GRB 070529
GCN Circular 6466
Subject
GRB 070529: Swift detection of a burst with an optical aterglow
Date
2007-05-29T13:13:10Z (18 years ago)
From
David Palmer at LANL <palmer@lanl.gov>
S. T. Holland (CRESST/GSFC/USRA), L. M. Barbier (NASA/GSFC),
S. D. Barthelmy (GSFC), P. J. Brown (PSU), S. Campana (INAF-OAB),
G. Cusumano (INAF-IASFPA), P. A. Evans (U Leicester),
N. Gehrels (NASA/GSFC), O. Godet (U Leicester), C. Gronwall (PSU),
C. Guidorzi (Univ Bicocca&INAF-OAB), H. A. Krimm (GSFC/USRA),
V. La Parola (INAF-IASFPA), V. Mangano (INAF-IASFPA),
F. E. Marshall (NASA/GSFC), J. P. Osborne (U Leicester),
K. L. Page (U Leicester), D. M. Palmer (LANL),
P. Romano (Univ. Bicocca & INAF-OAB), G. Sato (GSFC/ISAS),
B. Sbarufatti (INAF-IASFPA), R. L. C. Starling (U Leicester),
G. Tagliaferri (INAF-OAB), E. Troja (INAF-IASFPA),
D. E. Vanden Berk (PSU), S. D. Vergani (DIAS-DCU), L. Vetere (PSU)
and H. Ziaeepour (UCL-MSSL) report on behalf of the Swift Team:
At 12:48:28 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 070529 (trigger=280706). Swift slewed immediately to the burst.
The BAT on-board calculated location is
RA, Dec 283.750, +20.639 which is
RA(J2000) = 18h 55m 00s
Dec(J2000) = +20d 38' 21"
with an uncertainty of 3 arcmin (radius, 90% containment, including
systematic uncertainty). The BAT light curve showed a multi-peaked
structure at least 40 seconds long. The peak count rate
was ~1500 counts/sec (15-350 keV), at ~2 sec after the trigger.
The XRT began observing the field at 12:50:39 UT, 131 seconds after the
BAT trigger. XRT found a moderately bright, uncatalogued X-ray source.
From downlinked data, we determined the position RA, Dec 283.7427, +20.6586
which is
RA(J2000) = 18h 54m 58.26s
Dec(J2000) = +20d 39' 31.04"
with an uncertainty of 3.7 arcseconds (radius, 90% containment).
This location is 76 arcseconds from the BAT on-board position,
within the BAT error circle. The initial flux in the 2.5s image
was 7.2e-10 erg/cm2/s (0.2-10 keV).
UVOT took a finding chart exposure of 400 seconds with the V filter
starting 134 seconds after the BAT trigger. There is an afterglow
candidate with V=17.4 mag located at RA, Dec 283.7425, +20.6594 which
is
RA(J2000) = 18h 54m 58.19s
Dec(J2000) = 20d 39' 34.0" with
an uncertainty of 0.5 arcsec (radius, 90% containment). The 2.7'x2.7'
sub-image covers 100% of the XRT error circle. No correction has been
made for the expected extinction of about 1.0 magnitudes.
GCN Circular 6467
Subject
GRB 070529: Xinglong TNT Optical Upper Limit
Date
2007-05-29T16:40:25Z (18 years ago)
From
W.K. Zheng at NAOC <zwk@bao.ac.cn>
Y.Q. Lou, X.F. Wang, L.P. Xin, M.Zhai, Y.L. Qiu, J.Y. Wei, J.Y. Hu,
J.S. Deng, Y. Urata, and W.K. Zheng on behalf of EAFON report:
We have imaged the field of GRB 070529 (Holland et al., GCN 6466)
with the Xinglong TNT 80cm telescope. Observation was performed
with V and R band. We noticed this was a crowded field and we didn't
detect the OT (Holland et al., GCN 6466) in our combined images,
the R band 3 sigma upper limit is ~20.1 derived from USNO-B1.0 with
mean time 2.03 hours after the burst.
This message may be cited.
