GRB 061202

T. Sakamoto (NASA/ORAU), S. D. Barthelmy (GSFC),
W. B. Landsman (NASA/GSFC), K. M. McLean (LANL/UTD), C. Pagani (PSU),
D. M. Palmer (LANL), A. M. Parsons (GSFC), M. Perri (ASDC),
G. Stratta (ASDC) and L. Vetere (PSU) report on behalf of the Swift
Team:

At 08:11:44 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 061202 (trigger=241963).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is RA, Dec 105.642, -74.665 which is 
   RA(J2000)  =  07h 02m 34s
   Dec(J2000) = -74d 39' 53"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve shows a weak peak with
a duration of about 10 sec.  The peak count rate
was ~400 counts/sec (15-350 keV), at ~2 sec after the trigger.  We note
that during the slew there is a large increase in the count rate (T+70 to
T+100 sec) which may be due to the GRB or it may be due to a source
passing through the FOV during the slew. 

The XRT began observing the field at 08:13:43 UT, 119 seconds after
the BAT trigger. XRT found a fading X-ray source located at RA(J2000)
= 07h 02m 06.5s, Dec(J2000) = -74d 41' 55.9", with an estimated
uncertainty of 4.1 arcseconds (90% confidence radius). This is a
ground calculated position based on prompt downlinked data. This
location is 165 arcseconds from the BAT on-board position, within the
BAT error circle. The initial flux in the 2.5s image was 3.6e-09
erg/cm2/s (0.2-10 keV). 

UVOT took a finding chart exposure of 100 seconds with the White (160-650 nm)
filter starting 128 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 18.5 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
0.15.

T. Sakamoto (GSFC/ORAU), L. Barbier (GSFC), S. D. Barthelmy (GSFC),
J. Cummings (GSFC/UMBC), E. Fenimore (LANL), N. Gehrels (GSFC),
D. Hullinger (BYU-Idaho), H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD),
D. Palmer (LANL), A. Parsons (GSFC), G. Sato (GSFC/ISAS),
M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC)
on behalf of the Swift-BAT team:
 
Using the data set from T-239 to T+962 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 061202 (trigger #241963)
(Sakamoto, et al., GCN Circ. 5886
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 ).  The BAT ground-calculated position
is RA, Dec = 105.180, -74.587 deg which is 
   RA(J2000)  =  07h 00m 43.2s 
   Dec(J2000) = -74d 35' 12.5" 
with an uncertainty of 5.8 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 76%.
 
The mask-weighted lightcurve shows that it started with low-level emission
at ~T-95 sec, then BAT triggered on a small peak at T+0 sec which returned
to instrumental background level at ~T+20 sec.  Then some low level emission
starting at ~T+45 sec, then a much larger FRED peak started at ~T+70 sec,
peaking at T+75 sec, and ending at T+200 sec.  T90 (15-350 keV) is 91 +- 5 sec
(estimated error including systematics).
 
The time-averaged spectrum from T-0.8 to T+147.4 is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.63 +- 0.07.  The fluence in the 15-150 keV band is 3.5 +- 0.1 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+75.04 sec in the 15-150 keV band
is 2.6 +- 0.2 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level.

F.E. Marshall (NASA/GSFC) reports on behalf of the Swift/UVOT team:
 
The Swift/UVOT began its first finding chart exposure of the field of  
GRB 061202 129 seconds after the BAT trigger (Sakamoto et al., GCN Circ. 5886
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 ).
No afterglow candidate is detected in the XRT error circle reported by 
Sakamoto et al. in this or any of the other early UVOT exposures.
 
The initial photometry upper limits for each UVOT filter are given 
below where Tmid is the average time of the exposure, in seconds,
since the BAT trigger and Mag_3 is the 3-sigma
upper limit for the magnitude. The quoted errors do not 
include the 0.1 mag systematic uncertainty in the photometric zero points.
 
   Filter    Tmid    Exposure  Mag_3
              (s)     (s)
==========================================
   White      179      98       20.4
              911      98       20.4

   V          434     393       20.1

   B         5054     197       20.7

   U         4850     197       20.3

   UVW1      4645     197       20.1

   UVM2      4440     197       20.1

   UVW2      5464     197       20.5

==========================================
 
The values quoted above are not corrected for the expected Galactic
extinction of E_{B-V} = 0.15 mag (Schlegel et al. 1998).

