GRB 110709A

A. Zauderer, E. Berger, and W. Fong (Harvard) report on behalf of a 
larger collaboration:

We observed the position of GRB 110709A (GCN #12118
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 ) with the EVLA at
5.8 GHz and 22 GHz starting on 2011 July 10.12 UT (~12 hours after the
burst).  In ~20 min integration time on source at each frequency, no
radio source is detected within the XRT error circle (GCN #12123
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 ) to a
3-sigma limit of 60 microJy/bm (5.8 GHz) and 104 microJy/bm (22 GHz).

We acknowledge the EVLA staff for their support of these observations.

Y. Hanabata, T. Uehara, T. Takahashi, M. Mizuno, M. Ohno, Y. Fukazawa
(Hiroshima U.), T. Yasuda, Y. Terada, M. Tashiro, W. Iwakiri,
K. Takahara (Saitama U.), S. Sugita (Nagoya U.), K. Yamaoka (Aoyama
Gakuin U.), M. Kokubun, T. Takahashi (ISAS/JAXA), Y. E. Nakagawa (Waseda U.),
N. Ohmori, M. Akiyama, M. Yamauchi (Univ. of Miyazaki), Y. Urata,
P. Tsai, C-J. Chuang (NCU), K. Nakazawa, K. Makishima (Univ. of Tokyo),
on behalf of the Suzaku WAM team, report:

The bright long GRB110709A (Swift/BAT trigger #456939, GCN 12118
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 ;
Holland et al.) triggered the Suzaku Wide-band All-sky Monitor (WAM)
which covers an energy range of 50 keV - 5 MeV at 15:24:27.951 UT (=T0).

The observed light curve shows multiple peaks starting at T0 s, ending
at T0+45 s, with a duration (T90) of about 41.5 seconds. The fluence in
100 - 1000 keV was 2.02 (-0.26, +0.10) x 10^-5 erg/cm^2. The 1-s peak
flux measured from T0+7 s was 4.10 (-0.96, +0.10) photons/cm^2/s in the
same range.

Preliminary result shows that the time-averaged spectrum from T0 s to
T0+45 s is well fitted by a power-law with exponential cutoff model:
 dN/dE ~  E^{-alpha} * exp(-(2-alpha)*E/Epeak) with
 alpha       1.37 (-0.61, +0.49), and
 Epeak       431 (-113, +173) keV (chi^2/d.o.f. = 18.0/12).

We also shows the results with the same spectrum fitted by a GRB Band
model fixing beta of 2.5,
the low-energy photon index alpha: 1.34 (-0.49, +0.74)
and the peak energy Epeak: 407 (-96, +158) keV (chi^2/d.o.f = 17.4/12). 
All the quoted errors are at statistical 90% confidence level.

The light curves for this burst are available at:
http://www.astro.isas.jaxa.jp/suzaku/HXD-WAM/WAM-GRB/grb/trig/grb_table.html

S. T. Holland (CRESST/USRA/GSFC)
reports on behalf of the Swift/UVOT team:

      The Swift/UVOT observed the field of GRB 110709A starting 56 s
after the BAT trigger (Holland et al., 2011, GCNC 12118).  Settled
observations started at 74 s.  We do not detect an optical afterglow
at the UVOT-enhanced XRT position (Osborne, et al., 2011, GCNC 12123)
in any of the UVOT filters.  Preliminary 3-sigma upper limits for
detecting a source in the finding charts and in the co-added images,
are

Filter       TSTART       TSTOP  ESPOSURE       Mag
---------------------------------------------------
white (FC)       74         224       147     >21.7
    u (FC)      287         536       246     >21.0
white (FC)      865        1014       147     >21.8
---------------------------------------------------
    v           616        7409       549     >20.9
    b           542      19,323      2148     >22.5
    u           287      18,560      2337     >22.2
 uvw1           666      17,646      1383     >21.7
 uvm2          5978        7614       393     >20.7
 uvw2           591        7204       490     >21.2
white            74      13,546      1538     >23.1
---------------------------------------------------

     The quoted magnitudes and upper limits have not been corrected
for the large, but uncertain, Galactic extinction along the line of
sight to this burst (E_{B-V} = 0.02 mag, Schlegel et al. 1998, ApJS,
500, 525).

