GRB 111204A

E. Sonbas (GSFC/USRA/Adiyaman Univ.), W. H. Baumgartner (GSFC/UMBC),
A. P. Beardmore (U Leicester), D. N. Burrows (PSU),
S. Campana (INAF-OAB), N. Gehrels (NASA/GSFC),
S. T. Holland (CRESST/USRA/GSFC), E. A. Hoversten (PSU),
K. L. Page (U Leicester), D. M. Palmer (LANL), M. H. Siegel (PSU),
C. A. Swenson (PSU) and T. N. Ukwatta (MSU) report on behalf of the
Swift Team:

At 13:37:28 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 111204A (trigger=509018).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 336.641, -31.395 which is 
   RA(J2000) = 22h 26m 34s
   Dec(J2000) = -31d 23' 41"
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 80 sec.  The peak count rate
was ~400 counts/sec (15-350 keV), at ~50 sec after the trigger. 

The XRT began observing the field at 13:40:08.0 UT, 159.7 seconds after
the BAT trigger. Using promptly downlinked data we find an uncatalogued
X-ray source located at RA, Dec 336.62912, -31.37514 which is
equivalent to:
   RA(J2000)  = 22h 26m 30.99s
   Dec(J2000) = -31d 22' 30.5"
with an uncertainty of 3.8 arcseconds (radius, 90% containment). This
location is 80 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.  We
cannot determine whether the source is fading at the present time. 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density consistent with the Galactic value of 1.08
x 10^20 cm^-2 (Kalberla et al. 2005). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 143 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 34% of
the XRT error circle. The typical 3-sigma upper limit has been about 19.6 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
0.01. 

Burst Advocate for this burst is E. Sonbas (edasonbas AT yahoo.com). 
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 OPS NOTE(04dec11): Per author's request, the contact address for ES
has been changed to edasonbas@yahoo.com .]

A.P. Beardmore, P.A. Evans, M.R. Goad and J.P. Osborne (U. Leicester) 
report on behalf of the Swift-XRT team.

Using 175 s of XRT Photon Counting mode data and 1 UVOT
images for GRB 111204A, 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 = 336.62848, -31.37479 which is equivalent
to:

RA (J2000): 22h 26m 30.84s
Dec (J2000): -31d 22' 29.3"

with an uncertainty of 2.1 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) and Evans
et al. (2009, MNRAS, 397, 1177).

This circular was automatically generated, and is an official product of the
Swift-XRT team.

A.V. Parhomenko, A. Tlatov, D. Dormidontov
  Kislovodsk Solar Station of the Pulkovo Observatory


  K.Ivanov, V.A.Poleshchuk, S.Yazev, N.M.Budnev, O.Gres, 
O.Chuvalaev,E.Konstantinov,
  Irkutsk State University

  E. Gorbovskoy, V. Lipunov, V.Kornilov, D.Kuvshinov, A.Belinski, N.Tyurina, 
N.Shatskiy, P.Balanutsa, V.V.Chazov, P.V.Kortunov, A.Kuznetsov, D.Zimnukhov, M. 
Kornilov,A.Sankovich
  Sternberg Astronomical Institute, Moscow State University


  V.Krushinski, I.Zalozhnich, T.Kopytova, A. Popov
  Ural State University, Kourovka

  V.Yurkov, Yu.Sergienko, D.Varda, I.Kudelina
  Blagoveschensk Educational State University, Blagoveschensk

MASTER II  robotic telescope (MASTER-Net: http://observ.pereplet.ru) 
located in Kislovodsk was pointed to the  GRB111204A (Sonbas et al., GCN 
Circ 12612
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 ) 115 sec after GRB trigger time  after sunset.
Unfortunately our first (20s exposure) images are saturated.

The first unsaturated  images was 2828 sec after GRB 
time at 2011-12-04 14:24:36.065 UT. On our 180s exposure white+polarizator 
set we  haven`t found optical transient  within SWIFT error-box.
The 5-sigma upper limit has been about 15.0  mag.

Our coaded image (started at 2011-12-04 15:00:58 UT, 3240s effective 
exposition) has limit 19.2 mag.

  The message may be cited.

S. R. Oates (MSSL-UCL) and E. Sonbas (GSFC/USRA/Adiyaman_Univ.)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 111204A
143 s after the BAT trigger (Sonbas et al., GCN Circ. 12612
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 ).
No optical afterglow consistent with the XRT position 
(Beardmore et al., GCN Circ. 12614
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 ) is detected in the initial UVOT exposures.
Preliminary 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first
finding chart (FC) exposure and subsequent exposures are:

Filter         T_start(s)   T_stop(s)      Exp(s)         Mag

white_FC           143          293          147         >20.4
white              143         5439          541         >21.6
v                 4214         5851          393         >19.6
b                 3599        11889         1054         >20.8
u                  302        11204         1116         >21.3
w1                4624        10291         1133         >20.7
m2                4419        15631          869         >21.1
w2                4009         5646          393         >20.8

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.01 in the direction of the burst
(Schlegel et al. 1998).

