//////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 5220 SUBJECT: GRB 060605: ROTSE-III Detection of Optical Counterpart DATE: 06/06/05 18:25:27 GMT FROM: Eli Rykoff at U of Michigan/ROTSE E.S. Rykoff (U Mich), B. E. Schaefer (Louisiana State), report on behalf of the ROTSE collaboration: ROTSE-IIIa, located at Siding Spring Observatory, Australia, responded to GRB 060605 (Swift trigger 213630). The first image was at 18:16:33.3 UT, 48.7 s after the burst (5.4 s after the GCN notice time). The unfiltered images are calibrated relative to USNO A2.0. We detect a 16.3 magnitude, steady source with coordinates: 21:28:37.3 -06:03:30.6 (J2000) start UT mag mlim(of image) ---------------------------------- 18:17:18.0 16.3 16.5 This source is not visible in DSS (second epoch), 2MASS or the MPChecker database. A jpeg image is available at http://www.rotse.net/images/gsb213630_3a001-010_key.jpg Continuing observations are in progress. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 5221 SUBJECT: GRB 060605: Swift detection of a burst with optical counterpart DATE: 06/06/05 18:40:14 GMT FROM: Jamie A. Kennea at PSU/Swift-XRT M. J. Page (UCL-MSSL), A. J. Blustin (UCL-MSSL), P. J. Brown (PSU), O. Godet (U Leicester), S. T. Holland (GSFC/USRA), J. A. Kennea (PSU), H. A. Krimm (GSFC/USRA), C. Pagani (PSU), A. M. Parsons (GSFC), G. Sato (GSFC/JSPS/USRA) and M. Stamatikos (NASA/ORAU) report on behalf of the Swift Team: At 18:15:44 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 060605 (trigger=213630). Swift slewed immediately to the burst. The BAT on-board calculated location is RA,Dec 322.144, -6.060 {21h 28m 35s, -06d 03' 36"} (J2000) with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a FRED-like structure with a duration of about 20 sec. The peak count rate was ~2000 counts/sec (15-350 keV), at ~0 sec after the trigger. The XRT began taking data at 18:17:17 UT, 93 seconds after the BAT trigger. The XRT on-board centroid algorithm did not find a source in the image, however analysis of downlinked PC mode data finds a faint, uncatalogued point source at the following location: RA(J2000): 21h 28m 37.2s Dec(J2000): -06d 03m 35.3s, with an estimated error of 4 arcsec radius (90% containment). This position is 39 arcsec from the center of the BAT error circle and is 4.5 arcsec from the UVOT candidate. UVOT took a finding chart exposure of 100 seconds with the White (160-650 nm) filter starting 98 seconds after the BAT trigger. There is a candidate afterglow in the rapidly available 2.7'x2.7' sub-image at (RA,DEC) (J2000) of (322.1555,-6.0587) or (21h28m37.32s,-06o03'31.3") with a 1-sigma error radius of about 0.5 arc sec. This position is 41.3 arc sec. from the centre of the BAT error circle. The estimated magnitude is 17.4 with a 1-sigma error of about 0.5 mag. No correction has been made for the expected extinction corresponding to E(B-V) of 0.05. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 5222 SUBJECT: GRB 060605: ROTSE-III Optical Counterpart DATE: 06/06/05 20:04:25 GMT FROM: Brad Schaefer at LSU B. E. Schaefer (Louisiana State), E.S. Rykoff (U Mich), D.A. Smith (Guilford), R. Quimby (U Texas), report on behalf of the ROTSE collaboration: ROTSE-IIIa, located at Siding Spring Observatory, Australia, found a bright optical transient (Rykoff et al. 2006, GCN 5220) near the center of the Swift BAT position for GRB 060605A (M. J. Page et al. 2006, GCN 5221). The Swift XRT and UVOT later reported a fading counterpart at this same position (Page et al. 2006, GCN 5221). In the first ROTSE image (started 48.7 s after