GRB 070714, GRB 070714A

S.D. Barthelmy (GSFC)
on behalf of the Swift-BAT team:

It has been noted by several people (D. Grupe, M. Chester, and F. Marshall)
that the T_zero trigger time for GRB 070714A (Grupe, et al., 6619;
Barthelmy et al., 6622) is missing from the standard set of communications
on this burst.  Normally T_zero is published in the Notices and the
"first Swift Circular" on the burst.  But because all the TDRSS messages
were lost due to a TDRSS outage, we dropped the ball on this in the later
circular.

The trigger time for GRB 070714A (trigger 284850) is 03:20:30.618 UT.

M.M. Chester (PSU) and D. Grupe (PSU) report on the behalf of the
Swift UVOT team:

The Swift/UVOT observed the field of GRB070714A (trigger=284850)
starting 2007-195-03:21:15, 44 s after the BAT trigger (Grupe et al.
2007, GCN Circ. 6619
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 ). We do not find any new source in any of the UVOT
observations inside the refined XRT error circle (Grupe 2007, GCN Circ.
6628
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 ).

The 3-sigma upper limits for detecting a source inside the XRT error
circle in the first finding chart (FC) exposure and the co-added frames
(including the finding chart) are:

Filter   Tstart   Tstop    Exp     Magnitude
            (s)     (s)     (s)    (3-sigma UL)
White FC    61     161      98.2     20.19
White       61    1641     235       20.63
v           44    1690     855       19.69
b          647    5955     138       19.55
u          622    5868     274       19.71
uvw1       598    5664     274       19.03
uvm2      5258    5458     197       18.96
uvw2       677    1666      77.8     18.49

The values quoted above are not corrected for the expected Galactic
extinction corresponding to a reddening of E_{B-V} = 0.186 mag in the
direction of the burst (Schlegel et al. 1998).

D.Grupe (PSU) reports on behalf of the Swift/XRT team:


I analyzed the first (and only) orbit of X-ray data of GRB 070714A (BAT 
trigger
284850; Grupe et al. GCN 6619
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 ) with a total exposure time of 2.3 ks.
The XRT began observing the field of GRB 070714A at 2007-07-14 03:21:25 UT,
54.4 seconds after the BAT trigger.
Using 799 s of overlapping XRT Photon Counting (PC) mode and UVOT V-band
data, 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 =
42.93073, 30.24339 which is equivalent to:

RA (J2000):  02 51 43.37
Dec (J2000): +30 14 36.2

with an uncertainty of 2.0"  (90% confidence radius).


The XRT PC mode light curve shows a fading afterglow with a decay slope of
1.02+\-0.29. The predicted count rate (flux) 24 hours after the burst is 
1.5e-3
counts s-1 (1.4e-13 ergs s-1 cm-2) and 7.3e-4 counts s-1 (6.8e-14 ergs s-1
cm-2) at 48 hours after the trigger.

The X-ray spectrum can be fitted by a single absorbed power law with the
absorption column density in agreement with the Galactic value (NH=9.24e20
cm-2; Dickey & Lockman 1990) and a Photon spectra index Gamma = 
1.68+\-0.23.


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

P. Nugent (LBL) and J. S. Bloom (UC Berkeley) report:

We have created a stacked image through the co-addition of 8  
unfiltered images taken by the NEAT collaboration and 51 images in  
the RG610 filter taken by the Palomar-Quest Consortium at the Palomar  
Oschin Schmidt telescope (obtained from 2002-2006), of what is being  
called a short-hard burst (SHB) 070714A (Barbier et al.; GCN #6622
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 ).  
The stacked image is significantly deeper than the DSS (3 sigma limit  
of R~22.7 mag). There is no source at the position of the proposed  
counterpart (Melandri et al. GCN #6621
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 ). Since this Liverpool  
Telescope source was detected in twilight, it was likely seen near  
the DSS limit (or brighter) and thus, while we cannot say for sure  
(since no magnitude was given in GCN #6621
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 ), the absence of a  
similarly bright source in our image suggests that the Melandri et  
al. source was indeed the afterglow.