L. Calzoletti, E. Palazzi, E. Molinari, S. Covino, V. Testa, G. Tosti,
F. Vitali, P. Conconi, L.A. Antonelli, G. Cutispoto, G. Malaspina, 
N. Masetti, L. Nicastro, G. Chincarini, F.M. Zerbi, E. Meurs,
and P. Goldoni report on behalf of the REM/ROSS team:

"We observed the field of GRB 061202 (Sakamoto et al. GCN 5886
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 ) with
the robotic 60-cm REM telescope located at La Silla (Chile). A set of
observations was performed automatically in the optical and near
infrared (NIR) filters (V, R, I and J, H, K, z) starting on 2006 December 2
at 08:14 UT, about 4 minutes after the BAT trigger.
Preliminary analysis of the whole dataset does not show any new source 
inside the XRT error box.

The 3-sigma limiting magnitudes in the stacked optical R and NIR J, H, K 
images (800s, 600s, 1000s, 600s total integration time, respectively) are:

   R~18.0
   J~16.8
   H~16.4
   K~14.8

This message may be cited.".

M.Biskup, M.Cwiok, A.Majczyna, K.Malek, L.Mankiewicz, M.Molak, K.Nawrocki,
L.W.Piotrowski, M.Sokolowski, J.Uzycki, G.Wrochna, A.F.Zarnecki
on behalf of "Pi of the Sky" collaboration
http://grb.fuw.edu.pl

"Pi of the Sky" apparatus has moved to the Swift-BAT trigger 241963
and it has taken series of 10s exposures starting 170s after the GRB
(113s after the alert). No new object has been found within
the Swift-BAT error box. The limiting magnitude (unfiltered) is:
13.0 - 1 image,   08:14:35 - 08:14:35 UT
13.7 - 3 images,  08:14:35 - 08:15:12 UT
14.0 - 5 images,  08:14:35 - 08:15:39 UT
14.3 - 10 images, 08:14:35 - 08:16:47 UT

Three 10s images of this field have been taken at 07:33:22 - 07:34:02 UT
(37 minutes before the GRB). No new object is seen within the error box
and the limit is 13.2 magnitudo.

Martin Jelínek (IAA Granada, Spain),
Petr Kubánek (ISDC Versoix, Switzerland and ASU Ondrejov, Czech Rep.) and
Michael Prouza (Columbia University New York, USA and FZU Praha, Czech Rep.)
on behalf of the FRAM team, coordinated by FZU Praha, Czech Rep.

report

"The wide field camera of the FRAM telescope, located at
Pierre Auger observatory in Malargue, Argentina, followed
the GRB 061202 (Sakamoto et al. GCN 5886
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 , Sakamoto et al.
GCN 5887
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 , Calzoletti et al. GCN 5889
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 , Biskup et al. GCN
5891
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 , Swift trigger #241963).

3x 20s R-band (lambda_eff = 640nm) images were obtained
starting 134, 152, and 200s after the GRB (76.7s after
receiving the notification).

We do not detect any new source down to the limiting
magnitude R=~15.0."

this message may be cited

G. Stratta, M. Perri, M.L. Conciatore (ASDC), D. N. Burrows (PSU) and
T. Sakamoto (NASA/ORAU) report on behalf of the Swift XRT team:

We have analysed the first five orbits of Swift XRT data on the BAT GRB
061202 (Sakamoto, et al., GCN Circ. 5886
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 ; Sakamoto et al., GCN Circ.
5887
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 ).
A 7.6ks photon counting mode image provides a refined XRT position:

RA(J2000) = 07h 02m 05.55s
Dec(J2000) = -74d 41m 54.6"

with an uncertainty of 3.5" (90% containment). This is 8.6' away from
the centre of the refined BAT position quoted in GCN Circ. 5887
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  (Sakamoto
et al.), and 4.0" away from the initial XRT position quoted in
GCN Circ. 5886
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  (Sakamoto et al.).