the burst) the source was fainter than 16.5 mag (calibrated against USNO stars in the R-band). The source rapidly brightened to roughly 15.7 mag by 150 seconds, and after a short plateau has since been fading fast. Our light curve shows some apparently significant fluctuations starting ~1400 seconds after the burst. The decline after 1000 seconds roughly follows a power law with index of -0.8. A jpeg image is available at http://www.rotse.net/images/gsb213630_3a011-020_key.jpg The optical transient is indicated by the central yellow circle labelled as object 44, while the blue circles represent stars in the USNO B1.0 catalog. Continuing observations are in progress. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 5223 SUBJECT: GRB060605: Spectral Observations and Redshift DATE: 06/06/05 21:48:49 GMT FROM: Brian Schmidt at RSAA, ANU (MSSSO) B. Peterson and B. Schmidt (ANU) on behalf of a larger collaboration report, "We have obtained imaging and spectra of GRB060605 (GCN 5221) with the ANU 2.3m telescope and confirm the candidate of Rykoff et al. (GCN 5220). The spectrum taken with the Double Beam Spectrograph reveals a strong absorption feature at 5850A with many absorption lines to the blue of this feature. To the red, the spectrum has only a few very weak absoption lines and is otherwise a featureless power law. Associating the absorption feature at ~5850 with Ly-alpha gives a redshift of z=3.8 for the burst." //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 5224 SUBJECT: GRB 060605: RTT150 optical observations DATE: 06/06/06 05:45:23 GMT FROM: Irek Khamitov at TUG I. Khamitov (TUG), A.T.Saygac (Ist.Uni), Z. Aslan (TUG), U. Kiziloglu (METU), E. Gogus (Sabanci Uni.), S.Alis, O.Onal (Ist.Uni) R. Burenin, M. Pavlinsky, R. Sunyaev (IKI) I. Bikmaev, N. Sakhibullin (KSU/AST), report: We observed the field around the position of the optical counterpart (Rykoff et al. GCN 5220, Page et al., GCN5221) of GRB060605 (Swift trigger 213630) with the Russian-Turkish 1.5-m telescope (RTT150, Bakirlitepe, TUBITAK National Observatory, Turkey), starting at June 05, 23:41 UT, i.e. ~5.42 hours after the burst. A series of frames was taken (20*60s exposures in R) with TFOSC. The afterglow is detected clearly in all images. Observations were made under strong wind weather. Using USNO-B1 star (RA=21:28:40.26, DEC=-06:03:44.5, R2MAG=15.37) we estimate the following Rc magnitudes for the OT: t-t0 m_R err 5.62 19.767 0.03 5.83 19.873 0.03 6.17 19.911 0.03 6.37 20.010 0.04 The power-law decay index in R is -1.6+-0.3 between 5.62 and 6.37 hours after the burst. Comparing our decay slope with that derived from earlier ROTSE data (Schaefer et al., GCN 5222) we conclude that there was a break in OT light curve between 1 and 5 hours after the burst. This message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 5225 SUBJECT: GRB 060605: TNG optical observations DATE: 06/06/06 07:59:45 GMT FROM: Daniele Malesani at SISSA-ISAS,Trieste,Italy D. Malesani (SISSA), F. Fiore (INAF/OAR), N. Masetti (INAF/IASF Bo), M. Pedani, G. Mainella (INAF/TNG), report on behalf of a larger collaboration: We observed the afterglow of GRB 060605 (Page et al., GCN 5221; Rykoff & Schaefer, GCN 5220) with the 3.6m TNG telescope, starting at 02:55 UT (8.64 hr after the burst). In a single 3-min exposure the afterglow is well detected with a magnitude R~19.65 after comparison with several USNO stars. A finding chart can be found here (comparison stars used for the photometry are circled): http://www.sissa.it/~malesani/GRB/060605/finder_TNG.jpg This message can