GRB 060109
GCN Circular 4455
Subject
GRB 060109: Swift Detection of a long burst
Date
2006-01-09T17:31:48Z (19 years ago)
From
Jay R. Cummings at NASA/GSFC/Swift <jayc@milkyway.gsfc.nasa.gov>
M. De Pasquale (MSSL), S. Barthelmy (GSFC), A. Beardmore (U. Leicester),
J. Cummings (GSFC/ORAU), N. Gehrels (GSFC), M.R. Goad (U. Leicester),
O. Godet (U. Leicester), J. Kennea (PSU), H. Krimm (GSFC/USRA),
F. Marshall (GSFC), K. Page (U. Leicester), D. Palmer (LANL),
T. Sakamoto (GSFC),
on behalf of the Swift Team:
At 16:54:41 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 060109 (trigger=176620). The BAT on-board calculated
location is RA,Dec 282.710, +31.989 {18h 50m 50s, +31d 59' 22"} (J2000)
with an uncertainty of 3 arcmin (radius, 90% containment, including
systematic uncertainty). The BAT light curve showed a multi-peaked
structure with a duration of about 10 sec. The peak count rate was
~1000 counts/sec (15-350 keV), at ~8 sec after the trigger.
The XRT began observing the burst at 16:56:22 UT, 101 sec after the BAT
trigger. A bright (0.2-10 keV flux of 4.8e-09 erg/cm2/sec), fading,
uncatalogued source was found by the on-board centroiding algorithm at
RA(J2000)= 18h 50m 43.9s
DEC(J2000)= +31d 59' 34.7"
with an uncertainty of 5.8 arcsec radius (90% containment). This
uncertainty includes a systematic error of about 5 arcsec in the
on-board calculated positions due to the XRT boresight offset. This
position lies 84 arcsec from the centre of the BAT error circle.
UVOT took a finding chart exposure of 200 seconds with the V filter
starting 104 sec 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 19.0 mag. No correction has been made for
the expected visual extinction of about 0.5 magnitudes.
GCN Circular 4460
Subject
GRB060109, optical observation
Date
2006-01-10T00:49:00Z (19 years ago)
From
Shouta Maeno at U.of Miyazaki <shouta@astro.miyazaki-u.ac.jp>
S.Maeno,E.Sonoda,S.Masuda,Y.Nakamura,M.Yamauchi
(University of Miyazaki)
"We have observed the field covering the error circle of
GRB 060109 (GCN 4455) with the unfiltered CCD camera on
the 30-cm telescope at University of Miyazaki.
The observation was started 20:10:19 UT on Jan.09.
After co-adding a set of 6 images (20:10:19 - 20:18:06 UT)
of 30 sec exposures, we have compared with the USNO A2.0 catalog.
Preliminary analysis shows there is no new source brighter
than 17.4mag."
GCN Circular 4461
Subject
GRB 060109: Swift/UVOT upper limits
Date
2006-01-10T05:54:08Z (19 years ago)
From
Alexander Blustin at MSSL-UCL <ajb@mssl.ucl.ac.uk>
A. J. Blustin (UCL-MSSL), M. De Pasquale (UCL-MSSL), S. R. Rosen
(UCL-MSSL), L. Cominsky (Sonoma State U.), J. Norris (GSFC),
N. Gehrels (GSFC) on behalf of the Swift/UVOT team
The Swift/UVOT began observing the field of GRB 060109 at 16:56:13 UT
on 2006-01-09 whilst settling on the target, 92 s after the BAT trigger
(De Pasquale et al., GCN 4455). No new source is detected at the XRT
position (reported by De Pasquale et al.) in coadded images with any of
the filters down to the following 3-sigma magnitude upper limits. These
values are not corrected for Galactic extinction; E(B-V) = 0.144.
Filter T_range(s) Exp(s) 3sigUL(mag)
V 92-22100 1449 20.0
B 312-18155 1132 20.8
U 637-17925 1038 20.5
W1 613-17696 1001 19.9
M2 589-22330 1233 20.3
W2 542-21871 1262 19.9
White 517-18385 1018 20.9
GCN Circular 4462
Subject
GRB 060109: Refined Swift-XRT analysis
Date
2006-01-10T08:15:16Z (19 years ago)
From
Kim Page at U.of Leicester <kpa@star.le.ac.uk>
A.P. Beardmore, K.L. Page (U.Leicester), J. Kennea (PSU), M. De Pasquale
(UCL-MSSL), P. Meszaros, M. Chester (PSU) report on behalf of the Swift
XRT team:
We have analysed the first four orbits of Swift-XRT data from GRB 060109.
