 0.12 1298 32997 V 21.8 +/- 0.4 2103 38782 //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3517 SUBJECT: GRB 050603: Analysis of UVOT data DATE: 05/06/03 23:18:24 GMT FROM: Edo Berger at Carnegie Obs E. Berger (Carnegie Observatories) reports: "We obtained the UVOT V-band data from the Swift quick-look webpage and performed aperture photometry on the two epochs discussed in GCN 3516. We find that the afterglow faded by 1.3 mag between the two observations rather than 3.6 mag as reported in GCN 3516." This message may be cited [GCN OPS NOTE(04jun05): Per author's request, the Subject line was corrected from "050406" to "050603".] //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3518 SUBJECT: Konus-Wind observation of GRB 050603 DATE: 05/06/04 15:44:05 GMT FROM: Dmitry Frederiks at Ioffe Institute S. Golenetskii, R.Aptekar, E. Mazets, V. Pal'shin, D. Frederiks, and T. Cline on behalf of the Konus-Wind team report: The long bright multipeak GRB 050603 (Swift-BAT trigger=131560: GCN 3509, 3512) triggered Konus-Wind at T0=23340.767 s UT (06:29:00.767). As observed by Konus-Wind it had a duration of ~6 s, fluence (3.41 ± 0.06)10-5 erg/cm2, peak flux on 16-ms time scale (3.2 ± 0.2)10-5 erg/cm2 s (both in the 20 keV - 3 MeV energy range). A weak decaying tail after the last, brigtest spike of the GRB is seen up to ~11 s after T0 (this tail was seen and repoted by Swift-BAT in GCN 3512). The time-integrated spectrum is well fitted by a GRB (Band) model: the low-energy photon index is alpha = -0.79 ± 0.06, the high energy photon index beta = -2.15 ± 0.09, the break energy E0 = 289 ± 36 keV, and the peak energy Ep = 349 ± 28 keV. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3519 SUBJECT: GRB 050603 - XRT data analysis of the first day DATE: 05/06/05 17:25:30 GMT FROM: Dirk Grupe at PSU/Swift-XRT subject: GRB 050603 - XRT data analysis of the first day D. Grupe, A. Retter, D. Burrows, J. Kennea (PSU), and N Gehrels (GSFC), on behalf of the Swift XRT team report: We analyzed the XRT data of the first day of observation of the GRB 050603 (Retter et al., GCN #3509). The observations started approximately 11 hours after the burst (Racusin et al., GCN #3514). Preliminary analysis of the data obtained so far (31 ks) give the following refined coordinates: Ra-2000: 02h 39m 56.8s Dec-2000: -25d 10' 59.8" The centroiding error is 6". This position is about 7" off the X-ray position given in Racusin et al. (GCN #3514) and 5" off the radio position (Cameron, GCN #3113) and the UVOT position given in Brown et al. (GCN #3116). The source had a flux of 2.2e-12 ergs/s/cm2 11 hours after the burst and is decaying with a decay slope alpha=1.78+/-0.14. The X-ray spectrum can be fitted with a single powerlaw with an X-ray spectral slope beta=0.80+/-0.08. The fit is consistent with Galactic absorption (NH=2e20 1/cm2). This message may be cited //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3520 SUBJECT: GRB 050603: Redshift DATE: 05/06/05 21:52:43 GMT FROM: Edo Berger at Carnegie Obs Edo Berger (Carnegie Observatories) and George Becker (Caltech) report: "We obtained a 45-min spectrum of the afterglow of GRB 050603 (GCNs 3509, 3511) with IMACS on the Magellan/Baade telescope on 2005, June 5.40 UT (2.13 days after the burst). We find a single bright emission line at an observed wavelength of 4645.1A, which we interpret as Lyman-alpha at a redshift of z=2.821. At this redshift the isotropic-equivalent gamma-ray energy is 2.3e54 erg (using a fluence of 3.4e-5 erg/cm^2; GCN 3518). The steep fading observed by the UVOT (GCN 3517) and XRT (GCN 3519) suggests a jet break at t~12 hours after the burst, corresponding to a jet opening angle of about 1.7 deg, and hence a beaming-corrected energy of 1.1e51 erg." //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3522 SUBJECT: GRB 050603: prediction of t_break DATE: 05/06/06 12:07:23 GMT FROM: Gabriele Ghisellini at Obs.Astro. di Brera G. Ghirlanda, G. Ghisellini, C. Firmani, F. Tavecchio (Oss. Astron. di Brera) report: GRB 050603, with a redshift of 2.821 (Berger and Becker, GCN 3520), fluence and spectral parameters as measured by Konus-Wind (Golenetskii et al., GCN 3518), requires an achromatic break at t = 7 +/- 3 days (after trigger) to be consistent with the "Ghirlanda" relation between the collimation corrected energy and Epeak. A plot can be seen at: http://www.merate.mi.astro.it/~ghirla/deep/blink.htm . We urge observations in order to verify this prediction. This message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3549 SUBJECT: CORRECTION: GRB050603 Swift UVOT Afterglow Observations DATE: 05/06/15 01:37:36 GMT FROM: Peter Brown at PSU P. Brown (PSU), A. Retter (PSU), P. Schady (MSSL), P. Boyd (GSFC), S. T. Holland (GSFC/USRA), P. Roming (PSU), C. Gronwall (PSU), N. Cucchiara (PSU), K. Mason (MSSL), N. Gehrels (GSFC), on behalf of the Swift UVOT team: The second V-filter magnitude (V=21.8 at T_start=32997) reported in GCN 3516 for the fading afterglow of GRB050603 is incorrect. An error in the on-board shift-and-add code resulted in an unusually large amount of missing data for this exposure that was not correctly recorded in the exposure information. The real exposure time for the second exposure was adjusted to 101 s to match the actual data contained in the image. The corrected magnitude is 18.7, meaning the afterglow only faded by 0.5 magnitudes between the two observations reported in GCN 3516. In addition, we report the afterglow magnitude in later exposures. An error-weighted powerlaw fit gives a decay index of 1.97 +/- 0.22. The corrected and new afterglow magnitudes from UVOT are as follows: Time (h) Mag Filter Duration (s) 9.5 18.2 +/- 0.1 V 1298 10.9 18.7 +/- 0.4 V 101 12.7 19.5 +/- 0.2 V 1772 14.4 19.3 +/- 0.2 V 2104 15.9 19.0 +/- 0.2 V 1200 17.8 19.7 +/- 0.3 V 1205 20.8 20.1 +/- 0.4 V 1948 36.1 21.1 +/- 0.4 V 10,458 (9 exposures coadded) Time (h) is the midpoint of the exposure given in hours after the burst trigger. The reported errors do not include a +/- 0.09 error in the preliminary inflight zero point calibration.