be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 5226 SUBJECT: SALT spectroscopy of GRB 060605 DATE: 06/06/06 09:25:56 GMT FROM: Martin Still at S.African Astro Obs M. Still. A. Kniazev, E. Romero-Colmenero, Y. Hashimoto, N. Loaring, P. Vaisanen, D. Buckley, P. Charles, D. O'Donoghue (SAAO), K. Nordsieck, E. Burgh (Wisconsin), D. Reichart (N. Carolina) The 10-m Southern African Large Telescope (SALT), currently undergoing Performance- Verification, observed the afterglow of GRB 060605 (Page et al.; GCN 5221) on Jun 6, 2006 at 00:53 UT with the Robert Stobie Spectrograph. The Lyman limit was detected at 4300 Angstroms. We can therefore verify that the absorption feature reported by Schmidt (GCN 5223) is indeed Ly alpha, which we centroid at 5720 Angstroms. This line and the Ly limit indicate that the source redshift is z = 3.7. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 5227 SUBJECT: GRB 060605: Swift-XRT Team refined analysis DATE: 06/06/06 11:30:05 GMT FROM: Olivier Godet at U.of Leicester O. Godet, K.L. Page, E. Rol, A.P. Beardmore (U. Leicester), M.J. Page (UCL-MSSL) report on behalf of the Swift-XRT team: We have analysed the first 5 orbits of X-ray data obtained for GRB 060605 (BAT trigger 213630). Using 10.4 ks of Photon Counting (PC) mode data, we find a refined position of: RA(J2000) = 21h 28m 37.16s Dec(J2000) = -06d 03' 33.8" with an uncertainty of 3.6 arcsec (90% containment). This is 0.7 and 2.7 arcsec from the on-board XRT and UVOT positions respectively and 38.8 arcsec from the on-board BAT position given in GCN 5221 by Page et al. The source was relatively faint in the XRT. The light-curve shows the common steep-to-flat-to-steep transition: i) for the first steep segment, alpha_1 = 2.34 +/-0.55 followed by a break at t1 = 171 +/-26s after the BAT trigger (T0); for the shallow decay, alpha_2 = 0.38 +0.05/-0.06 followed by another break at t2 = T0+5508 + 2029/-904s; iii) alpha_3 = 1.23 +0.73/-0.23. The first orbit of the WT data (from T0+99s to T0+124s) is well fitted by a single power-law with Gamma = 1.6 +0.42/-0.39, with no strong evidence for excess NH above the Galactic value of 5.1e20 cm^-2. The spectrum of the PC data from T0+126s to T0+2.4e4s is well fitted by a single power-law with Gamma = 1.97 +/-0.06, again with no strong evidence for excess NH above the Galactic value of 5.1e20 cm^-2. The unabsorbed flux in the 0.3-10 keV energy band is 7.5 +0.7/-0.6 e-12 erg cm^-2 s^-1. No significant spectral evolution is seen before and after the second break at t2. We note that Khamitov et al. (GCN 5224) claimed for a break in optical between T0+1 and T0+5 hours, which could be consistent with the second break at t2 seen in the XRT light-curve. Assuming the decay continues to follow the temporal slope alpha_3, the predicted count rate at T0+24 hours is 0.010 count s^-1, corresponding to an observed (unabsorbed) flux of 4.46e-13 (5.13e-12) erg cm^-2 s^-1. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 5228 SUBJECT: GRB060605: Swift/UVOT detections DATE: 06/06/06 11:50:44 GMT FROM: Alexander Blustin at MSSL-UCL A. J. Blustin (UCL-MSSL) and M. J. Page (UCL-MSSL) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB060605 at 18:17:21 on 2006-06-05, 97 s after the BAT trigger (Page et al., GCN 5221). An optical afterglow was detected at (RA,DEC) (J2000) of (21h28m37.32s,-06o03'31.3") with a 1-sigma error radius of about 0.5 arcsec, in the V, B and White filters, which is consistent with the redshifts of 3.8 (Peterson et al., GCN 5223) or 3.7 (Still et al., GCN 5226) already reported for this GRB. Magnitudes and three-sigma upper limits are as follows: Filter T_range(s) Exp(s) Mag/3sig_UL V 202-595 386 16.53 +/- 0.04 V 10172-10471 291 19.0 +/- 0.2 B 4388-4588 190 20.0 +/- 0.2 B 23023-23322 287 21 +/- 1 U 4184-23017 2140 21.1 (3sig_UL) UVW1 3979-22104 2030 20.2 (3sig_UL) UVM2 3774-11377 1267 20.7 (3sig_UL) UVW2 4798-6381 338 19.9 (3sig_UL) White 97-197 98 17.64 +/- 0.06 White 17477-17776 291 20.5 +/- 0.3 These values are not corrected for the estimated Galactic extinction of E(B-V) = 0.049. