GRB 090205
GCN Circular 8884
Subject
GRB 090205: Swift detection of a burst
Date
2009-02-05T23:17:10Z (16 years ago)
From
Scott Barthelmy at NASA/GSFC <scott@lheamail.gsfc.nasa.gov>
M. Perri (ASDC), S. D. Barthelmy (GSFC),
W. H. Baumgartner (GSFC/UMBC), D. N. Burrows (PSU),
N. Gehrels (NASA/GSFC), O. Godet (U Leicester), C. Gronwall (PSU),
S. T. Holland (CRESST/USRA/GSFC), E. A. Hoversten (PSU),
W.B Landsman (GSFC), C. B. Markwardt (CRESST/GSFC/UMD),
F. E. Marshall (NASA/GSFC), D. M. Palmer (LANL),
M. Stamatikos (NASA/ORAU), G. Stratta (ASDC), M. C. Stroh (PSU) and
L. Vetere (PSU) report on behalf of the Swift Team:
At 23:03:14 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 090205 (trigger=342121). Swift slewed immediately to the burst.
The BAT on-board calculated location is
RA, Dec 220.925, -27.864 which is
RA(J2000) = 14h 43m 42s
Dec(J2000) = -27d 51' 48"
with an uncertainty of 3 arcmin (radius, 90% containment, including
systematic uncertainty). The BAT light curve shows a single peak
with a duration of about 10 sec. The peak count rate
was ~900 counts/sec (15-350 keV), at ~1 sec after the trigger.
The XRT began observing the field at 23:04:42.4 UT, 87.6 seconds after
the BAT trigger. Using promptly downlinked data we find an uncatalogued
X-ray source located at RA, Dec 220.91150, -27.85298 which is
equivalent to:
RA(J2000) = 14h 43m 38.76s
Dec(J2000) = -27d 51' 10.7"
with an uncertainty of 3.8 arcseconds (radius, 90% containment). This
location is 58 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
7.72e+20 cm^-2 (Kalberla et al. 2005).
UVOT took a finding chart exposure of 150 seconds with the White
filter starting 92 seconds after the BAT trigger. No credible
afterglow candidate has been found in the initial data products.
The 8'x8' region for the list of sources generated on-board covers
100% of the BAT error circle and 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
0.12.
Burst Advocate for this burst is M. Perri (perri AT asdc.asi.it).
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 8885
Subject
GRB 090205: Enhanced Swift-XRT position
Date
2009-02-06T02:40:31Z (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 944 s of XRT Photon Counting mode data and 1 UVOT
images for GRB 090205, 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 = 220.91119, -27.85267 which is equivalent
to:
RA (J2000): 14h 43m 38.69s
Dec (J2000): -27d 51' 09.6"
with an uncertainty of 1.8 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 8886
Subject
GRB 090205: Swift-BAT refined analysis
Date
2009-02-06T03:30:35Z (16 years ago)
From
Scott Barthelmy at NASA/GSFC <scott@lheamail.gsfc.nasa.gov>
GRB 090205: Swift-BAT refined analysis
J. R. Cummings (GSFC/UMBC), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),
E. E. Fenimore (LANL), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA),
C. B. Markwardt (GSFC/UMD), D. M. Palmer (LANL), M. Perri (ASDC),
T. Sakamoto (GSFC/UMBC), G. Sato (ISAS), M. Stamatikos (GSFC/ORAU),
J. Tueller (GSFC), T. N. Ukwatta (GWU)
(i.e. the Swift-BAT team):
Using the data set from T-239 to T+455 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 090205 (trigger #342121)
(Perri, et al., GCN Circ. 8884). The BAT ground-calculated position is
RA, Dec = 220.917, -27.848 deg which is
RA(J2000) = 14h 43m 40.0s
Dec(J2000) = -27d 50' 51.4"
with an uncertainty of 2.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 100%.
The mask-weighted light curve shows a single peak starting at ~T-5 sec,
peaking at ~T+3 sec, and returning to background at ~T+100 sec.
T90 (15-350 keV) is 8.8 +- 1.8 sec (estimated error including systematics).
The time-averaged spectrum from T-2.9 to T+6.6 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
2.15 +- 0.23. The fluence in the 15-150 keV band is 1.9 +- 0.3 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T+4.09 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.