The early X-ray light curve displays a large flare peaking at a count rate
of approximately 115 counts/s at T+140s followed by a shallow phase up to
about T+13ks. At later times the afterglow curve shows a decline with a
power-law decay with index alpha=-1.6+/-0.4.

The X-ray spectrum covering the time period from T+126s to T+310s is well
fit by an absorbed power-law with a photon index of 1.9+/-0.1 and column
density of (6.0+/-0.5)e21 cm**-2 (errors are at 90% confidence level).
We note the Galactic column density in the direction of the source is
1.16e21 cm**-2. The observed (unabsorbed) 0.3-10 keV flux for this
spectrum is 1.5e-09 (2.5e-09) erg/cm**2/s.

Assuming the X-ray emission continues to decline at the same rate, we
predict a 0.3-10 keV XRT count rate of 0.02 count/s at T+24hr, which
corresponds to an observed (unabsorbed) 0.3-10 keV flux of
1.2e-12 (2.0e-12) erg/cm**2/s.

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

S. Karpov, G. Beskin, S. Bondar, C. Bartolini, G. Greco, A. Guarnieri,
D. Nanni, A. Piccioni, F. Terra, E. Molinari, G. Chincarini, F.M. Zerbi,
S. Covino, V. Testa, G. Tosti, F. Vitali, L.A. Antonelli, P. Conconi,
G. Cutispoto, G. Malaspina, L. Nicastro, E. Palazzi, E. Meurs, P. Goldoni
report on behalf of the TORTOREM team:

The field of GRB 061202 (Sakamoto et al. GCN 5886
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 ) has been observed
by the TORTORA (Telescopio Ottimizzato per la Ricerca di Transienti
Ottici RApidi) wide-field fast camera (12 cm diameter, 20x25 deg FOV)
mounted on REM robotic 60-cm telescope located at La Silla (Chile). 
The burst was outside the camera field of view. The system was repointed
and the TORTORA began to acquire frames at 08:13:16 UT 
(92 sec after trigger) with 7.5 Hz frame frequency (0.128 s exposure).

The summation of 100 frames with 12.8 s. effective exposure 
did not reveal any source down to the B = 11.3 mag (3-sigma)
on bright sky background.

We performed the Fourier analysis of 10 min data set to search for the
periodic signal at the GRB position. The upper limit for the amplitude
of sinusoidal variability is B=14.0 (1-sigma) over the 0.1 - 3.5 Hz
range.

The message may be cited.

K. Onda, M. Tashiro, K. Abe, Y. Sato, M. Suzuki, Y. Urata (Saitama U.),
K. Yamaoka, S. Sugita (Aoyama Gakuin U.), M. Ohno, T. Takahashi,
T. Asano, T. Uehara, Y. Fukazawa (Hiroshima U.), Y. Terada, M. Suzuki,
T. Tamagawa (RIKEN), T. Enoto, R. Miyawaki, K. Kokubun, K. Makishima
(Univ. of Tokyo), K. Nakazawa, T. Takahashi (ISAS/JAXA),
 S. Hong (Nihon U.), on behalf of the Suzaku WAM team report:

The bright, long burst, GRB 061202 (Sakamoto et al., GCN 5886
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 ; 5887),
triggered the Suzaku Wide-band All-sky Monitor (WAM),
which covers the energy range of 50 keV - 5 MeV, at 08:12:59.625 (UT).
A FRED type peak and following weak and broad hump were seen in the 
 WAM light curve. The T90 duration was about 64 seconds. The fluence 
in 100 - 500 keV was (5.0 +- 0.6)x10^-6 erg/cm2, while the 1-s peak
flux was 0.80 +- 0.05 photons/cm2/s in the same energy range.

Preliminary result shows that the spectrum of the main peak, integrated
during T0 to T0+50s is well-described with a single power-law model with 
the photon index of 1.78 (-0.22, +0.21). All the quoted errors are at 
statistical 90% confidence level, while systematic errors are not included.

The WAM light curve of this event is available at
http://www.astro.isas.jaxa.jp/suzaku/HXD-WAM/WAM-GRB/grb/grb_table.html