//////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 5076 SUBJECT: GRB 060505: Swift-BAT detection of a weak burst DATE: 06/05/05 20:35:05 GMT FROM: Jay R. Cummings at NASA/GSFC/Swift D. Palmer, J. Cummings, M. Stamatikos, C. Markwardt, T. Sakamoto At 06:36:01 UT Swift-BAT triggered on GRB 060505 (Trigger #208654). The onboard imaging detected a 6.4 sigma excess. This is below our (6.5 sigma) threshold for ground notification and automatic slew. Subsequent ground analysis imaged a different selection of the data and found a convincing 8.5 sigma excess at (RA, Dec) = 331.765, -27.819 {22h 07m 04s, -27d 49' 09s} (J2000) The light curve shows a weak burst, ~1500 cts/sec (15-350 keV) 1 sec after the trigger. T90 is ~4 seconds. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 5078 SUBJECT: GRB 060505: Swift XRT afterglow canditate position DATE: 06/05/06 03:28:24 GMT FROM: Milvia Capalbi at ISAC/ASDC M.L. Conciatore, M. Capalbi, L. Vetere (ASDC), D. Palmer (LANL), D. Burrows (PSU) report on behalf of the Swift/XRT team: The Swift XRT began observing GRB 060505 field (trigger #208654, Palmer et al., GCN 5076) at 20:58:25 UT, 14.37 h after the BAT trigger. >From the analysis of the first 4 ks data set we find a faint source at the following coordinates: RA(J2000) = 22h 07m 03.2s Dec(J2000) = -27d 48' 57" with an estimated uncertainty of 5 arcseconds (90% containment). This position lies 13.9 arcseconds from the center of the BAT error circle reported in GCN 5076. This source is 6.7 arcsec from the USNO star 0621-1164653 and 4.1 arcsec from the 2df galaxy S173Z112. Due to the small number of counts, we are unable to determine whether the source is decaying at this time. Observations are continuing and further analysis regarding the fading nature of this source will be issued as the data becomes available. This circular is an official product of the Swift XRT Team. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 5081 SUBJECT: GRB 060505: Swift XRT Team Refined Analysis DATE: 06/05/06 16:54:21 GMT FROM: Maria Laura Conciatore at ASDC M.L. Conciatore, M. Capalbi, L. Vetere (ASDC), L.A. Antonelli (INAF/OAR), D. Palmer (LANL), D. Burrows (PSU) report on behalf of the Swift/XRT team: We analysed the first 8 ks XRT data from GRB 060505. We found two detections whithin the BAT error circle (GCN 5076). The first source already reported in GCN 5078 shows a constant flux of (1.1 +/- 0.1)e-2 counts/s and it is unlikely to be associated with the afterglow of GRB 060505. We also note that the 2df galaxy S173Z112 lays within the XRT error circle (GCN 5078). A very faint second source is located at: RA(J2000) = 22h 07m 4.5s, Dec(J2000) =-27d 49m 57.8s with an uncertainty of 4.7 arcsec (90% containment). This position lies 63.2 arcseconds from the center of the BAT error circle reported in GCN 5076. Due to the small number of counts (15 counts) we are unable to determine whether the source is the possible afterglow candidate of GRB 060505. We note that the positions of both sources are also consistent with a previously known ROSAT source (1WGA J2207.0-2749) error box (50 arcsec). This Circular is an official product of the Swift XRT Team. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 5082 SUBJECT: GRB060505: Swift/UVOT Observations DATE: 06/05/06 17:17:46 GMT FROM: Peter Brown at PSU P J. Brown (Penn State) & D. Palmer (LANL) on behalf of the Swift/UVOT team. The Swift/UVOT began observing the field of GRB060505 (BAT Trigger=208654, Palmer et. al, GCN 5076) at 2006-05-05 20:58:30 UT, 14.37 hours after the BAT trigger. The galaxy at the position of the first XRT source (Conciatore et al GCN 5078) is detected in all 6 filters but does not show significant variation, consistent with Conciatore et al (GCN 5081). No source is detected at the position of the second XRT source (Conciatore et al GCN 5081) in coadded images with any of the filters. The following 5-sigma magnitude upper limits are not corrected for Galactic extinction. Filter T_range(h) T_exp(s) 5sigmaUpperLimit(mag) V 14.85-19.73 835 19.1 B 14.56-19.44 835 20.2 U 14.49-19.38 835 19.9 UVW1 14.37-19.32 1666 19.8 UVM2 14.92-19.85 1987 20.1 UVW2 14.62-19.67 3388 21.0 Where T_range is time post-trigger in hours, and T_exp is the exposure time of the summed image in seconds. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 5089 SUBJECT: GRB 060505: PROMPT Observations DATE: 06/05/08 00:12:19 GMT FROM: Josh Haislip at U.North Carolina J. Haislip, M. Nysewander, D. Reichart, A. LaCluyze, J. A. Crain, K. Ivarsen, A. Foster, C. MacLeod, J. Kirschbrown, A. Trotter, and J. Carpenter report on behalf of the UNC team of the FUN GRB Collaboration: Skynet observed the localization of GRB 060505 (Palmer et al., GCN 5076) with three of the 16-inch PROMPT telescopes at CTIO beginning 23.2 hours after the burst in Ug'r'i'z'. Two of these telescopes reobserved the field in i'z' beginning 47.2 hours after the burst. No new source is found to z' > 20.6 mag (3 sigma) at 25.5 hours after the burst. PROMPT is currently being built and commissioned. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 5114 SUBJECT: GRB 060505: X-ray afterglow DATE: 06/05/11 15:35:56 GMT FROM: Maria Laura Conciatore at ASDC M.L. Conciatore, M. Capalbi, L. Vetere (ASDC), D. Palmer (LANL), D. Burrows (PSU) report on behalf of the Swift/XRT team: The Swift X-Ray Telescope observed the field of GRB 060505 (GCN 5076) for a second time on 2006-05-10 from 00:43:58 UT for a total exposure of 11.7 ks. The source identified in the first observation (GCN 5078) located at: RA(J2000) = 22h 07m 03.2s Dec(J2000) = -27d 48' 57 has faded from (1.1 +/- 0.1)e-2 counts/s to (8.6 +/- 4.0)e-4 cts/s. The other source reported in GCN 5081, located at: RA(J2000) = 22h 07m 4.5s, Dec(J2000) =-27d 49m 57.8s shows a constant behavior of the light curve, with a count rate of about 2e-2 cts/s. We conclude that the first source is the likely X-ray afterglow of GRB 060505. This Circular is an official product of the Swift XRT Team. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 5115 SUBJECT: GRB 060505: X-ray afterglow - Correction - DATE: 06/05/11 16:41:45 GMT FROM: Maria Laura Conciatore at ASDC M.L. Conciatore (ASDC) report on behalf of the Swift/XRT team: In GCN 5114, we incorrectly reported that count rate of the second source (the constant one) was 2.e-2 cts/s. The correct value is 2.e-3 cts/s. Please, find below the corrected GCN text. ======================================================================== M.L. Conciatore, M. Capalbi, L. Vetere (ASDC), D. Palmer (LANL), D. Burrows (PSU) report on behalf of the Swift/XRT team: The Swift X-Ray Telescope observed the field of GRB 060505 (GCN 5076) for a second time on 2006-05-10 from 00:43:58 UT for a total exposure of 11.7 ks. The source identified in the first observation (GCN 5078) located at: RA(J2000) = 22h 07m 03.2s Dec(J2000) = -27d 48' 57 has faded from (1.1 +/- 0.1)e-2 counts/s to (8.6 +/- 4.0)e-4 cts/s. The other source reported in GCN 5081, located at: RA(J2000) = 22h 07m 4.5s, Dec(J2000) =-27d 49m 57.8s shows a constant behavior of the light curve, with a count rate ofabout 2e-3 cts/s. We conclude that the first source is the likely X-ray afterglow of GRB 060505. This Circular is an official product of the Swift XRT Team. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 5123 SUBJECT: GRB 060505 - OT candidate + galaxy spectrum DATE: 06/05/13 02:18:58 GMT FROM: Eran Ofek at Tel Aviv U. E. O. Ofek, S. B. Cenko, A. Gal-Yam (Caltech), B. Peterson, B. P. Schmidt, (ANU), D. B. Fox (Penn State), and P. A. Price (IfA, Hawaii) report on behalf of a larger collaboration: We have imaged the region of the 4s-duration GRB060505 (GCNs 5076; 5078; 5114; 5115) with the GMOS instrument on the Gemini South Telescope, in g' and r'-bands, on 2006 May 6.4 and on 2006 May 12.3. Inspection of single g' and r'-band images from each night reveals the presence of a variable source 4."3 from the z=0.089 galaxy 2dFGRS S173Z112 (7kpc in projection). The afterglow coordinates are: 