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 5230 SUBJECT: GRB 060605: Xinglong TNT optical observations DATE: 06/06/06 15:34:16 GMT FROM: W.K. Zheng at NAOC M.Zhai, Y.L. Qiu, J.Y. Wei, J.Y. Hu, J.S. Deng and W.K. Zheng, on behalf of EAFON report: We have imaged the field of GRB 060605 with the TNT 0.8m telescope at Xinglong Observatory.The first image was taken at 18:19:35 UT, 231s after the trigger.the optical counterpart (Rykoff et al. GCN 5220, Page et al., GCN5221) were all detected in our clear and R band images. The whole observation last about 1.3 hours.Preliminary analyses reveal a peak Mag at bout 430s with n~15.32 derived from USNO-B1.0 R catalog. Further analysis is under progress. This message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 5231 SUBJECT: GRB 060605 BAT refined analysis DATE: 06/06/06 17:12:46 GMT FROM: Jay R. Cummings at NASA/GSFC/Swift G. Sato (GSFC/JSPS/USRA), L. Barbier (GSFC), S. Barthelmy (GSFC), J. Cummings (GSFC/UMD), E. Fenimore (LANL), N. Gehrels (GSFC), D. Hullinger (BYU-Idaho), H. Krimm (GSFC/USRA), M. Koss (GSFC/UMD), C. Markwardt (GSFC/UMD), D. Palmer (LANL), A. Parsons (GSFC), T. Sakamoto (GSFC/ORAU), M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC), on behalf of the Swift-BAT team: Using the data set from T-119.9 to T+182.2 sec from the recent telemetry downlink, we report further analysis of BAT GRB 060605 (trigger #213630) (Page, et al., GCN #5221). The BAT ground-calculated position is (RA,Dec) = 322.157, -6.046 deg {21h 28m 37.6s, -6d 2' 44.7"} (J2000) +- 1.5 arcmin, (radius, sys+stat, 90% containment). The partial coding was 87%. The light curve shows two overlapping FRED peaks of similar size. T90 (15-350 keV) is 15 +- 2 sec (estimated error including systematics). The time-averaged spectrum from T-1.5 to T+15.0 is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.34 +- 0.15. The fluence in the 15-150 keV band is 4.6 +- 0.4 x 10^-07 erg/cm2. The 1-sec peak photon flux measured from T+1.67 sec in the 15-150 keV band is 0.5 +- 0.1 ph/cm2/sec. All the quoted errors are at the 90% confidence level. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 5235 SUBJECT: GRB 060605: RTT150 optical observations DATE: 06/06/07 05:50:54 GMT FROM: Irek Khamitov at TUG I. Khamitov (TUG), A.T. Saygac (Ist.Uni), Z. Aslan (TUG), U. Kiziloglu (METU), E. Gogus (Sabanci Uni.), S.Alis, O.Onal (Ist.Uni) R. Burenin, M. Pavlinsky, R. Sunyaev (IKI) I. Bikmaev, N. Sakhibullin (KSU/AST), report: We observed the field around the position of the optical counterpart (Rykoff et al. GCN5220, Page et al., GCN5221) of GRB060605 (Swift trigger 213630) with the Russian-Turkish 1.5-m telescope (RTT150, Bakirlitepe, TUBITAK National Observatory, Turkey), at the beginning of June 07, about 31.1 hours after the burst. A series of frames was taken in R band with TFOSC. The afterglow is detected on combined image. http://www.tug.tubitak.gov.tr/~irekk/grb/grb060605/GRB060605_0607_RTT150.JPG Using USNO-B1 star (RA=21:28:40.26, DEC=-06:03:44.5, R2MAG=15.37) we estimate the following R magnitude for the OT: t-t0 