8.3ks of PC mode data give a refined position of
RA(J2000) = 18h 50m 43.5s
Dec(J2000) = +31d 59' 29.7"
with an estimated uncertainty of 3.2 arcsec (90% containment). This
position is 7.7 arcsec away from the on-board XRT position quoted in De
Pasquale et al. (GCN 4455) and includes the latest XRT boresight
correction.
The X-ray lightcurve shows a steeply declining early phase, with a decay
slope of 5.1, which breaks to a shallower slope of 0.14 at about 300s.
This is followed by a second break at 6100s to a slope of 1.2.
The X-ray spectrum 100s to 200s after the BAT trigger can be fitted with
an absorbed power-law with a photon index of 1.85+/-0.09 and a column
density consistent with the Galactic value in this direction of 1.0e21
cm**2. The observed (unabsorbed) 0.3-10.0 keV flux over this interval is
5.1E-10 (6.2E-10) ergs cm**-2 s**-1.
If the source continues to fade at the current rate we predict an XRT
count rate of 0.006 counts/s 24hrs after the trigger, which corresponds
to an observed (0.3-10 keV) flux of 2.4e-11 ergs cm**-2 s**-1.
GCN Circular 4466
Subject
Correction to GRB 060109 XRT analysis
Date
2006-01-10T09:25:19Z (19 years ago)
From
Kim Page at U.of Leicester <kpa@star.le.ac.uk>
K.L. Page, A.P. Beardmore (U. Leicester), D. Fox (PSU) and M. De Pasquale
(UCL-MSSL) report on behalf of the Swift-XRT team:
The predicted observed flux at 24 hours for GRB 060109 is 2.4e-13 erg
cm^-2 s^-1. The value in GCN 4462 was incorrectly given as being 2 orders
of magnitude higher. We apologise for any confusion.
GCN Circular 4476
Subject
GRB 060109: Swift-BAT refined analysis
Date
2006-01-11T00:21:10Z (19 years ago)
From
Takanori Sakamoto at NASA/GSFC <takanori@milkyway.gsfc.nasa.gov>
D. Palmer (LANL), M. Ajello (MPE), L. Barbier (GSFC), S. Barthelmy (GSFC),
J. Cummings (GSFC/ORAU), E. Fenimore (LANL), R. Fink (GSFC),
N. Gehrels (GSFC), D. Hullinger (UMD), H. Krimm (GSFC/USRA),
C. Markwardt (GSFC/UMD),A. Parsons (GSFC), T. Sakamoto (GSFC/ORAU),
G. Sato (ISAS), J. Tueller (GSFC),
on behalf of the Swift-BAT team:
Using the data set from T-299.2 to T+302.9 sec from the recent telemetry
downlink, we report further analysis of BAT GRB 060109
(trigger #176620) (De Pasquale, et al., GCN 4455).
The BAT ground-calculated position
is (RA,Dec) = 282.739, 32.009 {18h 50m 57.3s, 32d 0' 32.6"} (deg; J2000)
+- 3.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 92%.
The mask-tagged lightcurve shows a double peak structure. The first peak has
a duration of ~20 sec. starting from T-2 sec. And the second peak has
a duration of ~40 sec. starting from T+75 sec.
T90 (15-350 keV) is (116 +- 3) sec (estimated error including systematics).
Over the full burst interval (T-0.4 to T+126.8 sec), the power law index of
the time-averaged spectrum is 1.96 +- 0.25. The fluence in the 15-150 keV
band is (6.4 +- 1.0) x 10^-07 erg/cm2. The 1-sec peak photon flux measured
from T+90.19 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 5279
Subject
GRB 060109: Upper Limit on Host Galaxy
Date
2006-06-27T18:54:50Z (19 years ago)
From
Alexander Kann at TLS Tautenburg <kann@tls-tautenburg.de>
D. A. Kann (Thueringer Landessternwarte Tautenburg) and S. Manohar (USC,
Los Angeles), report:
We observed the field of GRB 060109 (Pasquale et al., GCN 4455) with the
Tautenburg 1.34m Schmidt telescope under good observing conditions. We
obtained 11 x 600 sec images in the Rc filter for a total integration time
of 110 minutes. The mean observation time was June 27.9920 UT, which is
168.2 days after the burst. We determine the zero point of the image in
comparison with nine unsaturated and isolated stars of the USNOB1.0
catalog. Astrometry is also performed against the USNOB1.0 catalog.
At the refined position of the X-ray afterglow (Beardmore et al., GCN
4462), we do not detect any sources. The 2 sigma limiting magnitude of the
image is Rc=23.5. This magnitude is not corrected for the moderate
foreground extinction, E(B-V)=0.144.
This message may be cited.