GRB 070129
GCN Circular 6053
Subject
GRB 070129: Swift detection of a burst
Date
2007-01-29T23:49:36Z (18 years ago)
From
David Burrows at PSU/Swift <dxb15@psu.edu>
O. Godet (U Leicester), D. N. Burrows (PSU), M. M. Chester (PSU),
S. T. Holland (CRESST/GSFC/USRA), J. A. Kennea (PSU),
C. B. Markwardt (GSFC/UMD), K. M. McLean (LANL/UTD),
K. L. Page (U Leicester), D. M. Palmer (LANL),
T. Sakamoto (NASA/ORAU), M. Stamatikos (NASA/ORAU),
R. L. C. Starling (U Leicester), E. Troja (INAF-IASFPA),
D. E. Vanden Berk (PSU) and S. D. Vergani (DIAS-DCU) report on behalf
of the Swift Team:
At 23:35:10 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 070129 (trigger=258408). Swift slewed immediately to the burst.
The BAT on-board calculated location is
RA, Dec 37.014, +11.697 which is
RA(J2000) = 02h 28m 03s
Dec(J2000) = +11d 41' 51"
with an uncertainty of 3 arcmin (radius, 90% containment, including
systematic uncertainty). The BAT light curve shows no obvious
variation in the count rate, which is not uncommon for image
triggers.
The XRT began observing the field at 23:37:23 UT, 134 seconds after the
BAT trigger. XRT found a bright, fading, uncatalogued X-ray source
located at RA, Dec 37.0033, +11.6852 which is
RA(J2000) = 02h 28m 00.7s
Dec(J2000) = 11d 41' 06.7"
with an uncertainty of 4.7 arcseconds (radius, 90% containment).
This location is 57 arcseconds from the BAT on-board position,
within the BAT error circle. The initial flux in the 2.5s image
was 3.3e-09 erg/cm2/s (0.2-10 keV).
UVOT took a finding chart exposure of 100 seconds with the White (160-650 nm)
filter starting 143 seconds after the BAT trigger. No afterglow candidate has
been found in the initial data products. The overlap of the sub-image and the
XRT error circle is 100%. 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 mag. No correction has been made for the
expected extinction corresponding to E(B-V) of 0.14.
GCN Circular 6055
Subject
GRB 070129: VLT observations
Date
2007-01-30T12:13:19Z (18 years ago)
From
Daniele Malesani at Niels Bohr Inst,Dark Cosmology Center <malesani@astro.ku.dk>
Daniele Malesani (Dark, NBI), Pall Jakobsson (Univ. Hertfordshire), Paul
M. Vreeswijk (ESO), Anreas O. Jaunsen (Univ. Oslo), and D. Alexander Kann
(TLS Tautenburg), report on behalf of a larger collaboration:
Using FORS2 on the ESO Very Large Telescope, we have imaged the GRB 070129
field (Godet et al., GCN 6053) on Jan 30.07 UT (2.15 hours post-burst).
Inside the refined XRT circle (Butler 2006, AJ, in press,
astro-ph/0611031; DSS catalog; version 0.2) we find an R ~ 21.3 mag
source. At present we cannot assess the source variability. It is possibly
extended but not readily visible in the DSS.
Its coordinates are:
R.A.(J2000) = 02:28:00.94
Dec(J2000) = +11:41:04.0
with a error of 0.2" in each coordinate.
An image of the field is shown at:
http://star-www.herts.ac.uk/~palli/GRB070129.jpg
We thank the Paranal staff, especially Elena Valenti, Paul Lynam and
Leonardo Vanzi, for excellent support.
[GCN OPS NOTE(03feb07): Per author's request, the sign on the
declination was changed from minus to plus.]