The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/342121/BA/
GCN Circular 8887
Subject
GRB 090205: VLT candidate afterglow
Date
2009-02-06T07:20:57Z (16 years ago)
From
Paolo D'Avanzo at INAF-OAB <paolo.davanzo@brera.inaf.it>
P. D'Avanzo, C. C. Thoene, D. Fugazza (INAF-OAB), V. D'Elia, S.
Piranomonte (INAF-OAR), R. Salvaterra, S. Covino, S. Campana (INAF-OAB),
G. Chincarini (Univ. Bicocca) report, on behalf of the MISTICI
collaboration:
We observed the field of GRB 090205 (Perri et al., GCN 8884) with the
ESO-VLT in imaging mode starting about 7.1 hours after the burst.
Observations were carried out in R and I-band with the FORS1 camera.
Inside the enhanced XRT error circle (Evans et al. GCN 8885) we find a
source at the following coordinates (J2000):
R.A. = 14:43:38.65
Dec. = -27:51:10.7
+/- 0.4"
Preliminary photometry of this candidate afterglow gives R ~ 22.0 .
We acknowledge the VLT staff for their support, in particular G. James
and J. Smoker.
GCN Circular 8888
Subject
GRB 090205: GROND observations and photometric redshift estimate
Date
2009-02-06T07:26:53Z (16 years ago)
From
Thomas Kruehler at MPE/MPI <kruehler@mpe.mpg.de>
T. Kruehler and J.Greiner (both MPE Garching) report on behalf of the
GROND team:
We observed the field of GRB 090205 (Swift trigger 342121, M. Perri et
al.,GCN #8884) simultaneously in g'r'i'z'JHK with GROND mounted at the
2.2m ESO/MPI telescope at La Silla Observatory (Chile).
Observations started on 03 Feb. 2009 at 05:25 UT, 6.33 h after the burst.
The object reported by D'Avanzo et al. (GCN #8887) is very well detected
in the i' band and redder, marginally in r' and not in g'. A preliminary
i' band magnitude is 20.7 +- 0.2 roughly 7 hours after the burst.
Interpreting the large r'-i' color and the g' band non detection as
Lyman-alpha absorption in the GRB host, we derive a photometric redshift
of 4.7 +- 0.3. This redshift estimate has been obtained using hyperZ
(Bolzonella et al. 2000). We caution that this is based on a preliminary
calibration.
No statement about variability can be made at this point.
[GCN OPS NOTE(06feb09): Per author's request, date and time in the sentence
in the second paragraph were changed from "03 Feb" to "06 Feb"
and from "05:25" to "05:23".]
GCN Circular 8889
Subject
GRB 090205: VLT spectroscopic redshift
Date
2009-02-06T08:57:35Z (16 years ago)
From
Paolo D'Avanzo at INAF-OAB <paolo.davanzo@brera.inaf.it>
C. C. Thoene, D. Fugazza, P. D'Avanzo (INAF-OAB), V. D'Elia, S.
Piranomonte (INAF-OAR), R. Salvaterra, S. Covino, S. Campana (INAF-OAB),
G. Chincarini (Univ. Bicocca) report, on behalf of the MISTICI
collaboration:
We observed the optical afterglow of GRB 090205 (D'Avanzo et al. GCN
8887; Kruehler & Greiner GCN 8888) with the ESO VLT about 9.0 hours
after the burst with the FORS1 camera in spectroscopic mode. We took a
20 min spectrum covering the range 4000-9000 Angstrom (based on a
preliminary wavelength calibration) with a resolution of R=440.
We detect a broad absorption feature around lambda_obs = 6800 Angstrom.
Interpreting this feature as Ly-alpha absorption the inferred redshift
is z = 4.6 in agreement with the photometric redshift reported by
Kruehler & Greiner (GCN 8888).
We acknowledge excellent support from the ESO staff, in particular G.
James and J. Smoker.
GCN Circular 8890
Subject
GRB 090205: Swift burst of interest
Date
2009-02-06T14:46:05Z (16 years ago)
From
Neil Gehrels at GSFC <cornelis.a.gehrels@nasa.gov>
N. Gehrels (GSFC) & M. Perri (ASDC) report on behalf of the Swift team
Based on its high redshift, relatively bright optical afterglow and
variable X-ray afterglow, the Swift team declares GRB 090205
to be a burst of interest to be followed by Swift as long as
detectable. We encourage ground-based follow-ups. Please
post your results / plans or send us informal information to
help with observation planning.
