GRB 090111
GCN Circular 8795
Subject
GRB 090111: Swift detection of a burst
Date
2009-01-12T00:15:21Z (16 years ago)
From
David Palmer at LANL <palmer@lanl.gov>
T. Sakamoto (NASA/UMBC), M. M. Chester (PSU), E. A. Hoversten (PSU),
H. A. Krimm (CRESST/GSFC/USRA), J. Mao (INAF-OAB),
R. Margutti (Univ Bicocca&OAB), F. E. Marshall (NASA/GSFC),
D. M. Palmer (LANL), M. Stamatikos (NASA/ORAU),
T. N. Ukwatta (GSFC/GWU) and L. Vetere (PSU) report on behalf of the
Swift Team:
At 23:58:21 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 090111 (trigger=339696). Swift slewed immediately to the burst.
The BAT on-board calculated location is
RA, Dec 251.645, +0.091 which is
RA(J2000) = 16h 46m 35s
Dec(J2000) = +00d 05' 28"
with an uncertainty of 3 arcmin (radius, 90% containment, including
systematic uncertainty). The BAT light curve showed a double-peaked
structure with a duration of about 30 sec. The peak count rate
was ~1200 counts/sec (15-350 keV), at ~0 sec after the trigger.
The XRT began observing the field at 23:59:38.3 UT, 76.6 seconds after
the BAT trigger. Using promptly downlinked data we find a bright,
variable, uncatalogued X-ray source with an enhanced position: RA, Dec
251.6759, 0.0769 which is equivalent to:
RA(J2000) = 16h 46m 42.21s
Dec(J2000) = +00d 04' 36.8"
with an uncertainty of 3.0 arcseconds (radius, 90% containment). This
location is 122 arcseconds from the BAT onboard position, within the
BAT error circle. This position may be improved as more data are
received; the latest position is available at
http://www.swift.ac.uk/sper.
A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density consistent with the Galactic value of
6.45e+20 cm^-2 (Kalberla et al. 2005).
The initial flux in the 2.5 s image was 3.05e-09 erg cm^-2 s^-1 (0.2-10
keV).
UVOT took a finding chart exposure of 150 seconds with the White
filter starting 86 seconds after the BAT trigger. No credible
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 3-sigma
upper limit at the location of the XRT candidate is 19.3 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 mag. No correction has been made for the expected
extinction corresponding to E(B-V) of 0.16.
Burst Advocate for this burst is T. Sakamoto (Taka.Sakamoto AT nasa.gov).
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)
GCN Circular 8796
Subject
GRB 090111: Enhanced Swift-XRT position
Date
2009-01-12T04:41:17Z (16 years ago)
From
Phil Evans at U of Leicester <pae9@star.le.ac.uk>
P.A. Evans, M.R. Goad, J.P. Osborne and A.P. Beardmore (U. Leicester)
report on behalf of the Swift-XRT team.
Using 1667 s of XRT Photon Counting mode data and 2 UVOT
images for GRB 090111, we find an astrometrically corrected X-ray
position (using the XRT-UVOT alignment and matching UVOT field sources
to the USNO-B1 catalogue): RA, Dec = 251.67557, +0.07728 which is equivalent
to:
RA (J2000): 16h 46m 42.14s
Dec (J2000): +00d 04' 38.2"
with an uncertainty of 1.7 arcsec (radius, 90% confidence).
This position may be improved as more data are received. The latest position
can be viewed at http://www.swift.ac.uk/xrt_positions. Position enhancement is
described by Goad et al. (2007, A&A, 476, 1401
http://www.swift.ac.uk/xrt_positions/Goad.pdf), the current algorithm is an
extension of this method.
This circular was automatically generated, and is an official product of the
Swift-XRT team.
GCN Circular 8797
Subject
GRB 090111: Swift-XRT refined analysis
Date
2009-01-12T12:05:47Z (16 years ago)
From
Raffaella Margutti at U. di Milano Bicocca <raffaella.margutti@brera.inaf.it>
R. Margutti (Univ. Bicocca & INAF-OAB), J. Mao (INAF-OAB),
T. Sakamoto (NASA/UMBC) report on behalf of the Swift XRT team:
We have analysed the first 2 orbits of Swift-XRT data obtained for
GRB 090111 (Sakamoto et al., GCN Circ. 8795), covering 70 s of
Windowed Timing (WT) and 4 ks of Photon Counting (PC) mode data,
respectively, between 77 s and 8 ks after the trigger.