GCN Circular 6056
Subject
GRB 070129: Swift-XRT Refined Analysis
Date
2007-01-30T12:27:36Z (18 years ago)
From
Olivier Godet at U.of Leicester <og19@star.le.ac.uk>
O. Godet, K. Page, P. Evans, J. Osborne (U. Leicester), D. N. Burrows
(PSU) report on behalf of the Swift XRT team:
We analysed the first 5 orbits of XRT data from GRB 070129 (from T0+140s
to T0+24749s). An 11ks photon counting (PC) mode image provides a
refined XRT position:
RA(J2000) = 02h 28m 00.83s
Dec(J2000) = +11d 41' 05.1''
with an uncertainty of 3.6 arcsec (90% containment). This position is
within the BAT error circle and is 2.5 arcsec away from the on-board XRT
position quoted in Godet et al. (GCN 6053) and includes the latest XRT
boresight correction. We note that our error circle includes the
position of the source reported in Malesani et al. 2007 (GCN 070129).
The BAT triggered on a precursor and saw the main burst around T0+380s.
The XRT started to observe the field 140s after the BAT trigger (T0).
The X-ray light curve shows the main burst consisting of several X-ray
flares from T0+140s to T0+700s, followed by a steep decay to T0+1200s
and then a flatter decay (so far to T0+24749s). This flatter decay can
be fitted by a single power-law with a decay slope of alpha = 0.33
+0.09/-0.10.
The Windowed Timing (WT) data correspond to the main burst, which shows
strong spectral evolution. An absorbed power-law fit of the WT data
(first orbit) from T+140s to T+792s gives a photon index of 1.81+/-0.03
and an absorption value of (2.1 +/-0.1)e21 cm**-2, compared to the
Galactic value of 8.4e20 cm**-2 in the burst direction. The error are
given at a 90% confidence level. The spectrum of the PC data from T0
+795s to T0+24749s can be fit by an absorbed power-law with Gamma = 2.39
+0.22/-0.19 and an absorption value of (1.6 +/-0.5)e21 cm**-2.
If the burst continues decaying at the current rate (alpha = 0.33) we
estimate an XRT count rate of 0.042 counts/s at T0 + 24hr, which
corresponds to an observed 0.3-10.keV flux of 2.5e-12 ergs cm**-2 s**-1
and an unabsorbed flux of 2.9e-12 ergs cm**-2 s**-1.
This circular is an official product of the Swift XRT Team.
GCN Circular 6057
Subject
GRB 070129: Xinglong TNT optical Upper Limit
Date
2007-01-30T15:52:59Z (18 years ago)
From
W.K. Zheng at NAOC <zwk@bao.ac.cn>
L.P. Xin, M.Zhai, Y.L. Qiu, J.Y. Wei, J.Y. Hu, J.S. Deng,
Y. Urata, J.Z. Li and W.K. Zheng on behalf of EAFON report:
We have imaged the field of GRB 070129(Godet et al. GCN6053) with the
TNT 0.8m telescope at Xinglong Observatory 11.98 hours after the burst.
Totally 10*300s R band images were obtained. The source identified by
Daniele Malesani et al.(GCN 6055,we assume the Dec coordinate reported
in this GCN is Dec(J2000) = +11:41:04.0) was not seen in our combined
image, and no new source was find in the refined XRT circle,the 3-sigma
limit is ~21.1 derieved form USNO A-2.0.
This message may be cited.
GCN Circular 6058
Subject
GRB 070129, Swift-BAT refined analysis of a particularly long
Date
2007-01-30T16:31:09Z (18 years ago)
From
Hans Krimm at NASA-GSFC <krimm@milkyway.gsfc.nasa.gov>
H. Krimm (GSFC/USRA), L. Barbier (GSFC), S. D. Barthelmy (GSFC),
J. Cummings (GSFC/UMBC), E. Fenimore (LANL), N. Gehrels (GSFC),
O. Godet (U Leicester), C. Markwardt (GSFC/UMD), D. Palmer (LANL),
A. Parsons (GSFC), T. Sakamoto (GSFC/ORAU), G. Sato (GSFC/ISAS),
M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC)
on behalf of the Swift-BAT team:
Using the data set from T-239.0 to T+963.1 sec from the recent telemetry
downlink, we report further analysis of BAT GRB 070129
(trigger #258408) (Godet, et al., GCN Circ. 6053). The BAT
ground-calculated position is RA, Dec = 37.001, 11.730 deg which is
RA(J2000) = 2h 28m 0.3s
Dec(J2000) = +11d 43' 46.7"
with an uncertainty of 2.6 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 41%.