GCN Circular 6468
Subject
GRB 070529, Swift-BAT refined analysis
Date
2007-05-29T18:10:23Z (18 years ago)
From
Scott Barthelmy at NASA/GSFC <scott@lheamail.gsfc.nasa.gov>
A. Parsons (GSFC), L. Barbier (GSFC), S. D. Barthelmy (GSFC),
J. Cummings (GSFC/UMBC), E. Fenimore (LANL), N. Gehrels (GSFC),
S. T. Holland (CRESST/GSFC/USRA), H. Krimm (GSFC/USRA),
C. Markwardt (GSFC/UMD), D. Palmer (LANL), T. Sakamoto (GSFC/ORAU),
G. Sato (GSFC/ISAS), M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC),
T. Ukwatta (GWU)
on behalf of the Swift-BAT team:
Using the data set from T-119 to T+283 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 070529 (trigger #280706)
(Holland, et al., GCN Circ. 6466). The BAT ground-calculated position is
RA, Dec = 283.725, 20.648 deg which is
RA(J2000) = 18h 54m 54.0s
Dec(J2000) = 20d 38' 54"
with an uncertainty of 1.9 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 16%.
The mask-weighted lightcurve shows multiple overlapping peaks
starting at T_0 and lasting out T+120 sec. There is a possible (~4 sigma)
10-sec peak at ~T-55 sec. T90 (15-350 keV) is 109 +- 3 sec
(estimated error including systematics).
The time-averaged spectrum from T-1.2 to T+120.9 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
1.38 +- 0.16. The fluence in the 15-150 keV band is 2.6 +- 0.2 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+2.02 sec in the 15-150 keV band
is 1.4 +- 0.4 ph/cm2/sec. All the quoted errors are at the 90% confidence
level.
GCN Circular 6469
Subject
GRB 070529: Swift-XRT refined analysis
Date
2007-05-29T18:42:41Z (18 years ago)
From
Boris Sbarufatti at INAF-IASF-Pa <sbarufatti@ifc.inaf.it>
V. Mangano, B. Sbarufatti, V. La Parola (INAF-IASFPA),
S. T. Holland (CRESST/USRA/GSFC) report on behalf of the
Swift XRT team:
We have analysed the first two orbits of XRT data of GRB 070529
(Holland et al., GCN Circ. 6466) with total exposure time of
3.6 ks in Photon Counting mode.
The XRT position calculated on the second orbit data only,
in order to avoid pile-up effects is:
RA(J2000) = 18h 54m 58.2s
Dec(J2000) = 20d 39' 31.5"
with an uncertainty of 3.8 arcsec (radius, 90% containment).
This is 0.9 arcsec from the initial X-ray position, 69 arcsec
from the BAT refined position (Parsons et al., GCN Circ. 6468),
and 2.3 arcsec from the UVOT position (Holland et al.,
GCN Circ. 6466).
The XRT light curve follows a power-law decay with index
0.91 � 0.05 up to T+7 ks.
We extracted a spectrum of the PC data which can be fitted
with an absorbed power law with photon index of 2.2 � 0.2
and column density of (3.5+/-0.8) E21 cm-2, slightly in
excess with respect to the Galactic absorption column
(1.9E21 cm-2; Dickey & Lockman, 1990).
The absorbed (unabsorbed) 0.3-10.0 keV average flux
in the T+150 s - T+7 ks time interval is
1.6E-11 (2.8E-11) ergs cm-2 s-1.
Assuming that the source continues its decay at the present rate,
we predict an XRT count rate of 8.6E-3 counts/s at T+24 h, which
corresponds to an observed flux of 7E-13 ergs cm-2 s-1.
This circular is an official product of the Swift XRT team.
GCN Circular 6470
Subject
GRB 070529: Gemini Redshift
Date
2007-05-29T20:55:06Z (18 years ago)
From
Edo Berger at Carnegie Obs <eberger@ociw.edu>
E. Berger (Carnegie), D. B. Fox and A. Cucchiara (Penn State) report:
"Starting on 2007 May 29.59 UT we used GMOS on the Gemini North telescope
to obtain a 900 sec spectrum of the afterglow of GRB 050729 (GCN 6466).
The spectrum covers the wavelength range 5000-7900A. We find several
strong absorption features corresponding to CIV, SiII, FeII, AlII, AlIII,
etc. at a redshift of z=2.4996, which we identify as the redshift of the
burst. At this redshift the observed fluence of 2.6e-6 erg/cm^2 (GCN
6468) translates to an isotropic equivalent energy of 3.8e52 erg."