J. Kelemen,(Konkoly Obs.)
on behalf of the GRB OT observing program at the Konkoly Observatory.

We observed the field of GRB 110709A (trigger=456939) S. T. Holland et al.
(GCN 12118
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 ) using the enhanced Swift-XRT position provided by P. A. Evans.
(GCN 12119
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 ) with a 60/90 cm Schmidt telescope located at the Mountain Station
of the Konkoly Observatory. We coadded 6 red sensitive CCD images without
filter with 300 sec exposure time each. On the coadded frame we checked the
position RA (J2000) = 15:55:33.86 Dec (J2000) = +40:55:28.0 provided by J. P.
Osborne et al. (GCN 12123
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 ). We found a faint marginaly visible source at the
position RA (J2000) = 15:55:33.96 Dec (J2000) = +40:55:27.7 within the error
circle of the astrometricaly corrected X-ray position. Based on nearby UCAC-3
stars the brightness of this object in the R band is 21.4 +/- 0.2  magnitude.    


Time from
the trigger    magnitude       Band
----------------------------------------
27374 sec      21.4 +/- 0.2      R

G. Stratta (ASDC), V. D'Elia (ASDC) and S. T. Holland
(CRESST/USRA/GSFC) report on behalf of the Swift-XRT team:

We have analysed 9.6 ks of XRT data for GRB 110709A (Holland  et al.
GCN Circ. 12118
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 ), from 71 s to 19.3 ks after the  BAT trigger. The data
comprise 565 s in Windowed Timing (WT) mode with the remainder in
Photon Counting (PC) mode. The enhanced XRT position for this burst was
given by Osborne et al. (GCN. Circ 12119).

The late-time light curve (from T0+5.2 ks) can be modelled with  a
power-law decay with a decay index of alpha=1.72 (+/-0.10).

A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index	of 2.21 (+0.09, -0.08). The
best-fitting absorption column is  7.5 (+0.6, -0.5) x 10^21 cm^-2, in
excess of the Galactic value of 1.5 x 10^20 cm^-2 (Kalberla et al.
2005). The PC mode spectrum has a photon index of 2.07 (+/-0.11) and a
best-fitting absorption column of 7.3 (+/-0.7) x 10^21 cm^-2. The
counts to observed (unabsorbed) 0.3-10 keV flux conversion factor
deduced from this spectrum  is 5.0 x 10^-11 (1.0 x 10^-10) erg cm^-2
count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:	     7.3 (+/-0.7) x 10^21 cm^-2
Galactic foreground: 1.5 x 10^20 cm^-2
Excess significance: 17.8 sigma
Photon index:	     2.07 (+/-0.11)

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00456939.

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

D. Kuroda (OAO, NAOJ),  H. Hanayama, T. Miyaji, J. Watanabe (IAO, NAOJ),
K. Yanagisawa (OAO, NAOJ), S.Nagayama (NAOJ), M. Yoshida (Hiroshima),
K. Ohta (Kyoto) and N. Kawai(Tokyo Tech)
report on behalf of the MITSuME collaboration:

We observed the field of GRB 110709A (Holland et al., GCN 12118
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 )
with the optical three color (g', Rc and Ic) CCD camera attached
to the Murikabushi 1m telescope of Ishigakijima Astronomical
Observatory.

The observation started on 15:27:30 UT (~3 min after the burst).
We did not find any new point source within the Enhanced XRT circle
(Osborne, et al., GCN 12123
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 ) in all the three bands.

Three sigma upper limits of the OT are listed below. We used
SDSS catalog for flux calibration.


T0+[day]   MID-UT   T-EXP[sec]    g'     Rc     Ic
------------------------------------------------------
0.00487    15:31:30     420.0    >19.9  >19.8  >18.7
------------------------------------------------------
T0+ : Elapsed time after the burst [day]
T-EXP: Total Exposure time [sec]

S. Golenetskii, R.Aptekar, D. Frederiks, E. Mazets, V. Pal'shin,
P. Oleynik, M. Ulanov, D. Svinkin, and T. Cline on behalf
of the Konus-Wind team, report:

The long GRB 110709A (Swift-BAT trigger #456939:
Holland et al., GCN 12118
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 ; Sakamoto et al., GCN 12127
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 )
triggered Konus-Wind at T0=55470.576s UT (15:24:30.062)

The burst light curve consists of several partially overlapped
pulses, a total duration of the burst ~60 s.
The emission is seen up to ~5 MeV.
The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB110709_T55470/

As observed by Konus-Wind the burst
had a fluence of (3.7 � 0.3)x10-5 erg/cm2,
and a 256-ms peak flux, measured from T0+12.544 s,
of (4.1 � 0.4)x10-6 erg/cm2/s
(both in the 20 keV - 5 MeV energy range).