The mask-tagged light curve showed that the trigger was on a precursor to
the main burst which started at approximately T+200 sec, coincident with
the detections reported in the XRT (Godet et al, GCN 6056). Emission
started at ~T-180 sec, then continued through a series of peaks out
to ~T+160 sec, where there was a dip in the light curve preceding the main
peak of the prompt emission which lasted until T+380 sec.
This was followed by some possible low level emission out to ~T+600 sec.
T90 (15-350 keV) is 460 +- 20 sec (estimated error including systematics).
The time-averaged spectrum from T-125.0 to T+373.9 is best fit by
a simple power-law model. The power law index of the time-averaged
spectrum is 2.05 +- 0.16. The fluence in the 15-150 keV band is
3.1 +- 0.3 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from
T+361.46 sec in the 15-150 keV band is 0.6 +- 0.1 ph/cm2/sec.
All the quoted errors are at the 90% confidence level.
GCN Circular 6062
Subject
GRB070129: MITSuME optical observation
Date
2007-01-31T06:31:04Z (18 years ago)
From
Nobuyuki Kawai at Tokyo Tech <nkawai@hp.phys.titech.ac.jp>
T. Ishimura, Y. Yatsu, T. Shimokawabe, N. Vasquez, and N. Kawai
(Tokyo Tech) report on behalf of the MITSuME collaboration:
We observed the error box of GRB070129 (Godet et al., GCN 6053)
with the 3-color 50cm MITSuME Telescope at Akeno, Japan
starting at 9:44:12 UT, 10.1 hours after the trigger.
In the co-added images of Ic, Rc, and g' bands, we did not detect
the afterglow . The 3-sigma limiting magnitudes based on USNO-B1.0
(I-band) and NOMAD (R-band,g'-band) stars are following.
Filter start time end time Exp(s) Mag (3-sigma upper limit)
-----------------------------------------------------------------
Ic 9:44:12 10:22:57 60s * 25 18.4
Rc 9:44:12 10:22:57 60s * 25 19.0
g' 9:44:12 10:22:57 60s * 25 19.4
-----------------------------------------------------------------
GCN Circular 6065
Subject
GRB 070129: dust-scattered X-ray halo detected by Swift/XRT
Date
2007-01-31T14:31:35Z (18 years ago)
From
Sandro Mereghetti at IASF/CNR <sandro@iasf-milano.inaf.it>
G. Vianello (INAF, IASF-Milano & Univ. dell'Insubria), A. Tiengo, S.
Mereghetti (INAF, IASF-Milano) report:
We discovered a faint dust scattering halo in the Swift XRT Photon
Counting mode data of GRB 070129. The halo consists of a partial ring of
radius ~2 arcmin located to the North-West of the GRB afterglow position.
Analysis of the dynamical image (see Tiengo & Mereghetti 2006 A&A 449,
203) covering the period from T0+4700s to T0+7300s (where T0 is the BAT
trigger time, as reported in GCN 6053) indicates that the halo is
expanding and leads to an estimate of ~300 pc for the distance of the dust
layer responsible for the scattering.
Dust maps (Schlegel, Finkbeiner, & Davis 1998, ApJ, 500, 525) show a
diffuse structure in the direction indicated by the partial ring, and a
total Galactic extinction of A_v~0.4.
