GRB 060204B
GCN Circular 4829
Subject
GRB 060204B: GETS early limit
Date
2006-02-25T07:19:08Z (20 years ago)
From
Kenzo Kinugasa at Gunma Astro. Obs/Japan <kinugasa@astron.pref.gunma.jp>
K. Kinugasa (Gunma Astronomical Observatory) and K. Torii (Osaka U.) report:
The error region of GRB 060204B (Falcone et al. GCN 4655) was imaged
by the robotic 0.25m GETS telescope in the Gunma Astronomical Observatory.
Unfiltered imaging started at 14:36:23 UT (119 s after the BAT trigger)
and 30 s integration was repeated.
We did not detect the optical afterglow (Guidorzi et al. GCN 4661; Moon
& Cenko GCN 4667) and the following 3-sigma upper limits are derived relative
to USNO-A2.0 R mag.
------------------------------------------
StartUT EndUT Limit Nframes
------------------------------------------
14:36:23 14:36:53 >16.9 1
14:36:23 14:50:00 >18.4 20
------------------------------------------
GCN Circular 4704
Subject
GRB 060204b: pseudo-z from spectral parameters of the prompt emission
Date
2006-02-07T14:21:22Z (20 years ago)
From
Jean-Luc Atteia at Lab d Astrophys.,OMP,Toulouse <atteia@ast.obs-mip.fr>
A. Pelangeon & J-L. Atteia (LATT-OMP) report:
We have used the spectral parameters for the most intense part of GRB
060204B (from T0-4.46 sec. to T0+10.54 sec.) kindly provided by T. Sakamoto
(GSFC, private communication) to compute the spectral pseudo-redshift of
this burst detected by SWIFT-BAT (Falcone et al., GCN 4655; Markwardt et
al., GCN 4671).
We find a pseudo-redshift pz= 3.1 � 1.1
This is consistent with the observations of the afterglow by Fynbo et al.
(GCN 4677) who imposes a conservative maximum redshift of z ~< 4.
GCN Circular 4677
Subject
GRB 060204B: BVRi-band detections of optical afterglow
Date
2006-02-05T18:12:58Z (20 years ago)
From
Javier Gorosabel at IAA-CSIC <jgu@laeff.inta.es>
J.P.U. Fynbo, J. Gorosabel(*), B.L. Jensen (DARK Cosmology Centre),
Jyri Naeraenen (Helsinki Observatory) report on behalf of a larger
collaboration:
"We have acquired BVRi-band images (3x300s in each band) of the Swift
GRB 060204B (Trigger number 180241, GCNs #4655, #4669) optical
afterglow (GCN #4661). The source is clearly detected in VRi, and
barely in B. We derive a rough magnitude of R=22.5 on Feb 5.07 UT
(vs. USNOB1). Considering the R=20.4 mag value on Feb. 4.64 UT (as
reported in GCN #4661) we estimate a slow-fading decay index alpha
~-0.8. Our B-band detection imposes a conservative maximum redshift
of z ~< 4.
A finding chart of the R-band afterglow can be found at:
http://www.dsri.dk/~jgu/grb060204B/FCs/grb060204B.NOT.R.gif
This message can be cited."
(*) Visitor at DARK cosmology centre. Default affiliation; IAA-CSIC,
Granada.
GCN Circular 4674
Subject
GRB060204B: Swift/UVOT refined analysis
Date
2006-02-05T06:56:16Z (20 years ago)
From
Antonino Cucchiara at PSU <cucchiara@astro.psu.edu>
A.Cucchiara, A Falcone, S. Hunsberger (PSU),F. Marshall (GSFC),
P. Boyd (GSFC-UMBC), N. Gehrels (GSFC), on behalf of
the Swift UVOT team.
The Swift/UVOT began taking data on the field of GRB 060204B at
14:34:24 UT on 2006-02-04, 101 s after the BAT trigger (Falcone et al.,
GCN 4655). We detected an uncatalogued object cosistent with
the xrt position reported by Falcone et al. (GCN 4669)
and Guidorzi et al. (GCN 4661) in our first 200 exposure V image.
We have no afterglow detection in summed images in
any other filter within the refined XRT error circle down to the
following 3-sigma magnitude upper limits.