GCN Circular 6471
Subject
GRB 070529: Optical aterglow from MIRO
Date
2007-05-29T21:19:20Z (18 years ago)
From
Kiran S Baliyan at Physical Research Lab, Ahmedabad,India <baliyan@prl.res.in>
K.S. Baliyan, S. Ganesh and Priyanksha (MIRO-PRL, Ahmedabad,
India) report:
We observed the field around the location of GRB070529 (18h 54m
58.19s, 20d 39' 34.0"), BAT trigger no. 280706, at 14:48:28 UT
as reported by S. T. Holland on behalf of the Swift Team (GCN 6466).
We started observations at 18:10:08 UT with 1296*1152 CCD mounted on
the 1.2 M telescope of the Mt. Abu IR Observatory,
Gurushikhar, Mount Abu, Rajasthan, operated by Physical
Research Laboratory, Ahmedabad- India, in VR bands. A total of 12
images of 180 seconds exposure in R and 5 images in V band were
taken. The visual inspection shows a very faint source near the above
location in a very crowded field. Details will be reported after
proper analysis of all the images.
The message may be cited.
GCN Circular 6472
Subject
GRB 070529: MARGE Observations
Date
2007-05-30T02:38:59Z (18 years ago)
From
Heather Swan at U.of Michigan/ROTSE <hflewell@umich.edu>
H. Swan (U Mich), I. Smith (Rice), C. Akerlof (U Mich), and M.
Skinner (Boeing) report on behalf of the MARGE collaboration:
The AEOS Burst Camera (ABC) on the AEOS telescope, located at the
Maui Space Surveillance System on Haleakala, observed the fading
counterpart to GRB070529 (Swift trigger 280706 (GCN 6466)). The
images are unfiltered 10s exposures which started less than 30
minutes after the trigger and ended ~ 2 hours later.
We detect the OT first identified by S. T. Holland et al (GCN 6466).
A preliminary analysis gives a magnitude of approximately 19.41
+/-0.04 at 13:20:35 UT. We calibrated the OT to the USNO-B1.0 R2 band
magnitude of the nearby 17.35 mag star located at (J2000) RA =
283.73991, DEC = 20.657206. We find that the ABC data fades as a
power law decay with index ~-1.1.
Further analysis is in progress.
GCN Circular 6473
Subject
Swift/UVOT refined analysis of GRB070529
Date
2007-05-30T14:37:07Z (18 years ago)
From
Massimiliano de Pasquale at MSSL-UCL <mdp@mssl.ucl.ac.uk>
M. De Pasquale (MSSL/UCL) and S. T. Holland (CRESST/USRA/GSFC)
report, on the behalf of Swift UVOT team:
The Swift Ultraviolet/Optical telescope (UVOT) began its
initial V-band finding chart exposure of GRB070529 (Holland et al.,
GCN circ. 6466) 134 seconds after the trigger and the optical
afterglow is clearly detected inside the refined XRT error
circle (Mangano et al., GCN circ. 6469). Successively, the
optical source appears to fade with a decay slope, based
on the V band datapoints, of about -1.8.
In the following table, we report the magnitudes and 3 sigma
upper limits for this source. Errors are at 1 sigma level.
Filter Time (s) Exp(s) Mag
V 134-534 393 17.1 +/- 0.1
V 652-1253 420 19.3 +/- 0.4
V 40339-47072 2039 > 20.4
B 613-758 20 > 18.8
U 588-6277 439 > 20.1
UW1 564-7038 459 > 20.5
UM2 540-7038 592 > 20.8
UW2 628-6687 432 > 21.0
No observation was performed in the white filter,
due to the crowded field.
No correction has been made for the considerable
Galactic reddening toward the burst, E(B-V)=0.3
(Schlegel et al. 1998).
GCN Circular 6474
Subject
GRB 070529: SARA upper limit
Date
2007-05-30T22:04:44Z (18 years ago)
From
Adria C. Updike at Clemson U <aupdike@clemson.edu>
A. C. Updike and D. H. Hartmann (Clemson University) report on behalf of
the Clemson GRB Follow-Up Team:
We observed the field of GRB 070529 (GCN 6466, Holland et al.) with the
0.9m SARA telescope at KPNO. Under decent weather conditions, we imaged
the field from 06:14:58 UT, 17 hours and 26 minutes after the burst,
until 07:52:12 UT. We obtained a total of 50 min of R-band exposures.
In the stacked image at the location of the afterglow identified in UVOT
observations (GCN 6466), we detect no new object to a limiting magnitude
of R = 19.0 +/- 0.2.
The SARA Homepage can be found at:
http://saraobservatory.org
This message may be cited.