GRB 110719A

A. Zauderer, G. Petitpas and E. Berger (Harvard/CfA) report on behalf of 
a larger collaboration:

"We observed GRB 110719A (GCN #12173
Loading...
 
 ) with the SMA at 345 GHz starting 
on 2011 July 19.6 (7.5 hours after the burst) for a total integration 
time on source of 4.6 hours.  No counterpart is detected within the XRT 
error circle (GCN #12176
Loading...
 
 ) to a 3-sigma upper limit of 2.1 mJy/bm.

We acknowledge and thank the SMA observatory staff for their support
of these rapid response observations."

T. Sakamoto (UMBC/GSFC), D. Donato (UMD/GSFC), N. Gehrels (GSFC),
T. Okajima (GSFC), Y. Urata (NCU)

We observed the field of GRB 110719A detected by Swift (trigger #457553; 
Sakamoto et al., GCN Circ. 12173
Loading...
 
 ) with the 14-inch Goddard Robotic 
Telescope (GRT) located at the Goddard Geophysical
and Astronomical Observatory (http://cddisa.gsfc.nasa.gov/ggao/).

A total 127 images of 5 sec exposures were taken in the R filter 
starting from July 19 06:11:29 (UT), about 137 seconds after the trigger 
(92 seconds after the BAT position notice), and stopped on July 19 
06:31:01 (UT).  We do not detect the optical afterglow both in the 
individual images and the stacked image inside the XRT error circle 
(Goad et al., GCN #12176
Loading...
 
 ).  The estimated five sigma upper limit of 
the combined image (total exposure of 635 sec) is ~18.2 mag using 
the USNO-B1 catalog.

M.Sokolowski,T.Batsch,A.Majcher,A.Majczyna,K.Nawrocki,J.Uzycki,G.Wrochna (IPJ, Swierk),
M.Cwiok,W.Dominik,L.W.Piotrowski,A.F.Zarnecki (University of Warsaw),
K.Malek,L.Mankiewicz,R.Opiela,M.Siudek,V.Repei (CFT PAN),
G.Kasprowicz,M.Zaremba (Warsaw University of Technology),
from the "Pi of the Sky" collaboration ( http://grb.fuw.edu.pl ).

The wide field "Pi of the Sky South" apparatus, installed in the private
observatory of Alain Maury in San Pedro de Atacama
( http://grb.fuw.edu.pl/pi/index.html#spda_site.htm ) has observed
the position of GRB 110719A 105s after the GRB.
No new object has been found within the Swift-XRT error box.

t_start - t0    start (UT)   end (UT)     3-sigma limit
   105sec        06:10:56   06:11:06 UT      11.0 mag

The field was observed until 06:29:34 UT, no new object brighter then 11.0
mag was observed. The limit on 20 coadded images is 11.5 mag.

We acknowladge great support received from Alain Maury at SPdA Observatory.

Andrew J. Levan (Univ. Warwick), Stefano Covino, Andrea Melandri (INAF/ 
OABr), Daniele Malesani, Antonio de Ugarte Postigo, Johan P.U.
Fynbo (DARK/NBI), report on behalf of the X-shooter GRB GTO  
collaboration:

We observed the field of GRB 110719A (Sakamoto et al., GCN 12173
Loading...
 
 ) with  
the ESO VLT equipped with X-shooter. We could only take a short
acquisition image, with mean time 2011 July 19.42 UT (3.95 hr after  
the GRB). No new object is detected within the refined XRT error circle
(Goad et al., GCN 12176
Loading...
 
 ), down to a limiting magnitude z > 22.5 (AB),  
calibrated against SDSS stars in the field.

We note that the inferred limit on the broad-band spectral slope is  
beta_OX < 0.64 (computed between the z band and 1 keV). Given the hard
X-ray spectral slope beta_X = 0.58 (Pagani et al., GCN 12178
Loading...
 
 ), our non  
detection is consistent with the extrapolation of the X-ray spectrum.
Our data do not allow to classify GRB 110719A as dark.

M. De Pasquale, C.J. Saxton (MSSL-UCL) and T. Sakamoto (NASA/UMBC)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 110719A
121 s after the BAT trigger (Sakamoto et al., GCN Circ. 12173
Loading...
 
 ).
No optical afterglow consistent with the XRT position (Pagani et al., GCN 
Circ. 12173
Loading...
 
 ) is detected in the initial UVOT exposures and in the 
summed exposures taken in all filters.
Preliminary 3-sigma upper limits using the UVOT photometric system
(Poole et al. 2008, MNRAS, 383, 627) for the first finding chart (FC)
exposure and subsequent exposures are:

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

white_FC           121          271          147 	>20.2
u_FC               279          529          246 	>19.2
white              121        17904         1080 	>21.3
v                 4848        10563         1143 	>20.2
b                  535        17151         1101 	>21.1
u                  279        16239         1328 	>20.5
w1                5258        12124          836 	>20.4
m2                5053        11468         1082 	>20.8
w2                4643         6280          393 	>20.2

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.04 in the direction of the burst
(Schlegel et al. 1998).

C. Pagani (U. Leicester) and T. Sakamoto (NASA/UMBC) report on behalf
of the Swift-XRT team:

We have analysed 4.5 ks of XRT data for GRB 110719A (Sakamoto  et al.
GCN Circ. 12173
Loading...
 