Filter T_range(s) Exp(s) mag coadd
V 101-301 200 19.43+/- 0.50 N
B 307-703 396 >20.12 Y
U 4086-4890 91 >19.66 Y
UVW1 4062-4746 98 >18.90 Y
UVM2 4020-4722 95 >18.98 Y
UVW2 427-4237 97 >19.11 Y
These magnitudes are uncorrected for Galactic extinction;
E(B-V) = 0.018.
This message can be cited
GCN Circular 4671
Subject
GRB 060204B: Swift-BAT refined analysis
Date
2006-02-05T04:41:50Z (20 years ago)
From
Takanori Sakamoto at NASA/GSFC <takanori@milkyway.gsfc.nasa.gov>
C. Markwardt (GSFC/UMD), L. Barbier (GSFC), S. Barthelmy (GSFC),
J. Cummings (GSFC/ORAU), E. Fenimore (LANL), N. Gehrels (GSFC),
D. Hullinger (UMD), H. Krimm (GSFC/USRA), F. Marshall (GSFC),
D. Palmer (LANL), A. Parsons (GSFC), T. Sakamoto (GSFC/ORAU),
G. Sato (ISAS), T. Takahashi (ISAS), J. Tueller (GSFC),
on behalf of the Swift-BAT team:
Using the data set from T-299.1 to T+303.0 sec from the recent telemetry
downlink, we report further analysis of BAT GRB 060204B
(trigger #180241) (Falcone, et al., GCN 4655). The BAT ground-calculated
position is (RA,Dec) = 211.812, 27.675 deg {14h 7m 14.9s, 27d 40' 29.1"}
(J2000) +- 0.8 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 77%.
The mask-weighted light curve shows a strong peak with a slow rise starting
from T-30 sec to T+5 sec, and a faster decay till T+30 sec. The weak emission
extends to T+120 sec, and there is a small peak at T+120 sec. There is a
possible precursor at T-165 sec with a width of ~20 sec. T90 (15-350 keV)
is (134 +- 5) sec (estimated error including systematics).
The time-averaged spectrum from T-24.4 to T+170.7 is best fit by
a power law with an exponential cutoff. This fit gives a photon index
0.82 +- 0.40, and Epeak of 96.8 +- 41.0 keV (chi squared 38.83 for 56 d.o.f.).
For this model the total fluence in the 15-150 keV band is
(3.0 +- 0.2) x 10^-06 erg/cm2 and the 1-sec peak flux measured from T+5.04 sec
in the 15-150 keV band is (1.3 +- 0.2) ph/cm2/sec. A fit to a simple power law
gives a photon index of 1.46 +- 0.09 (chi squared 47.69 for 57 d.o.f.).
All the quoted errors are at the 90% confidence level.
GCN Circular 4670
Subject
GRB 060204B: ART early limit
Date
2006-02-05T04:09:16Z (20 years ago)
From
Ken ichi Torii at RIKEN <torii@ess.sci.osaka-u.ac.jp>
K. Torii (Osaka U.) reports on behalf of the ART collaboration:
In addition to that reported in GCN 4660, we made further analysis of the
early ART 3b data for GRB 060204B (Falcone et al. GCN 4655).
The position of the optical afterglow (Guidorzi et al. GCN 4661; Moon
& Cenko GCN 4667) was imaged very close to the edge of the ART 3b
field of view, starting at 14:36:45 (141 s after the BAT
trigger). From the preliminary analysis of a stacked frame (60s x 10
in Ic), we derive the following limit for the afterglow.
-----------------------------
StartUT Mag
=============================
14:36:45 >16.0I
=============================
GCN Circular 4669
Subject
GRB060204B: Swift XRT Team Refined Analysis
Date
2006-02-05T03:44:58Z (20 years ago)
From
Abe Falcone at PSU/Swift <afalcone@astro.psu.edu>
A. D. Falcone (PSU), D. N. Burrows (PSU), D. C. Morris (PSU), N. Gehrels
(GSFC) report on behalf of the Swift XRT team:
We have analyzed the initial Swift XRT data from GRB 060204B (Falcone et
al., GCN4655), with a total exposure of 178 s in Windowed Timing mode
and 7790 s in Photon Counting mode.
The refined XRT position is:
RA(J2000) = 14 07 14.8
Dec(J2000) = +27 40 34
This position is 3" from the initial XRT on-board centroiding position
reported in GCN 4655, and it is 2.8" from the optical detection reported
by Guidorzi et. al (GCN 4661). We estimate an uncertainty of 4
arcseconds radius (90% containment).
