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GRB 060211A, GRB 060211

GCN Circular 5204

Subject
GRB 060211A : WIDGET simultaneous optical observations
Date
2006-06-03T12:40:27Z (20 years ago)
From
Toru Tamagawa at RIKEN <tamagawa@riken.jp>
Y. Urata (Saitama-U), M. Kuwahara (TUS/RIKEN), M. Tashiro, K. Abe,
K. Onda, N. Kodaka, K. Masuno (Saitama-U), F. Usui (ISAS/JAXA),
T. Tamagawa (RIKEN) report: 

"WIDGET has continuously monitored the entire error region of the GRB
060211A (Hurkett et al. GCN 4736, 4740) with repeat of unfiltered
5-second exposures during the night of 11th February. The 1-sigma
limiting magnitude of images taken between 792 seconds before and 321
seconds after the burst was around V=10.8 magnitude. The magnitude was
derived by the Tycho-2 catalog. There was no significant emission from
the X-ray afterglow position up to the limiting magnitudes." 

This message maybe cited.

GCN Circular 4927

Subject
GRB 060211A: optical observation
Date
2006-03-27T12:11:35Z (20 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
D. Sharapov (MAO, and NOT, La Palma),  M. Ibrahimov, (MAO), A. Pozanenko
(IKI) and V. Rumyantsev (CrAO) on behalf of larger GRB follow up
collaboration report:

We observed the refined XRT error box reported by Hurkett et al. (GCN 4740)
of  GRB 060211A (Hurkett et al. GCN 4736; Krimm et al. GCN 4757) with 1.5m
telescope of  Maidanak Astronomical Observatory in R-band on Feb. 11 (UT)
15:02 - 15:22. The limiting  magnitude is based on USNO B1.0:

Mid. time,   Exp.,   Limit,  Seeing
(UT)         (s)

Feb.11.640   1860    22.0    ~1.5"

The extended object   in the FOV with coordinates RA(J2000)= 03:53:31 (+/-
10 arcsec)  Dec(J2000)= +21:28:58 (+/- 10 arcsec)  with R~21.5 is the
asteroid 16306 moving  toward N-E.

The combined image can be found in
http://grb.rssi.ru/GRB060211/GRB060211_AZT22R.jpg

GCN Circular 4760

Subject
GRB 060211a: WIRO NIR Observations
Date
2006-02-14T03:32:59Z (20 years ago)
From
Jay Norris at NASA-GSFC/LHEA <jnorris@lheapop.gsfc.nasa.gov>
J. Norris, A. Kutyrev (NASA/GSFC), R. Ganguly, R. Canterna,
and M. Pierce (U. Wyoming) report:

We observed the refined XRT error box reported by Hurkett et al. (GCN 4740)
for the very long burst, GRB 060211a (Swift trigger #181126; Hurkett et al.
GCN 4736; Krimm et al. GCN 4757) with the 2.3-meter WIRO telescope.

Observations commenced at 2006/02/12 02:44 UT (17 hrs after the burst)
and continued until 03:24 UT.  We obtained thirty-six 50-s integrations
in the J band under poor seeing conditions.  In the stacked image,
no source was detected within the XRT error circle to a limit of
J = 19.1  (3-sigma upper limit).

GCN Circular 4757

Subject
GRB 060211A: Further refined analysis of the Swift burst
Date
2006-02-13T18:39:23Z (20 years ago)
From
Hans Krimm at NASA-GSFC <krimm@milkyway.gsfc.nasa.gov>
H. Krimm (GSFC/USRA), L. Barbier (GSFC), S. Barthelmy (GSFC),
J. Cummings (GSFC/ORAU), E. Fenimore (LANL), N. Gehrels (GSFC),
D. Hullinger (GSFC/UMD), C. Hurkett (U Leicester),
C. Markwardt (GSFC/UMD), D. Palmer (LANL), 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-300 to T+303 sec from a recent telemetry
downlink, we report further analysis of the results from BAT GRB 060211A
(trigger #181126) (Hurkett, et al., GCN 4736, Sato, et all, GCN 4751).
The BAT ground-calculated position is  RA,Dec = 58.380, 21.489  deg
{3h 53m 31.1s, 21d 29' 20.0"} (J2000) +- 1.5 arcmin, (radius,
sys+stat, 90% containment).  The partial coding was 100%.

The mask-weighted lightcurve shows that this was a very long burst.
There was a weak, soft precursor starting at T-180 secs and lasting,
in the lowest energy band, until T-90 secs.  There is another episode
of weak emission from T-10 to T+50, and then two prominent peaks
from T+50 to T+100 and from T+130 to T+180 secs.  The first of
the main peaks is harder than the second.  There is no significant
emission beyond T+190 secs.  T90 (15-350 keV) is (126 +- 5) sec
(estimated error including systematics).