Note that the source @ position RA = 03:51:21.24, DEC = +28:17:45.5  
is in the 2MASS catalog and is blue (J - K = 0.5 mag).

This message may be cited.

S.D. Barthelmy (GSFC), L. Barbier (GSFC), J. Cummings (GSFC/UMBC),
E. Fenimore (LANL), N. Gehrels (GSFC), D. Grupe (PSU),
H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD), D. Palmer (LANL),
A. Parsons (GSFC), T. Sakamoto (GSFC/ORAU), G. Sato (GSFC/ISAS),
M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC), T. Ukwatta (GWU)
(i.e. the Swift-BAT team):

Using the data set from T-240 to T+962 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 070714A (trigger #284850)
(Grupe, et al., GCN Circ. 6619
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 ).  The BAT ground-calculated position is
RA, Dec = 42.933, 30.241 deg  which is
   RA(J2000)  =  2h 51m 43.8s
   Dec(J2000) = 30d 14' 28"
with an uncertainty of 1.3 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 96%.

The mask-weight lightcurve shows a single peak starting at T+0, peaking at
T+0.7, and ending at T+2 sec, where the rise time is a little faster than
the decay.  T90 (15-350 keV) is 2.0 +- 0.3 sec (estimated error including
systematics).

The time-averaged spectrum from T-0.7 to T+2.3 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
2.6 +- 0.2.  The fluence in the 15-150 keV band is 1.5 +- 0.2 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T+0.30 sec in the 15-150 keV band
is 1.8 +- 0.2 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level.

We note that the fluence ratio in a simple power-law fit between the
25-50 keV band and the 50-100 keV band is 1.52.  This fluence ratio is larger
than 1.32, which can be achieved in the Band function of alpha=-1.0, beta=-2.5,
and Epeak=30 keV.  Thus, preliminary analysis shows that Epeak of the burst
is very likely around or below 30 keV.  Therefore the burst can be classified
as an X-ray flash.

A. Melandri (Liverpool JMU) on behalf of the Liverpool GRB
team report:


On 2007 Jul 14 at 05:10:56 UT the 2-m Liverpool Telescope
automatically observed the field of GRB 070714 (trigger=284856,
Racusin et al. GCN 6620
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 ).

Due to the incoming dawn the automatic observation sequence stopped
after ~15 minutes, after the acquisition of only 9 frames.

Inside the XRT error circle (Racusin et al. GCN 6620
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 ) we find a
single source at the position (error of 0.5 arcsec)

RA = 03:51:22.2
Dec = +28:17:51.4

It is not a catalog source but presently it's not clear yet whether
the object is fading.

J. L. Racusin (PSU), S. D. Barthelmy (GSFC), D. N. Burrows (PSU),
M. M. Chester (PSU), N. Gehrels (NASA/GSFC), H. A. Krimm (GSFC/USRA),
D. M. Palmer (LANL) and T. Sakamoto (NASA/ORAU) report on behalf of
the Swift Team:

At 04:59:29 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 070714 (trigger=284856).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 57.854, +28.295 which is 
   RA(J2000)  =  03h 51m 25s
   Dec(J2000) = +28d 17' 43"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve shows a duration of
3 seconds with a spike to a peak of 20000 counts/s (15-350 keV) 
at T+0.2 s. 

The XRT began observing the field at 05:00:30 UT, 61 seconds after the
BAT trigger. Using ground processed data, XRT found a bright, fading, 
uncatalogued X-ray source located at RA, Dec 57.8423, +28.2978 which is
   RA(J2000)  =  03h 51m 22.1s
   Dec(J2000) =  28d 17' 52.0"
with an uncertainty of 3.9 arcseconds (radius, 90% containment). 
This location is 39 arcseconds from the BAT on-board position,
within the BAT error circle. The initial flux in the 2.5s image
was 2.4e-09 erg/cm2/s (0.2-10 keV). 

The UVOT began observing the field at 05:00:40.05 UT, 70.4 s after the
BAT trigger. No counterpart is apparent in the 2.7' x 2.7' subimage,
based on visual comparison with the DSS. Additional processing is
underway. 

Burst Advocate for this burst is J. L. Racusin (racusin AT astro.psu.edu). 
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.)