m_R err 31.1 23.0 0.2 Using all data (Khamitov et al., GCN5224) we estimate the power-law decay index in R as -1.7+-0.02, which did not changed since ~5.6 hours after the burst. Our R lightcurve can be found at: http://www.tug.tubitak.gov.tr/~irekk/grb/grb060605/GRB060605_lc0607.jpg This message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 5260 SUBJECT: GRB 060605, optical observations DATE: 06/06/15 15:55:39 GMT FROM: Peter Garnavich at U of Notre Dame Agata Karska and Peter Garnavich (Notre Dame) We observed the position of GRB 060605 (Rykoff et al., GCN 5220) with the Vatican Advanced Technology Telescope (VATT) and 2KCCD camera on 2006 June 6.44 UT (16.3 hours after the burst). Three R-band images, each with an exposure time of 300s, were combined and a source detected at the Swift/UVOT position (Page et al., GCN 5221). Using an average of five USNO-B1.0 stars (magR1) to set the zero-point we estimate the brightness of the afterglow at R=21.5 +/- 0.2 mag. We note that the USNO-B1.0 magR2 values for the star used by Khamitov et al. (GCN 5224, 5235) and for other stars in the field provide an inconsistent zero-point with variations of 0.6 mag when compared to the instrumental magnitudes of our R-band image. However, the magR1 estimates for the five star are consistent to 0.1 mag. Assuming the same calibration as Khamitov et al. (shifting our GRB magnitude fainter by 0.7 mag) provides a power law decay index of 2.1 between 6 and 16 hours after the burst. Adding the Khamitov et al. observation 31 hours after the burst significantly decreases the decay slope and may indicate contamination from the host galaxy. This burst was observed by the Spitzer Space Telescope and any additional photometry would be useful in interpreting the infrared data. This message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 5263 SUBJECT: GRB060605: optical observation DATE: 06/06/15 18:32:17 GMT FROM: Alexei Pozanenko at IKI, Moscow D. Sharapov (MAO and NOT, La Palma), T. Augusteijn (NOT, La Palma), A.Pozanenko (IKI) on behalf of larger GRB follow up collaboration report: We observed the afterglow of GRB060605 (Page et al., GCN 5221; Rykoff & Schaefer, GCN 5220) in Nordic Optical Telescope with ALFOSC between (UT) June 06 04:27 and 04:50. Based on several field stars of USNO B1.0 we estimate the afterglow brightness in a combined image (5x180 s) as R=20.32 +/- 0.013 at mid time T0+10.38h. This message can be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 5310 SUBJECT: GRB 060605: SkyNet Optical Limits DATE: 06/07/14 01:48:56 GMT FROM: Melissa Nysewander at UNC,Chapel Hill A. Smith, S. Parris, J. Kirschbrown, J. Harvey, G. Spear, T. Graves, M. Nysewander, D. Reichart, K. Ivarsen, A. Foster, A. LaCluyze, and J.A. Crain report: SkyNet observed the localization of GRB 060605 (Page et al., GCN 5221) beginning at 06:55:02 UT on 06/06/2006, 12.7 hours after the initial trigger with the 14.5" TTT Telescope and the 14" GORT (GLAST Optical Robotic) Telescope, located at Hume Observatory, California: Filter Start (UT) Stop (UT) Exposure Total (hr) Telescope V 08:20:36 09:43:56 160s x 26 1.2 TTT Red* 06:55:02 10:10:50 160s x 32 1.4 TTT V 09:47:32 11:32:12 160s x 38 1.7 GORT B 08:47:59 09:44:22 160s x 21 0.9 GORT Observations were taken under poor conditions. We do not detect the afterglow (Rykoff et al., GCN 5220) down to 3-sigma limiting magnitudes of V > 20.0 at a mean time of 14.8 hours, Red > 18.5 at 13.4 hours with TTT, and V > 19.1, B > 16.7 at 16.4 and 15.0 hours respectively with GORT. *Red well approximates the R-band. [GCN OPS