C. B. Markwardt (GSFC), 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), D. M. Palmer (LANL), A. M. Parsons (GSFC),
T. Sakamoto (GSFC/UMBC), G. Sato (ISAS),
E. Sonbas (GSFC/USRA/Adiyaman Univ.), M. Stamatikos (OSU),
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 111204A (trigger #509018) (Sonbas, et al., GCN Circ. 12612
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 ).
The BAT ground-calculated position is RA, Dec = 336.651, -31.414 deg
which is
   RA(J2000)  =  22h 26m 36.2s
   Dec(J2000) = -31d 24' 49.4"
with an uncertainty of 2.2 arcmin, (radius, sys+stat, 90%
containment). The partial coding was 75%.

The mask-weighted light curve shows two peaks. Initial peak starts
at the trigger time and last until ~T+10 sec. The second broad peak
starts at ~T+43 sec, peaks at ~T+48 sec, and ends at ~T+90 sec.
T90 (15-350 keV) is 48.0 +/- 22.6 sec (estimated error including
systematics).

The time-averaged spectrum from T+33.0 to T+81.0 sec is best fit by a
simple power-law model.  The power law index of the time-averaged
spectrum is 1.83 +/- 0.30.  The fluence in the 15-150 keV band is
4.7 +/- 0.9 x 10^-07 erg/cm2. The 1-sec peak photon flux measured
from T+56.50 sec in the 15-150 keV band is 0.3 +/- 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/509018/BA/

M.C. Stroh (PSU), D.N. Burrows (PSU), K.L. Page (U. Leicester), C.
Pagani (U. Leicester), A.P. Beardmore (U. Leicester), V. D'Elia (ASDC),
V. Mangano (INAF-IASFPA), A. Melandri (INAF-OAB), J.A. Kennea (PSU) and
E. Sonbas report on behalf of the Swift-XRT team:

We have analysed 8.4 ks of XRT data for GRB 111204A (Sonbas  et al. GCN
Circ. 12612
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 ), from 157 s to 27.3 ks after the  BAT trigger. The data
are entirely in Photon Counting (PC) mode. The enhanced XRT position
for this burst was given by Beardmore et al. (GCN. Circ 12614).

The light curve can be modelled with  a power-law decay with a decay
index of alpha=1.86 (+0.31, -0.17).

A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.2 (+/-0.4). The
best-fitting absorption column is  9 (+16, -8) x 10^20 cm^-2,
consistent with the Galactic value of 1.1 x 10^20 cm^-2 (Kalberla et
al. 2005). The counts to observed (unabsorbed) 0.3-10 keV flux
conversion factor deduced from this spectrum  is 6.0 x 10^-11 (6.4 x
10^-11) erg cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:	     9 (+16, -8) x 10^20 cm^-2
Galactic foreground: 1.1 x 10^20 cm^-2
Excess significance: <1.6 sigma
Photon index:	     1.2 (+/-0.4)

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00509018.

This circular is an official product of the Swift-XRT team.

D. A. Kann (Tautenburg Observatory), F. Olivares E., and J. Greiner,
(both MPE Garching) report on behalf of the GROND team:

We observed the field of GRB 111204A (Swift trigger 509018; Sonbas et
al., GCN #12612
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 ) simultaneously in g'r'i'z'JHK with GROND (Greiner et
al. 2008, PASP, 120, 405) mounted at the 2.2 m ESO/MPI telescope at La
Silla Observatory (Chile). Observations started on December 5, 2011,
at 00:38 UT, 11 hours after the GRB trigger, during twilight. They were
performed at an average seeing of 1".1 and at an airmass of 1.2 - 2.2.

Based on co-added images of 5900 s integration time in g'r'i'z' and
4800 s in JHK, centered 0.5253 days after the trigger, no new sources
within the enhanced 1".9 XRT error circle (RA = 22:26:30.81, Dec. =
-31:22:29.3; Beardmore et al., GCN #12614
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 , updated version from the
Enhanced XRT Position page) are detected, and the following specific upper
limits (all in the AB magnitude system) are found:

g' > 24.5
r' > 24.9
i' > 24.4
z' > 24.0
J > 22.3
H > 21.6
K > 20.5

Magnitudes were calibrated against GROND zeropoints in g'r'i'z' and 2MASS
field stars in JHK. No corrections for the expected Galactic foreground
extinction were made, which correspond to a reddening of E(B-V)=0.012 mag
in the direction of the burst (Schlegel et al. 1998).

D. Fugazza, S. Covino, A. Melandri (INAF-OAB), V. D'Elia (INAF-OAR), P.
D'Avanzo, S. Campana, G. Tagliaferri (INAF-OAB) and E. Palazzi
(INAF-IASFBo) on behalf of a larger collaboration report:

We observed the field of GRB 111204A (Sonbas et al. GCN 12612
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 ) with the
3.6m TNG equipped with the NICS near-infrared camera. A sequence of JHK
band images were acquired starting on Dec 04.792 UT (i.e. ~5.4 hours after
the burst event) lasting 15, 10 and 20 minutes, respectively.

We do not detect any object inside the enhanced XRT position (Beardmore et
al. GCN 12614
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 ) down to the following limiting magnitudes (3sigma c.l.,
calibrated against the 2MASS catalogue):

J > 19.7
H > 18.8
Ks > 18.8

We thank the TNG staff for their support, in particular Luca di Fabrizio
and Gianni Tessicini.