The time-integrated spectrum of the burst
(measured from T0 to T0+48.896 s) is best fitted
in the 20 keV - 5 MeV range by a power law
with exponential cutoff model, for which
alpha = -1.03 (-0.07, +0.07),
and Ep = 356(-34, +42) keV,
chi2 = 72.6/76 dof.

The spectrum at the maximum count rate
(measured from T0+7.963 to T0+16.128 s) is best fitted
in the 20 keV - 5 MeV range by a power law
with exponential cutoff model, for which
alpha = -0.72 (-0.12, +0.13),
and Ep = 523(-68, +87) keV,
chi2 = 72.4/76 dof.

All the quoted results are preliminary.
All the quoted errors are at the 90% confidence level.

J.C.Tello, J. Gorosabel, A. Castro-Tirado, M. Fernandez (IAA-CSIC Granada, Spain) and N. Huelamo (CAB-CSIC Madrid, Spain) reports on behalf of a larger collaboration:

We observed GRB110709A detected by Swift/BAT (Holland et al. 2011, GCN 12118
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 ) with CAHA 1.23m and OSN 1.5m telescopes.

Centro Astron�mico Hispano Alem�n (CAHA) 1.23m's observation in R filter lasted from July 9th 20:35 to 21:42 UT (e.g. 5.18-6.29 hours after trigger). At 8x420 sec co-added frames centred on XRT position (Evans et al. 2011, GCN 12119
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 ) we do not detect any new source down to limiting magnitude R=22.7, calibrated against USNO B1.0.

The I band frames from 1.5m Observatorio de Sierra Nevada (OSN) were taken on July 9th. On co-added I band frames, taken between 20:44 and 22:03 UT, with total exposure 4200 sec, we report limiting magnitude I=20.4 (calibrated against USNO B1.0). On V frames with total duration 1200 sec, acquired between 21:24 and 21:42 UT, we do not see any new source down to limiting magnitude V=21.6 (Calibrated against GSC 2.3).


This message may be cited.

V. Connaughton (UAH) reports on behalf of the Fermi GBM Team:

"At 15:24:27.37 UT on 09 July 2011, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 110709A (trigger 331917869 / 110709642),
which was also detected by the Swift/BAT (Holland et al. 2011,
GCN 12118
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 ) and the Swift/XRT (Evans et al. 2011,  GCN 12119
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 ).
The GBM on-ground location is consistent with the Swift position.

The angle from the Fermi LAT boresight at trigger time was 54 degrees.
Approximately 6 - 200 s from trigger time, the Fermi spacecraft executed
an automatic maneuver in response to a command from GBM, in
order to place the burst closer to the LAT boresight, and observed
this position for the following 2.5 hours, subject to Earth limb
constraints.

The GBM light curve shows several bright peaks from trigger time
to 50-s post-trigger, with a duration (t90) of 43.5 s (50-300 keV).
The time-averaged spectrum from T0-4.096 s to T0+62.5 s is
best fit by a power law function with an exponential
high-energy cutoff.  The power law index is -1.16 +/- 0.02 and
the cutoff energy, parametrized as Epeak, is 533 +/- 37 keV.

The event fluence (10-1000 keV) in this time interval is
(4.43 +/- 0.07)E-5 erg/cm^2. The 64 ms peak photon flux measured
starting from T0+25.28 s in the 10-1000 keV band
is 15.4 +/- 1.7 ph/s/cm^2.

The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."

T. Sakamoto (GSFC/UMBC), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),
J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC), S. T. Holland (CRESST/USRA/GSFC),
H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC), D. M. Palmer (LANL),
M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (MSU)
(i.e. the Swift-BAT team):
 
Using the data set from T-239 to T+733 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 110709A (trigger #456939)
(Holland, et al., GCN Circ. 12118
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 ).  The BAT ground-calculated position is
RA, Dec = 238.895, 40.918 deg, which is 
   RA(J2000)  =  15h 55m 34.8s 
   Dec(J2000) = +40d 55' 06.4" 
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 91%.
 