The UVOT-enhanced XRT position was given by Evans et al. in
GCN Circ. 8796.
In the time interval 77-150 s, the light curve can be modelled by a
simple power law with a decay index alpha_1= 5.1 +/- 0.3 (90% confidence)
followed by a rebrightening around 0.5 ks.
After the rebrightnening the light curve decays with a powerlaw index
alpha_2= 3.6 +/- 0.4 and then flattens to alpha_3= 0.4 +/- 0.1
with a t_break of 1200 s.
The spectrum extracted from WT data can be modelled with an
absorbed simple power-law, with Gamma = 5.4 +/- 0.5 and
NH = (5.4 +/- 0.8)x10^21 cm^-2 in excess of the Galactic column in
this direction which is 6.5x10^20 cm^-2 (Kalberla et al. 2005).
The observed (unabsorbed) 0.3 -10 keV
flux over this time interval (77-150 s post-trigger) is
3.8x10^-10 (2.7x10^-8) erg cm^-2 s^-1.
The spectrum extracted from PC data in the time interval 150-8000 s
can be modelled with an absorbed power-law, with Gamma= 3.3 +/- 0.5
and an intrinsic column density of NH = (2.0 +/- 0.8)x10^21 cm^-2.
The observed (unabsorbed) 0.3 -10 keV flux over this time
interval is 3.0x10^-12 (1.2x10^-11) erg cm^-2 s^-1.
Uncertainties are given at 90% confidence.
If the light-curve continues to decay with alpha ~0.4, the count rate 24
hours after the burst is estimated to be 1.3x10^-2 count s^-1, which
corresponds to an observed flux of 4x10^-13 erg cm^-2 s^-1.
The results of the xrt automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00339696.
This is an official product of the Swift-XRT team.
GCN Circular 8799
Subject
GRB 090111: Swift UVOT Upper Limits
Date
2009-01-12T19:11:09Z (16 years ago)
From
Erik Hoversten at Swift/Penn State <hoversten@astro.psu.edu>
E. A. Hoversten (PSU) and T. Sakamoto (NASA/UMBC) report on behalf of
the Swift UVOT team:
The Swift/UVOT began settled observations of the field of
GRB 090111 86s after the BAT trigger (Godet et al., GCN 8795).
We do not detect any source at the enhanced Swift XRT position (Evans
et al. GCN 8796). UVOT magnitude 3-sigma upper limits are reported in
the following table:
Filter T_start T_stop Exp(s) Mag (3-sigma upper limit)
-------------------------------------------------------------
WHITE 86 235 146 > 20.25
WHITE 86 1545 391 > 20.78
v 627 1768 136 > 18.47
b 553 1866 136 > 19.37
u 298 547 245 > 19.56
u 298 1841 608 > 20.03
uvw1 676 1817 136 > 19.22
uvw2 603 1743 136 > 19.52
The quoted upper limits have not been corrected for the expected
Galactic extinction along the line of sight of E_(B-V) = 0.16 mag.
All photometry is on the UVOT photometric system described in Poole et
al. (2008, MNRAS, 383, 627).
GCN Circular 8800
Subject
GRB 090111, Swift-BAT refined analysis
Date
2009-01-12T20:52:55Z (16 years ago)
From
Hans Krimm at NASA-GSFC <hans.krimm@nasa.gov>
M. Stamatikos (GSFC/ORAU), S. D. Barthelmy (GSFC), W. H. Baumgartner
(GSFC/UMBC),
J. R. Cummings (GSFC/UMBC), E. E. Fenimore (LANL), N. Gehrels (GSFC),
H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC/UMD), K. McLean (GSFC/UMD),
D. M. Palmer (LANL), A. M. Parsons (GSFC), T. Sakamoto (GSFC/UMBC),
G. Sato (ISAS), J. Tueller (GSFC), T. N. Ukwatta (GWU)
(i.e. the Swift-BAT team):
Using the data set from T-239 to T+963 sec from the recent telemetry
downlink,
we report further analysis of BAT GRB 090111 (trigger #339696)
(Sakamoto et al., GCN Circ. 8795). The BAT ground-calculated position is
RA, Dec = 251.656, 0.067 deg which is
RA(J2000) = 16h 46m 37.4s
Dec(J2000) = +00d 04' 01.5"
with an uncertainty of 1.4 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 82%.