GCN Circular 6066
Subject
GRB 070129: Swift/UVOT Upper limits
Date
2007-01-31T15:31:00Z (18 years ago)
From
Margaret Chester at PSU <chester@astro.psu.edu>
M. M. Chester (PSU) and O. Godet (U. Leicester) report on behalf
of the Swift UVOT team:
The Swift/UVOT observed the field of GRB 070129 starting 124 s
after the BAT trigger (Godet et al. 2007, GCN Circ. 6053). We do
not find any source, in any of the UVOT observations, inside the
refined XRT error circle (Godet et al., 2007 GCN Circ. 6056).
The 3-sigma upper limits for detecting a source inside the XRT
error circle in the V-band settling image, the finding-chart
exposures, and the co-added frames are:
Filter T_start T_stop Exp(s) Mag (3-sigma UL)
-----------------------------------------------------------------
V settling 124 133 9 17.3
V finding 247 647 400 19.2
V finding 979 1379 400 19.8
White finding 142 242 100 19.7
White finding 873 973 100 20.0
V 124 47339 3046 20.7
B 726 53670 3073 21.4
U 701 53414 5398 21.3
UVW1 678 52501 4895 22.2
UVM2 653 58021 3956 22.0
UVW2 754 46426 2239 22.0
White 143 13183 1460 20.8
-----------------------------------------------------------------
The values quoted above are not corrected for the expected Galactic
extinction corresponding to a reddening of E_{B-V} = 0.14 mag towards
the direction of the burst (Schlegel et al. 1998).
GCN Circular 6070
Subject
GRB 070129: afterglow confirmation
Date
2007-02-03T07:55:02Z (18 years ago)
From
Daniele Malesani at Niels Bohr Inst,Dark Cosmology Center <malesani@astro.ku.dk>
D. Malesani (Dark/NBI), P.M. Vreeswijk (ESO), P. Jakobsson (Univ.
Hertfordshire), J.P.U. Fynbo (Dark/NBI), D.A. Kann (TLS Tautenburg), G.
Micheva (Stockolm Obs.), J. Holopainen (Turku Univ.), report on behalf of
a larger collaboration:
We have observed the field of GRB 070129 (Godet et al., GCN 6053) with the
NOT telescope equipped with StanCam. R-band observations were carried out
starting on 2007 Feb 2.822 UT (mean time 2.828 UT, i.e. 3.84 days after
the GRB).
The object seen in our VLT images and lying inside the XRT error circle
(Malesani et al., GCN 6055) has clearly faded (by at least 2 mag). It is
no longer visible in the new images. It is thus the afterglow of GRB
070129. Its location is consistent with the refined XRT position (Godet et
al., GCN 6056).
We also report the object coordinates (J2000):
RA = 02:28:00.94
Dec = +11:41:04.0
In our previous circular (GCN 6055), the declination was incorrectly
reported as being "-11", as first pointed out by Xin et al. (GCN 6057). We
apologize for any inconvenience this may have caused.
GCN Circular 6097
Subject
GRB 070129: MDM I-band Detection
Date
2007-02-11T20:54:06Z (18 years ago)
From
Jules Halpern at Columbia U. <jules@astro.columbia.edu>
J. P. Halpern, N. Mirabal (Columbia U.), & J. R. Thorstensen (Dartmouth)
report on behalf of the MDM Observatory GRB follow-up team:
"We observed the field of GRB 070129 (Godet et al., GCNs 6053, 6056) in
the I-band using the MDM 2.4m telescope on Jan. 30 from 02:14-02:43 UT,
or 2.65-3.14 hr after the burst. The optical transient (OT) discovered
with the VLT at 2.15 hr post-burst (Malesani et al., GCNs 6055, 6070)
with R~21.3 is also present in our images, with magnitude I=20.60+/-0.04.
The latter is referenced to a star 27" west of the OT that has I=17.57
in the USNO B1.0 catalog. An image is posted at
http://www.astro.columbia.edu/~jules/grb/070129
This message may be cited."