22:07:03.44 -27:48:51.9 (J2000.0) relative to the USNO-A2.0 catalog. The OT is found 6" from the nominal XRT coordinates (which have 4."7 uncertainty, 90% confidence). On 2006 May 6.40, the g'-band magnitude of the proposed afterglow was g~21.5, and on 2006 May 12.31 it was g'~22 (Compared to USNO-A2.0). We further inspected the publicly available 2dF spectra of the z=0.089 galaxy 2dFGRS S173Z112, found within the XRT error circle of GRB 060505 (GCN 5078). The spectra shows prominent emission lines of Halpha, Hbeta, OI, OII, OIII and SII. In absorption we detect the G-band and the CaII H line (but not the K line). The spectrum suggests this is a late type galaxy. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 5142 SUBJECT: GRB 060505 BAT refined analysis DATE: 06/05/15 19:54:31 GMT FROM: Jay R. Cummings at NASA/GSFC/Swift D. Hullinger (BYU-Idaho), L. Barbier (GSFC), S. Barthelmy (GSFC), J. Cummings (GSFC/ORAU), E. Fenimore (LANL), N. Gehrels (GSFC), H. Krimm (GSFC/USRA), M. Koss (GSFC/UMD), C. Markwardt (GSFC/UMD), D. Palmer (LANL), A. Parsons (GSFC), T. Sakamoto (GSFC/ORAU), G. Sato (GSFC/JSPS/USRA), M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC), on behalf of the Swift-BAT team: Using the data set from T-2 to T+8 sec, we report further analysis of GRB 060505 (Palmer et al. GCN 5076). The refined ground-analysis position is RA, Dec 331.776d, -27.825d (22h 07m 06.3s, -27d 49' 31") +- 2.1 arcmin (J2000, estimated uncertainty, 90% containment). This position is 0.6 arcmin from the XRT refined position reported by Conciatore et al. in GCN 5081. The partial coding was 11%. As noted earlier, this was a ground-discovered burst that did not trigger the BAT instrument. Thus we have only a limited set of full-resolution data. The mask-weighted light curve shows a single rounded peak. T90 is 4 +- 1 sec (15-350 keV, estimated error including systematics). The BAT counting rates give no indication of extended emission. However, Swift was approaching the SAA and BAT entered SAA mode with even more limited data collection at T+60, so constraints on emission are poor. The time-averaged spectrum is well fit by a simple powerlaw with index 1.3 +- 0.3. The energy fluence in the 15-150 keV band is 6.2 +- 1.1 x 10^-7 ergs/cm2. The 1-second peak flux, also in the 15-150 keV band, from T+2 sec is 1.9 +- 0.3 ph/cm2/s. All the quoted errors are at the 90% confidence level. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 5161 SUBJECT: GRB060505: VLT observations of the optical afterglow DATE: 06/05/26 14:27:24 GMT FROM: Christina Thoene at Niels Bohr Institute,DARK Cosmo Ctr Christina C. Thoene, Johan P.U. Fynbo, Jesper Sollerman, Brian L. Jensen, Jens Hjorth (Dark Cosmology Centre), Pall Jakobsson (Univ. of Hertfortshire), Sylvio Klose (TLS Tautenburg) report on behalf of a larger collaboration: We observed the OT position of GRB060505 (GCN 5123), with FORS2/VLT on May 23.28. Comparison with our FORS1/VLT images from May 5.41 shows that the source has faded from R=21.3 on May 5.41 to R>23 on May 23.28. At the position of the OT, we detect a bright, star-forming region in the spiral arm of the possible host galaxy 2dFGRS S173Z112 with redshift z=0.089 (GCN 5123). Spectroscopy with VLT/FORS2 confirms that this region is part of the host galaxy. Therefore, it is possible that the source reported in GCN 5123 for images taken on May 12th, might actually be the underlying star-forming region. The observations put a strong limit on the presence of an underlying SN similar to SN 1998bw at redshift 0.089, which we would expect to have a magnitude of R=18.4 at the time of our 2nd observation. Therefore, either there is no associated SN, the SN is about 4 magnitudes fainter than SN 1998bw, it is strongly extinguished, or GRB060505 is not at z=0.089. The strengths of the Balmer lines and the fact that the host galaxy is seen close to face on argue against strong dust extinction. We thank the Paranal staff, in particular Claudio Melo and Rachel Gilmour, for excellent support.