The mask-weighted light curve shows two peaks of roughly equal intensity.
The first lasts from T-3 sec to T+9 sec and the second from T+10 to T+26
seconds.
T90 (15-350 keV) is 24.8 +- 2.7 sec (estimated error including
systematics).
The time-averaged spectrum from T-2.9 to T+25.6 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
2.37 +- 0.17. The fluence in the 15-150 keV band is 6.2 +- 0.6 x 10-7
erg/cm2.
The 1-sec peak photon flux measured from T+10.70 sec in the 15-150 keV band
is 0.9 +- 0.2 ph/cm2/sec. All the quoted errors are at the 90% confidence
level.
The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/339696/BA/
GCN Circular 11385
Subject
GRB 090111, the review of the sky area in plate archives (1976-1996)
Date
2010-10-28T11:47:27Z (15 years ago)
From
Valentyna Golovnya at Main Astro Obs,Kyiv <golov_v@ukr.ne>
GRB 090111, the review of the sky area in plate archives (1976-1996)
V.V. Golovnya, L.N. Kizyun (Main Astronomical Observatory, Kyiv)
report:
We have undertaken the review of the sky area of GRB 090111
(Evans et al., GCN 8796) on astronegatives, collected in Ukrainian NAS
Main
astronomical observatory plate archive (1976-1996)[1,2,3]. All the
plates
with the possible object appearance are digitized using Microtek
ScanMaker
9800XL TMA flatbed scanner and have been placed into Golosiiv Plate
Archive
database DBGPA with open access to them.
The list of plates is given in the table:
YYYYMMDD UT GUA_ID Exp. LimMag Star
19790419 22:37:48 GUA040C001160B 5 14.4 USNO A2 0900-08951386
19790503 23:54:51 GUA040C001168B 6 14.4 USNO A2 0900-08951386
19790503 23:54:51 GUA040D001169 6 14.65 USNO A2 0900-08945162
19800515 23:06:42 GUA040D001747 20 14.4 USNO A2 0900-08951386
19800515 23:06:34 GUA040C001746B 20 14.65 USNO A2 0900-08945162
19810521 22:48:36 GUA040D001952 3 11.63 TYC 384-480-1
19820515 22:46:59 GUA040C000082A 27 16.35 USNO A2 0900-08949620
19910613 21:25:17 GUA040C001800A 22.5 17.3 USNO A2 0900-08949717
GUA ID - Double Wide-angle Astrograph (D/F=40/2000, M=103"/mm)
of the Ukrainian NAS Main astronomical observatory in Kyiv
(Marsden's number - 83) the plate number[4].
Exp. - Duration of the maximum exposures (minutes).
LimMag - Limited mag, derived in the 15 minutes area around the
location
given in Evans et al., GCN 8796
Star - Comparison star.
The preview images can be found
http://gua.db.ukr-vo.org/img/grb/090111/index.html.
The images with full resolution are available via e-mail on demand.
References:
1. L.Pakulyak , N.Kharchenko, E.Izhakevich, V.Golovnya, V.Kisljuk,
V.Andruk. Data base of photographic observations of celestial bodies
of
Golosiiv observatory. Baltic Astron. 6, 1997.
2. L.Pakulyak, N.Kharchenko, E.Izhakevich, V.Golovnya, V.Andruk,
V.Kisljuk. Data base of photographic observations of celestial bodies
of Golosiiv observatory in Kiev. Newsletters of IAU WG "Wide-field
imaging" No 9, 1997
3. V.Kislyuk, A.Yatsenko, G.Ivanov, L.Pakuliak, T.Sergeeva. The
FON Astrographic catalogue (FONAC): version1.0. Proc. of Journees
1999 and IX Lohrmann-Kolloquium "Motion of celestial bodies,
astromerty and astronomical reference frames", Drezden, September
13-15,1999
4.L.Pakulyak DATABASE of GOLOSIIV PLATE ARCHIVE (DBGPA V2.0),
http://gua.db.ukr-vo.org/