The time-averaged spectrum from T+47.8 to T+191.0 is best fit by
a power law with an exponential cutoff.  This fit gives a photon
index of 0.85 +- 0.53, and Epeak of 58.3 +- 13.2 keV (chi squared 59
for 56 d.o.f.).  For this model the total fluence in the 15-150 keV band
is (1.5 +- 0.1) x 10^-06 erg/cm2 and the 1-sec peak flux measured
from T+145.58 sec in the 15-150 keV band is (0.4 +- 0.1) ph/cm2/sec.
A fit to a simple power law gives a photon index of 1.76 +- 0.11
(chi squared 70 for 57 d.o.f.).  All the quoted errors are at the 90%
confidence level.

GCN Circular 4751

Subject
GRB 060211A: Partial refined analysis on the Swift-BAT burst
Date
2006-02-12T17:06:41Z (20 years ago)
From
Scott Barthelmy at NASA/GSFC <Scott@lheamail.gsfc.nasa.gov>
G. Sato (ISAS), L. Barbier (GSFC), S. Barthelmy (GSFC),
J. Cummings (GSFC/ORAU), E. Fenimore (LANL), N. Gehrels (GSFC),
D. Hullinger (GSFC/UMD), C. Hurkett (U Leicester), H. Krimm (GSFC/USRA),
C. Markwardt (GSFC/UMD), D. Palmer (LANL), A. Parsons (GSFC),
T. Sakamoto (GSFC/ORAU), J. Tueller (GSFC)
on behalf of the Swift-BAT team:

Using a paritally downloaded data set from T-60 to T+123 sec
from a recent telemetry downlink, we report further analysis
of BAT GRB 060211A (trigger #181126) (Hurkett, et al., GCN 4736).
The BAT ground-calculated position is RA,Dec = 58.361,+21.485 deg
{3h 53m 26.6s,+21d 29' 4.4"} (J2000) +- 1.5 arcmin, (radius, sys+stat,
90% containment).  The partial coding was 100%.
 
Using data from T-60 to +123, the lightcurve shows some very weak emission
starting at T_zero out to T+50, then the bulk of the emission is 
from T+50 to T+100 with weak emission extending out to T+123
where our downloaded data set currently ends.  T90 (15-350 keV) is 43 +- 10 sec
(estimated error including systematics).
 
The time-averaged spectrum from T+47.8 to T+97.1 is best fit by a power law
with an exponential cutoff.  This fit gives a photon index 0.40 +- 0.64, 
and an Epeak of 94 +- 49 keV (chi squared 42 for 56 d.o.f.).  
For this model the total fluence in the 15-150 keV band is
8.2 +- 0.8 x 10^-07 erg/cm2 and the 1-sec peak flux measured
from T+53.94 sec in the 15-150 keV band is 0.3 +- 0.1 ph/cm2/sec.  
A fit to a simple power law gives a photon index of 1.30 +- 0.14
(chi squared 49 for 57 d.o.f.).  All the quoted errors are at the 90%
confidence level.

GCN Circular 4740

Subject
GRB 060211A: Swift XRT Team Refined Analysis
Date
2006-02-11T16:58:32Z (20 years ago)
From
Cheryl Pauline Hurkett at Leicester U <cph9@star.le.ac.uk>
C. P. Hurkett, K. Page, E. Rol, J. Osborne, O. Godet and A. Beardmore (U
Leicester) report on behalf of the Swift XRT team:

We have analysed the Swift XRT data from the first orbit observation of
GRB 060211A (Hurkett et al. GCN 4736), with a total Windowed Timing (WT)
mode exposure of 195 seconds and Photon Counting (PC) mode exposure of
1040 seconds. The refined XRT position is:

RA(J2000) = 03 53 32.8
Dec(J2000) = +21 29 21.0

This position is 3.9 arcseconds from the XRT position given in GCN
4736.  We estimate an uncertainty of 3.7 arcseconds radius (90%
containment).

The 0.3-10 keV light curve in WT and PC mode starts 185 seconds from the
BAT trigger. The lightcurve (after only one orbit) appears to exhibit a
broken powerlaw behaviour, where both decay indices are steep. The indices
are: alpha_1 = 4.14 +/- 0.11, which at 475 seconds (+48/-32) changes to a
slower decay of alpha_2 = 2.26 (+0.26/-0.32).

A preliminary spectral fit to the WT data gives a power law photon
index of 1.94 +/- 0.07 in the 0.3-10 keV band, where Galactic
absorption is assumed to be 1.25e21 cm^-2. An excess absorption
component is noted at (7+/-2)e20 cm^-2. In the time range of 185-380
seconds after trigger, the estimated unabsorbed 0.3-10 keV flux is
1.19e-9 ergs/cm2/s. The observed 0.3-10.0 keV flux is 8.54e-10
erg/cm2/s.