 ), from 117 s to 12.1 ks after the  BAT trigger. The
data comprise 258 s in Windowed Timing (WT) mode with the remainder in
Photon Counting (PC) mode. The enhanced XRT position for this burst was
given by Goad et al. (GCN. Circ 12176).

The light curve can be modelled with a series of power-law decays. The
initial decay index is alpha=0.59 (+0.26, -0.30). At T+219 s  the decay
steepens to an alpha of 2.6 (+/-0.4) before breaking again at T+1393 s
to a final decay with index alpha=0.7 (+0.7, -0.6).

A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index	of 1.39 (+0.13, -0.12). The
best-fitting absorption column is  9.0 (+3.8, -3.4) x 10^20 cm^-2, in
excess of the Galactic value of 4.0 x 10^20 cm^-2 (Kalberla et al.
2005). The PC mode spectrum has a photon index of 1.58 (+0.26, -0.15)
and a best-fitting absorption column consistent with the Galactic
value. The counts to observed (unabsorbed) 0.3-10 keV flux conversion
factor deduced from this spectrum  is 4.6 x 10^-11 (4.9 x 10^-11) erg
cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:	     4.0 (+5.9, -0) x 10^20 cm^-2
Galactic foreground: 4.0 x 10^20 cm^-2
Excess significance: <1.6 sigma
Photon index:	     1.58 (+0.26, -0.15)

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00457553.

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

A. Volnova (SAI MSU), L. Elenin (ISON), I. Molotov (ISON), A. Pozanenko 
(IKI) report on behalf of larger GRB  follow-up collaboration:

We observed the field of  GRB 110719A (Sakamoto  et al. GCN 12173
Loading...
 
 ) with 
0.45-m telescope �f ISON-NM observatory  on  July 19 starting (UT) 06:54:39. 
We took 30 unfiltered images.  In a stacked image we do not detect any 
source within enhanced XRT error circle (Goad et al., GCN 12176
Loading...
 
 ) up to 
19.7m.  The photometry is based on the USNO-B1.0  1245-0023215 star 
(RA=01:38:11.95, Dec=+34:35:52.6) assuming R=13.72.

T0+         Filter,   Exposure, OT,   Upper Limit
(mid, d)               (s)

0.04370  none     30x60s     n/d    19.7

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

Using 1852 s of XRT Photon Counting mode data and 1 UVOT
images for GRB 110719A, 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 = 24.58085, +34.58616 which is equivalent
to:

RA (J2000): 01h 38m 19.40s
Dec (J2000): +34d 35' 10.2"

with an uncertainty of 2.5 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.

W. H. Baumgartner (GSFC/UMBC), S. D. Barthelmy (GSFC), J. R. Cummings (GSFC/UMBC),
N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC),
D. M. Palmer (LANL), T. Sakamoto (GSFC/UMBC), M. Stamatikos (OSU),
J. Tueller (GSFC), T. N. Ukwatta (MSU)
(i.e. the Swift-BAT team):
 
Using the data set from T-60 to T+243 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 110719A (trigger #457553)
(Sakamoto, et al., GCN Circ. 12173
Loading...
 
 ).  The BAT ground-calculated position is
RA, Dec = 24.570, 34.578 deg, which is 
   RA(J2000)  =  01h 38m 16.8s 
   Dec(J2000) = +34d 34' 39.0" 
with an uncertainty of 1.8 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 30%.
 
The mask-weighted light curve shows a FRED-like peak starting at ~T-5 sec,
peaking at ~T+1 sec, and returning to background around T+95 sec.
T90 (15-350 keV) is 41.0 +- 7.4 sec (estimated error including systematics).
 
The time-averaged spectrum from T-2.0 to T+42.9 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.63 +- 0.15.  The fluence in the 15-150 keV band is 1.8 +- 0.2 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+2.02 sec in the 15-150 keV band
is 1.3 +- 0.3 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/457553/BA/

T. Sakamoto (NASA/UMBC), A. P. Beardmore (U Leicester),
J. R. Cummings (NASA/UMBC), M. De Pasquale (UCL-MSSL),
C. Guidorzi (U Ferrara), O. M. Littlejohns (U Leicester),
C. B. Markwardt (NASA/GSFC), S. R. Oates (UCL-MSSL),
C. Pagani (U Leicester), K. L. Page (U Leicester),
D. M. Palmer (LANL), A. Rowlinson (U Leicester),
C. J. Saxton (UCL-MSSL) and M. H. Siegel (PSU) report on behalf of the
Swift Team:

At 06:09:11 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 110719A (trigger=457553).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 24.564, +34.572 which is 
   RA(J2000) = 01h 38m 15s
   Dec(J2000) = +34d 34' 20"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a single noisy
FRED structure with a duration of about 50 sec.  The peak count rate
was ~1000 counts/sec (15-350 keV), at ~T-1 sec after the trigger. 

The XRT began observing the field at 06:11:03.1 UT, 111.3 seconds after
the BAT trigger. XRT found a bright, uncatalogued X-ray source located
at RA, Dec 24.5799, +34.5869 which is equivalent to:
   RA(J2000)  = 01h 38m 19.17s
   Dec(J2000) = +34d 35' 12.8"
with an uncertainty of 5.6 arcseconds (radius, 90% containment). This
location is 71 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 121 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
0.04. 

Burst Advocate for this burst is T. Sakamoto (Taka.Sakamoto 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.)