The early light curve is dominated by flaring with rates reaching
approximately 200 c/s. Following the initial flaring, the light curve
is clearly fading, but the rate is difficult to estimate due to the
flaring and the limited data available at this time. A preliminary
estimate of the power law decay index is approximately 0.6 +/- 0.4,
immediately following the flaring activity. There is some indication
that the lightcurve may become steeper beyond approximately 10 ks.
Based on a preliminary spectral fit to the PC data in the time region
between 200-5000 seconds, the spectrum can be described by an absorbed
power law, with a power law photon index of 1.9 +/- 0.2 and N_H of 10e20
+/- 5e20 cm^-2. The 0.2-10 keV flux during this time frame is estimated
to be approximately 4e-12 erg/cm^2/s.
This Circular is an official product of the Swift XRT Team.
GCN Circular 4667
Subject
GRB 060204b: Keck/LRIS Afterglow Confirmation
Date
2006-02-05T00:32:49Z (20 years ago)
From
S. Bradley Cenko at Caltech <cenko@srl.caltech.edu>
D-S. Moon and S. B. Cenko (Caltech) report on behalf of a larger
collaboration:
We have imaged the field of GRB060204b (Falcone et al., GCN 4655) with the
Low-Resolution Imaging Spectrometer mounted on the 10-m Keck I telescope.
Observations consisted of 12 x 180 s images taken simultaneously in V and
I, beginning approximately 18 minutes after the burst. We clearly detect
the afterglow candidate proposed by Guidorzi et. al (GCN 4661).
Furthermore, the object fades by approximately 1.4 magnitudes during our
I-band observations, and we therefore confirm that this object is the
afterglow of GRB060204b. In our first I-band image, the afterlow had a
magnitude of 19.4 +/- 0.3 (calculated with respect to the USNO-B1
catalog).
GCN Circular 4661
Subject
GRB060204B: Faulkes OT candidate
Date
2006-02-04T17:29:02Z (20 years ago)
From
Cristiano Guidorzi at ARI,Liverpool JMU <crg@astro.livjm.ac.uk>
C. Guidorzi, C.G. Mundell, R.J. Smith, A. Monfardini,
A. Gomboc,I. A. Steele, C.J. Mottram, M.F. Bode (Liverpool JMU),
E. Rol, P. O'Brien, N. Bannister (Leicester) report:
"The 2-m Faulkes Telescope North followed up GRB060204B
(SWIFT trigger 180241) 46.2 min after the GRB trigger time.
We detect a new source in R and i' filters not present in the
SDSS pre-burst images (Cool et al., GCN 4657) at the following
position:
14:07:14.9 27:40:36.4 (J2000)
with a magnitude R = 20.4 +- 0.4 mag (vs USNOB1), from 46.2 min to 57.0
min after the burst, and i'=20.1 +- 0.3 (vs SDSS i' band image),
from 53.2 min to 58.8 min after the burst trigger time.
The source lies inside the XRT error circle (Falcone et al. GCN 4655)."
GCN Circular 4660
Subject
GRB 060204B: ART optical limit
Date
2006-02-04T17:14:52Z (20 years ago)
From
Ken ichi Torii at RIKEN <torii@ess.sci.osaka-u.ac.jp>
K. Torii (Osaka U.) reports on behalf of the ART collaboration:
The error region of GRB 060204B (Falcone et al. GCN 4655) was imaged
with the 0.35m ART 3b telescope in Toyonaka, Osaka.
From a stacked frame (60s x 20 in Ic), the following 3 sigma limit is
derived for an optical counterpart of the XRT source (GCN 4655), with
reference to USNO-B1.0 I magnitude.
-----------------------------
StartUT Limits
=============================
14:59:31 >18.0I
=============================
GCN Circular 4658
Subject
GRB060204B, optical observation
Date
2006-02-04T16:51:42Z (20 years ago)
From
Eri Sonoda at U of Miyazaki/Japan <sonoda@astro.miyazaki-u.ac.jp>
E.Sonoda,S.Maeno,Y.Nakamura,S.Masuda,M.Yamauchi
(University of Miyazaki)
We have observed the field covering the error circle of
GRB060204B (GCN 4655) with the unfiltered CCD camera on
the 30-cm telescope at University of Miyazaki.