Because of the Malindi Gap, only one orbit of data has been analysed
so far. We cannot accurately estimate the flux at T+24 hr yet.

This circular is an official product of the Swift XRT Team.

GCN Circular 4738

Subject
GRB060211: Faulkes North observation
Date
2006-02-11T11:21:08Z (20 years ago)
From
Andreja Gomboc at ARI,Ljubljana,Slovenia/Swift <andreja.gomboc@fmf.uni-lj.si>
A. Gomboc, C. Guidorzi, I. A. Steele, S. Kobayashi, C.G. Mundell, A.
Monfardini, A. Melandri,
C.J. Mottram, R.J. Smith, D. Bersier,
D. Carter, M.F. Bode (Liverpool JMU), P. O'Brien, E. Rol, N. Bannister
(U. of Leicester) report:

"The 2-m Faulkes Telescope North robotically followed up GRB060211
(SWIFT trigger 181126, Hurkett et al. GCN 4736) starting 5.4 min after
the GRB trigger time.
Within the XRT position, we do not find an optical counterpart to a 
limiting magnitude of R~18.5 in 3x10s co-added images. In addition, we 
find no obvious candidates in a 4.6' x 4.6' region centered on the 
BAT position, to the same limiting magnitude.
Limiting magnitude has been derived with reference to USNOB1."

GCN Circular 4737

Subject
GRB 060211: ROTSE-III Optical Limits
Date
2006-02-11T10:43:25Z (20 years ago)
From
Wiphu Rujopakarn at U Michigan/ROTSE <wiphu@umich.edu>
W. Rujopakarn (U Mich), E.S. Rykoff (U Mich), B. E. Schaefer (Louisiana 
State), F. Yuan (U Mich), S.A. Yost (U Mich), report on behalf of the 
ROTSE collaboration:

ROTSE-IIIa, located at Siding Spring Observatory, Australia, responded 
to GRB 060211 (Hurkett et al., GCN 4736), producing images beginning 
6.2 s after the GCN notice time. An automated response took the first 
image at 09:41:38.2 UT, 147.2 s after the burst, under twilight 
conditions. We took 10 5-sec, and 100 20-sec exposures. These 
unfiltered images are calibrated relative to USNO A2.0 (R).

Comparison to the DSS (second epoch) reveals no new sources within the 
3-sigma error circle, for both single images and coadding into sets of 
10. Individual images have limiting magnitudes ranging from 14.0-16.2; 
we set the following specific limits.

start UT       end UT      t_exp(s)   mlim   t_start-tGRB(s)  Coadd?
--------------------------------------------------------------------
09:41:38.2   09:41:43.2         5     14.3          147.2       N
09:41:38.2   09:43:51.7       133     15.7          147.2       Y
09:44:00.9   09:48:44.2       283     16.1          289.9       Y

GCN Circular 4736

Subject
GRB 060211: Swift detection of a long burst
Date
2006-02-11T10:13:41Z (20 years ago)
From
Hans Krimm at NASA-GSFC <krimm@milkyway.gsfc.nasa.gov>
C. Hurkett (U Leicester), A. Beardmore (U. Leicester), O. Godet (U. Leicester),
J. A. Kennea (PSU), H. Krimm (GSFC/USRA), F. Marshall (GSFC),
J. Osborne (U. Leicester), D. Palmer (LANL), A. Parsons (GSFC)
on behalf of the Swift Team:

At 09:39:11 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 060211 (trigger=181126).   The BAT on-board calculated
location is RA,Dec 58.402d, +21.486d {03h 53m 36s, +21d 29' 09"} (J2000)
with an uncertainty of 3 arcmin (radius, 90% containment, including
systematic uncertainty).  Since this was a 128 second image trigger,
we cannot determine the nature of the light curve from the TDRSS light curve.
We will be able to comment on the time structure when we receive the
full data set in a few hours.  The Swift spacecraft slewed promptly onto the
BAT position.

The XRT began observing the field at 09:42:07 UT, 177 seconds after the
BAT trigger. XRT found a bright, fading, uncatalogued X-ray source
located at RA(J2000) = 03h 53m 32.5s, Dec(J2000) = +21d 29' 19.3", with
an estimated uncertainty of 5.0 arcseconds (90% confidence radius).
This location is 55 arcseconds from the BAT on-board position, within
the BAT error circle. The initial flux in the 2.5s image was
6.7e-09 erg/cm2/s (0.2-10 keV).

UVOT took a finding chart exposure of 200 seconds with the V filter starting
183 seconds 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 18.0 mag. No
correction has been made for the expected extinction of about 0.6 magnitudes.

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