GRB 060605
GCN Circular 5220
Subject
GRB 060605: ROTSE-III Detection of Optical Counterpart
Date
2006-06-05T18:25:27Z (19 years ago)
From
Eli Rykoff at U of Michigan/ROTSE <erykoff@umich.edu>
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.
GCN Circular 5221
Subject
GRB 060605: Swift detection of a burst with optical counterpart
Date
2006-06-05T18:40:14Z (19 years ago)
From
Jamie A. Kennea at PSU/Swift-XRT <kennea@astro.psu.edu>
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.
GCN Circular 5222
Subject
GRB 060605: ROTSE-III Optical Counterpart
Date
2006-06-05T20:04:25Z (19 years ago)
From
Brad Schaefer at LSU <schaefer@grb.phys.lsu.edu>
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.
GCN Circular 5223
Subject
GRB060605: Spectral Observations and Redshift
Date
2006-06-05T21:48:49Z (19 years ago)
From
Brian Schmidt at RSAA, ANU (MSSSO) <brian@mso.anu.edu.au>
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."
GCN Circular 5224
Subject
GRB 060605: RTT150 optical observations
Date
2006-06-06T05:45:23Z (19 years ago)
From
Irek Khamitov at TUG <irekk@tug.tug.tubitak.gov.tr>
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.
GCN Circular 5225
Subject
GRB 060605: TNG optical observations
Date
2006-06-06T07:59:45Z (19 years ago)
From
Daniele Malesani at SISSA-ISAS,Trieste,Italy <malesani@sissa.it>
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.
GCN Circular 5226
Subject
SALT spectroscopy of GRB 060605
Date
2006-06-06T09:25:56Z (19 years ago)
From
Martin Still at S.African Astro Obs <still@saao.ac.za>
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.
GCN Circular 5227
Subject
GRB 060605: Swift-XRT Team refined analysis
Date
2006-06-06T11:30:05Z (19 years ago)
From
Olivier Godet at U.of Leicester <og19@star.le.ac.uk>
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.
GCN Circular 5228
Subject
GRB060605: Swift/UVOT detections
Date
2006-06-06T11:50:44Z (19 years ago)
From
Alexander Blustin at MSSL-UCL <ajb@mssl.ucl.ac.uk>
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.
GCN Circular 5230
Subject
GRB 060605: Xinglong TNT optical observations
Date
2006-06-06T15:34:16Z (19 years ago)
From
W.K. Zheng at NAOC <zwk@bao.ac.cn>
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.
GCN Circular 5231
Subject
GRB 060605 BAT refined analysis
Date
2006-06-06T17:12:46Z (19 years ago)
From
Jay R. Cummings at NASA/GSFC/Swift <jayc@milkyway.gsfc.nasa.gov>
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.
GCN Circular 5235
Subject
GRB 060605: RTT150 optical observations
Date
2006-06-07T05:50:54Z (19 years ago)
From
Irek Khamitov at TUG <irekk@tug.tug.tubitak.gov.tr>
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.
GCN Circular 5260
Subject
GRB 060605, optical observations
Date
2006-06-15T15:55:39Z (19 years ago)
From
Peter Garnavich at U of Notre Dame <pgarnavi@nd.edu>
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.
GCN Circular 5263
Subject
GRB060605: optical observation
Date
2006-06-15T18:32:17Z (19 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
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.
GCN Circular 5310
Subject
GRB 060605: SkyNet Optical Limits
Date
2006-07-14T01:48:56Z (19 years ago)
From
Melissa Nysewander at UNC,Chapel Hill <mnysewan@physics.unc.edu>
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.]
GCN Circular 5486
Subject
GRB 060605: VLA Observation
Date
2006-08-29T16:29:16Z (19 years ago)
From
Poonam Chandra at U Virginia/NRAO <pc8s@virginia.edu>
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."
GCN Circular 5489
Subject
GRB 060605, observations using an Integral Field Unit
Date
2006-08-30T10:49:11Z (19 years ago)
From
Sylvio Klose at TLS Tautenburg <klose@tls-tautenburg.de>
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.
GCN Circular 5822
Subject
GRB 060605: NIR Observations
Date
2006-11-15T11:13:12Z (19 years ago)
From
Adria C. Updike at Clemson U <aupdike@clemson.edu>
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.
GCN Circular 6166
Subject
GRB 060605 new redshift
Date
2007-03-02T10:53:40Z (18 years ago)
From
Patrizia Ferrero at TLS Tautenburg <ferrero@tls-tautenburg.de>
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.