GCN Circular 8891
Subject
GRB 090205: Swift-XRT refined analysis
Date
2009-02-06T15:58:50Z (16 years ago)
From
Matteo Perri at ISAC/ASDC <perri@asdc.asi.it>
M. Perri and G. Stratta (ASDC) report on behalf of the Swift XRT team:
We have analyzed the first 13.5 ks of Swift-XRT data of the BAT GRB
090205 (Perri et al., GCN Circ. 8884). The data, starting at 2009-02-05
23:04:55 UT and ending at 2009-02-06 09:10:33 UT, is all taken in
Photon Counting (PC) mode.
The best XRT position is the UVOT-enhanced position reported by
Evans et al. (GCN Circ. 8885).
In the time interval T+94s-T+580 s the X-ray light curve can be modeled by
a simple power law with a decay index alpha_1= 1.4 � 0.3 (90% confidence)
followed by a re-brightening around T+1 ks. After the re-brightnening,
from T+5 ks up to T+30 ks, the light curve decays with a power law
index alpha_2= 0.9 � 0.2.
The X-ray spectrum is well fit by an absorbed power-law model
with a photon index of 2.0 (+/-0.2) and a column density consistent
with the Galactic one in the direction of the source (7.7e20 cm**-2,
Kalberla et al. 2005). The estimated 3-sigma (2-sigma) upper limit on the
intrinsic column density at z=4.6 (Thoene et al., GCN Circ. 8889) is
4.1e22cm**-2 (2.8e22cm**-2).
Assuming the X-ray emission continues to decline at the same rate, we
predict a 0.3-10 keV XRT count rate of 6e-3 count/s at T+24hr, which
corresponds to an observed 0.3-10 keV flux of ~2e-13 erg/cm**2/s.
This circular is an official product of the Swift-XRT Team.
GCN Circular 8892
Subject
GRB 090205: VLT refined redshift
Date
2009-02-06T16:23:14Z (16 years ago)
From
Paolo D'Avanzo at INAF-OAB <paolo.davanzo@brera.inaf.it>
D. Fugazza, C. C. Thoene (INAF-OAB), V. D'Elia (INAF-OAR), P. D'Avanzo
(INAF-OAB), S. Piranomonte (INAF-OAR), R. Salvaterra, S. Covino, S.
Campana (INAF-OAB), G. Chincarini (Univ. Bicocca) report, on behalf of
the MISTICI collaboration:
We performed further analysis of our VLT spectrum of the optical
afterglow of GRB 090205 (D'Avanzo et al. GCN 8887; Kruehler & Greiner,
GCN 8888; Thoene et al., GCN 8889).
We clearly detect the following absorption features: Ly_alpha (1215.67),
SiII (1260.66), SiII (1303.27), CII (1334.53), SiIV (1393.76, 1402.77)
doublet, SiII (1526.71) and CIV (1548.20,1550.77) doublet at a redshift
of z = 4.6497 � 0.0025 consistent with previous claims (Kruehler &
Greiner, GCN 8888; Thoene et al., GCN 8889).
GCN Circular 8893
Subject
GRB 090205: Swift/UVOT Upper Limits
Date
2009-02-06T16:54:59Z (16 years ago)
From
Wayne Landsman at GSFC/SSAI <wayne.b.landsman@nasa.gov>
W. Landsman (NASA/GSFC) and M. Perri (ASDC) report on behalf of the
Swift UVOT team
The Swift/UVOT began settled observations of the field of GRB 090205 92s
after the BAT trigger (Perri et al., GCN 8884). We do not detect any
source at the enhanced Swift XRT position (Evans et al. GCN 8885) or at
the VLT optical candidate position (D'Avanzo et al. GCN 8887). The
UVOT non-detections are consistent with the spectroscopic redshift of
4.6 reported by Thoene et al. (GCN 8889). Our 3-sigma upper limits
are reported below.