The mask-weighted light curve shows at least 8 peaks starting at T-5 sec,
with the brightest peak at ~T+34 sec, and returning to background
at ~T+100 sec.  T90 (15-350 keV) is 44.7 +- 1.0 sec
(estimated error including systematics).
 
The time-averaged spectrum from T-4.3 to T+65.5 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.24 +- 0.03.  The fluence in the 15-150 keV band is 1.0 +- 0.02 x 10^-05 erg/cm2.
The 1-sec peak photon flux measured from T+34.31 sec in the 15-150 keV band
is 6.2 +- 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/456939/BA/

L.P. Xin, M,Zhai, Y.L. Qiu, J.Y. Wei, J. Wang, J.S. Deng, 
C. Wu, X. H. Han on behalf of EAFON report:

We began to observe GRB110709A (Holland et al. GCN 12118
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 )
with Xinglong TNT telescope at 15:30:49 (UT), 6 min after 
the burst. A series of R-band images were obtained. 
After combining 10*20s R-band images, no any new source was found within
the errorbox  of X-ray counterpart,down to 3 sigma 
upper limit of R~19.1 mag at the mean time of 7.5 min after 
the burst. 

This message may be cited.

For more information about Xinglong GRBs Follow-up
observations, please visit the website:
http://www.xinglong-naoc.org/grb/

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

Using 3951 s of XRT Photon Counting mode data and 7 UVOT
images for GRB 110709A, 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 = 238.89144, +40.92427 which is equivalent
to:

RA (J2000): 15h 55m 33.95s
Dec (J2000): +40d 55' 27.4"

with an uncertainty of 1.5 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.

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

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

  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 Tunka(Siberia) was pointed to the GRB110709.64 29 sec s after 
notice time and 54 sec after GRB time at 2011-07-09 15:25:23.161 UT. On 
our first (10s exposure) set we haven`t found optical transient within 
SWIFT error-box (Holland et al., GCN 110709A
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 ).
The 3-sigma upper limit has been about 16.0 mag (V band + polarizator)
The message may be cited.

P.A. Evans (U. Leicester) reports on behalf of the Swift-XRT team:

Using  promptly downlinked XRT event data for GRB 110709A, we find an
enhanced XRT position of the afterglow: RA, Dec: 238.8911, 40.9244
which is equivalent to:
   RA (J2000)  = 15 55 33.86
   Dec (J2000) = +40 55 28.0
with an uncertainty of 2.0 arc sec (radius, 90% confidence). Analysis
of the promptly available data is online at
http://www.swift.ac.uk/sper/456939.

Position enhancement is is described by Goad et al. (2007, A&A, 476,
1401) and Evans et al. (2009, MNRAS, 397, 1177).

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

S. T. Holland (CRESST/USRA/GSFC), S. D. Barthelmy (GSFC),
D. N. Burrows (PSU), J. R. Cummings (NASA/UMBC), V. D'Elia (ASDC),
B. Gendre (ASDC), C. Gronwall (PSU), H. A. Krimm (CRESST/GSFC/USRA),
C. B. Markwardt (NASA/GSFC), D. M. Palmer (LANL),
P. Romano (INAF-IASFPA), M. H. Siegel (PSU) and
E. Troja (NASA/GSFC/ORAU) report on behalf of the Swift Team:

At 15:24:29 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 110709A (trigger=456939).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 238.895, +40.898, which is 
   RA(J2000)  =  15h 55m 35s
   Dec(J2000) = +40d 53' 51"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve shows 8 roughly equal bright peaks
with a total duration of about 50 sec.  The peak count rate
was ~12,000 counts/sec (15-350 keV), at ~18 sec after the trigger. 

The XRT began observing the field at 15:25:34.7 UT, 65.6 seconds after
the BAT trigger. XRT found a bright, uncatalogued X-ray source located
at RA, Dec 238.8931, +40.9232 which is equivalent to:
   RA(J2000)  = 15h 55m 34.34s
   Dec(J2000) = +40d 55' 23.5"
with an uncertainty of 4.9 arcseconds (radius, 90% containment). This
location is 92 arcseconds from the BAT onboard position, within the BAT
error circle. No event data are yet available to determine the column
density using X-ray spectroscopy. 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 73 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 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
0.02. 

Burst Advocate for this burst is S. T. Holland (Stephen.T.Holland 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.)