The observation was started 14:44:39 UT, 10.25 min
after the Swift trigger time.
We have compared our data of 30 sec exposures
with the USNO-A2.0 catalog,
the upper limits are as follows:
--------------------------------------------------------------
Start(UT) End(UT) Num. of frames Limit (mag.)
--------------------------------------------------------------
14:44:39 14:45:09 1 ~15.1
14:44:39 14:48:48 6 ~16.34
---------------------------------------------------------------
GCN Circular 4657
Subject
GRB060204B - SDSS pre-burst observations
Date
2006-02-04T16:47:26Z (20 years ago)
From
Richard J. Cool at U.of AZ/Steward Obs <rcool@as.arizona.edu>
Richard J. Cool (Arizona), Daniel J. Eisenstein (Arizona), David
W. Hogg (NYU), Michael R. Blanton (NYU), David J. Schlegel
(LBNL), J. Brinkmann (APO), Donald P. Schneider (PSU), and
Daniel E. Vanden Berk (PSU) report:
The Sloan Digital Sky Survey (SDSS) imaged the field of burst
GRB060204B 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/GRB060204B
We supply FITS images in each of the 5 SDSS bands of a 8'x8'
region centered on the GRB position (ra=211.795 (14:07:10.8),
dec=27.6830 (27:40:58.8); Swift-BAT TRIGGER 180241), 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 GRB060204B_sdss.calstar.dat, we report photometry
and astrometry of 297 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 GRB060204B_sdss.objects_flux.dat and
GRB060204B_sdss.objects_magnitudes.dat, we report photometry
of 629 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 GRB060204B_sdss.objects_flux.dat are in nanomaggies while
the magnitudes listed in GRB060204B_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=0.101 mag, A_g=0.074 mag,
A_r = 0.054 mag, A_i=0.041 mag, and A_z=0.029 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/dr4.
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, in press,
astro-ph/0507711), when using the data or referring to the
technical documentation.
GCN Circular 4655
Subject
GRB 060204B: Swift detection of a burst
Date
2006-02-04T15:26:50Z (20 years ago)
From
Scott Barthelmy at NASA/GSFC <Scott@lheamail.gsfc.nasa.gov>
A. Falcone (PSU), L. Barbier (GSFC), S. Barthelmy (GSFC),
D. Burrows (PSU), J. Cummings (GSFC/NRC), N. Gehrels (GSFC),
S. Hunsberger (PSU), J. Kennea (PSU), H. Krimm (GSFC/USRA),
F. Marshall (GSFC), D. Morris (PSU), D. Palmer (LANL),
E. Rol (U Leicester), T. Sakamoto (GSFC)
on behalf of the Swift team:
At 14:34:24 UT, Swift-BAT triggered and located GRB 060204B (trigger=180241).
The spacecraft slewed immediately. The BAT on-board calculated location is
RA,Dec 211.795d,+27.683d {14h 07m 11s,+27d 40' 60"} (J2000), with an uncertainty
of 3 arcmin (radius, 90% containment, stat+sys). There is missing data
in the BAT TDRSS lightcurve message, so we can not say anything about the
lightcurve at this initial quicklook. However, it appears to be a long burst.
We will have to wait for the full Malindi data download.
The spacecraft slewed promptly and the XRT began observing the GRB at
14:35:59 UT, 94.5 sec after the BAT trigger. A bright, uncatalogued,
flaring source was found by the on-board centroiding algorithm at
RA(J2000)=+14h 07m 14.6s
DEC(J2000)=+27d 40' 34"
with an uncertainty of 6 arcseconds radius (90% containment).
This position lies 57 arcseconds from the center of the BAT error circle.
UVOT took a finding chart exposure of 200 seconds with the V filter
starting 101 seconds after the BAT trigger. No afterglow candidate has
been found in the initial data products. The 2.7'x2.7' sub-image covers
100% of the XRT error circle. The typical 3-sigma upper limit has been
about 18th 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.
We note there is a cluster of galaxies at z=0.156 in this field.
Even though the initial Notices went out with the Star Tracker Loss-of-Lock
flag set, ground analysis has shown that the s/c was tracking accurately
and that the position is good.
We are currently in the Malindi telemetry downlink gap. We will not have
further data for another 8 hours.