NOTE(14jul06): Several authors were added.] //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 5486 SUBJECT: GRB 060605: VLA Observation DATE: 06/08/29 16:29:16 GMT FROM: Poonam Chandra at U Virginia/NRAO P. Chandra (UVA/NRAO) and D. A. Frail (NRAO) report on behalf of the Caltech-NRAO-Carnegie GRB Collaboration: "We observed the field centered on the BAT position of the Swift burst GRB 060605 (GCN#5221) at a redshift of Z=3.8 (GCN#5223) using the VLA at a frequency of 8.46 GHz and starting at 10.24 UT on Aug 20, about 106 days after the burst. There is no detection of the GRB with 2-sigma upper limit of 94 microJy. The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc." //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 5489 SUBJECT: GRB 060605, observations using an Integral Field Unit DATE: 06/08/30 10:49:11 GMT FROM: Sylvio Klose at TLS Tautenburg P. Ferrero, S. Klose, D. A. Kann, Thueringer Landessternwarte Tautenburg, P. Boehm, M. M. Roth, AIP Potsdam, S. F. Sanchez, Centro Astronomico Hispano Aleman de Calar Alto, J. Greiner, S. Savaglio, MPE Garching, and N. Masetti, INAF-IASF, Bologna, report: We imaged in 3D the error circle of GRB 060605 using the Integral Field Unit PMAS/PPak (Roth et al. 2005, PASP 117, 620; Kelz et al. 2006, PASP 118, 129) mounted at the Calar Alto 3.5-m telescope. Observations started about 7.5 hours after the burst and were performed with the V300 grating, covering the wavelength region from about 300 to 710 nm. In the spectrum of the optical transient we detect a deep Lyman alpha trough, which was also noted by Peterson & Schmidt 2006 (GCN 5223) and Still et al. 2006 (GCN 5226). We identify absorption lines from Si II, C II and O I at a redshift of z=3.711, which we consider as the redshift of the GRB host galaxy. This message may be quoted. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 5822 SUBJECT: GRB 060605: NIR Observations DATE: 06/11/15 11:13:12 GMT FROM: Adria C. Updike at Clemson U A. C. Updike, B. C. Donehew, and D. H. Hartmann (Clemson University) report on behalf of the Clemson GRB Follow-Up Team: Using the Kitt Peak 2.1m telescope and FLAMINGOS NIR imaging and spectroscopy instrument, we imaged the field of GRB 060605. Under fair conditions, we integrated for two hours in the J band. At the location of the optical afterglow (GCN 5222), we do not detect the host galaxy to a limiting magnitude of 17.4. The Clemson University GRB Response Site can be found at: http://people.clemson.edu/~kgarime/burst/index.php This message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6166 SUBJECT: GRB 060605 new redshift DATE: 07/03/02 10:53:40 GMT FROM: Patrizia Ferrero at TLS Tautenburg S. Savaglio, MPE Garching,  E. Palazzi, INAF-IASF, Bologna, P. Ferrero & S. Klose, TLS Tautenburg, report: We have re-analyzed the spectrum of GRB 060605 afterglow taken with   the Integral Field Unit PMAS/PPak (Ferrero et al. 2006, GCN 5489). We   found a new strong SiIV absorption system with Ly-alpha, at redshift   z=3.78. This redshift is higher than the previous claimed redshift of   the GRB, z=3.711 (Ferrero et al. 2006, GCN 5489), which also show   SiIV absorption. These two SiIV  absorptions are separated by about   4000 km/s, and are similar to the double CIV absorption detected in   the afterglow of GRB 021004 (separation 2400 km/s; Savaglio et al.   2002, GCN 1633; Fiore et al. 2005, 624, 853) and GRB 030226   (separation 2400 km/s; Klose et al. 2004, AJ 128, 1942). A redshift z=3.8 for GRB 060605 was previously suggested by Peterson   et al. (GCN 5223). This message may be quoted.