Filter T_start T_stop Exp(s) Mag (3-sigma upper limit)
-------------------------------------------------------------
white 92 242 148 > 21.1
white 92 7633 824 > 21.9
v 580 12829 1234 > 20.7
b 506 34930 2073 > 21.7
u 250 500 246 > 20.5
u 298 18581 1660 > 21.4
uvw1 629 17668 1415 > 21.4
uvm2 604 23148 1882 > 21.4
uvw2 555 11915 1322 > 21.5
The quoted upper limits have not been corrected for the expected
Galactic extinction along the line of sight of E_(B-V) = 0.12 mag. All
photometry is on the UVOT photometric system described in Poole et al.
(2008, MNRAS, 383, 627).
GCN Circular 8895
Subject
GRB 090205: VLT optical decay
Date
2009-02-07T09:35:05Z (16 years ago)
From
Paolo D'Avanzo at INAF-OAB <paolo.davanzo@brera.inaf.it>
P. D'Avanzo, D. Fugazza (INAF-OAB), V. D'Elia (INAF-OAR), R. Salvaterra,
C. C. Thoene (INAF-OAB), S. Piranomonte (INAF-OAR), S. Covino, S.
Campana (INAF-OAB), G. Chincarini (Univ. Bicocca) report, on behalf of
the MISTICI collaboration:
We continued monitoring GRB 090205 (Perri et al., GCN 8884) with the
ESO-VLT in imaging mode. Observations were carried out in R-band with
the FORS1 camera about 1.35 days after the burst.
Preliminary analysis of a first set of images (total exposure: 12 min)
reveals that the optical afterglow (D'Avanzo et al. GCN 8887; Kruehler &
Greiner GCN 8888) is still detected and that it faded by about 3 mags
with respect to our previous epoch of VLT observations (D'Avanzo et al.
GCN 8887). Assuming a power-law decy, the inferred decay index between
this two epochs is alpha ~ 1.8, steeper than what measured in the X-rays
at earlier epochs (Perri & Stratta, GCN 8891). Further optical
observations are ongoing.
We acknowledge the VLT staff for their support, in particular G. James
and L. Schmidtobreick.
GCN Circular 8896
Subject
VLA radio upper limit on GRB 090205
Date
2009-02-07T14:57:15Z (16 years ago)
From
Poonam Chandra at U Virginia/NRAO <pc8s@virginia.edu>
Poonam Chandra (RMC) and Dale A. Frail (NRAO) report on
behalf of the Caltech-NRAO-Carnegie GRB Collaboration:
"We used the Very Large Array to observe the field of view toward
GRB 090205 (GCN 8884) at a frequency of 8.46 GHz on 2009 Jan 07.50
UT. The GRB radio afterglow is undetected at 3-sigma level. The
flux density at the VLT afterglow position (GCB 8887) is 21 � 47 uJy.
The National Radio Astronomy Observatory is a facility of the National
Science Foundation operated under cooperative agreement by Associated
Universities, Inc."
GCN Circular 8976
Subject
GRB 090205: Zadko Telescope late-time observations
Date
2009-03-11T03:45:11Z (16 years ago)
From
David Coward at U of Western Aus. <coward@physics.uwa.edu.au>
SUBJECT: GRB 090205: Zadko Telescope late-time observations
From: D.M. Coward at UWA
T.P. Vaalsta reports on behalf of the UWA Zadko Telescope Team:
D.M. Coward, T.P. Vaalsta, J. Zadko, A. Imerito, D. Blair, P. Luckas,
S. Gordon, K. Frost, A. Fletcher (U. of Western Australia)
M. Todd, M. Zadnik (Curtin University)
M. Boer, A. Klotz (TAROT)
The Zadko Telescope team observed the field of GRB 090205
following the report by N. Gehrels and M. Perri (GCN 8525, 09/02/06
14:46:05 GMT). Observations started at 09/02/06 16:38:29 GMT using an
iKon DW436BV CAMERA without filters mounted on the F/4 1.0m Zadko
Telescope about 17.6 hours after the initial burst trigger (GCN 8884).
The GRB field was imaged for a total of 4460s until dawn. In a 1100s
stacked image, a candidate OA with 23.2(3) white magnitude was
observed at the enhanced XRT position (GCN 8885). The OA magnitude
was estimated differentially using nearby nearby USNO-B1 stars as
references.
The same field was imaged 2 weeks later and the candidate OA was not
detected.
The UWA Zadko Telescope is currently being commissioned.
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