GRB 060707

A. Moretti (INAF-OAB), S. D. Barthelmy (GSFC), P. T. Boyd (NASA/GSFC),
P. J. Brown (PSU), M. M. Chester (PSU), N. Gehrels (NASA/GSFC),
C. Guidorzi (Univ Bicocca&INAF-OAB), J. A. Kennea (PSU),
C. B. Markwardt (GSFC/UMD), F. E. Marshall (NASA/GSFC),
K. M. McLean (LANL/UTD), C. Pagani (PSU), D. M. Palmer (LANL),
T. Sakamoto (NASA/ORAU), M. Stamatikos (NASA/ORAU) and
D. E. Vanden Berk (PSU) report on behalf of the Swift Team:

At 21:30:19 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 060707 (trigger=217704).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA,Dec 357.079, -17.923 {23h 48m 19s, -17d 55' 21"} (J2000)
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve shows a single FRED-like peak
at T_0 lasting about 30 sec.  There is a hard precusor at T-45 sec. 
The total duration is ~75 sec.  The peak count rate
was ~1500 counts/sec (15-350 keV), at ~2 sec after the trigger. 

The XRT began taking data at 21:32:20 UT, 122 seconds after the BAT
trigger.  The XRT on-board centroid algorithm did not find a source in the
image and no prompt position is available.  Down-linked
data show a bright source at RA(2000)=23 48 19.00  DEC(2000):-17 54 21.8
with an error circle of 3.8". This position is 60" from the BAT position. 

UVOT took a finding chart exposure of 100 seconds with the White
(160-650 nm) filter starting 126 seconds after the BAT trigger. No
afterglow candidate has been found in the initial data products. The
2.7'x2.7' sub-image covers 25% of the BAT error circle and 100% of
the ground-determined 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 BAT 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.

A. de Ugarte Postigo, J. Gorosabel and A.J.Castro-Tirado (IAA-CSIC)
on behalf of the BOOTES-IR Collaboration.

"The BOOTES-IR 0.6m telescope, located at IAA-CSIC Observatorio 
de Sierra  Nevada in Granada (Spain), observed the SWIFT error 
box for GRB 060707 (Moretti et al. GCNC 5285). R-band observations
started at 01:20 UT(3:50 h after the burst, when it became 
observable from our location). A limiting R-band magnitude of ~20 
is derived for the afteglow at ~ 1:45 UT.

This message is quotable".

M. Stamatikos (GSFC/ORAU), L. Barbier (GSFC), S. Barthelmy (GSFC),
J. Cummings (GSFC/ORAU), E. Fenimore (LANL), N. Gehrels (GSFC),
D. Hullinger (BYU-Idaho), H. Krimm (GSFC/USRA), M. Koss (GSFC/UMD),
C. Markwardt (GSFC/UMD), D. Palmer (LANL), A. Parsons (GSFC),
T. Sakamoto (GSFC/ORAU), G. Sato (GSFC/ISAS), J. Tueller (GSFC)
on behalf of the Swift-BAT team:

Using the data set from T-120 to T+182 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 060707 (trigger #217704)
(Moretti, et al., GCN 5285
Loading...
 
 ).  The BAT ground-calculated position is RA,Dec =
357.073, -17.908 deg {23h 48m 17.4s, -17d 54' 27.4"} (J2000) +- 1.5 arcmin,
(radius, sys+stat, 90% containment).  The partial coding was 43%.
 
The mask-tagged lightcurve consists of two peaks.  The first starts at T-50 sec,
peaks at ~T-40 and then returns to a minumum at T-18 sec where it start to rise
for the beginning of the second peak.  The second peaks at ~T+5sec and ends
at ~T+40 sec.  There is no apparent further emission out to T+1400 sec.
T90 (15-350 keV) is 68 +- 5 sec (estimated error including systematics).
 
The time-averaged spectrum from T-50 to T+25 is best fit by a power law
with an exponential cutoff.  This fit gives a photon index 0.66 +- 0.63, 
and Epeak of 66 (-10/+25) keV (chi squared 64.0 for 56 d.o.f.).  
For this model the total fluence in the 15-150 keV band is
1.7 +- 0.2 x 10^-6 erg/cm2 and the 1-sec peak flux measured from T+3.05 sec
in the 15-150 keV band is 1.1 +- 0.2 ph/cm2/sec.  A fit to a simple power law
gives a photon index of 1.68 +- 0.13 (chi squared 73.4 for 57 d.o.f.).
All the quoted errors are at the 90% confidence level.

A. de Ugarte Postigo, J.Gorosabel, M. Jelinek, R. Cunniffe,P. Kubanek,
S. Vitek, A. J. Castro-Tirado (IAA-CSIC Granada),P. Kubanek (ASU AV CR
Ondrejov & ISDC Versoix) and M. D. Sabau-Graziati (INTA Torrejon de
Ardoz, Madrid) report

Main text:
"The BOOTES-IR 0.6m telescope, located at IAA-CSIC Observatorio de
Sierra  Nevada in Granada (Spain), observed the SWIFT error box for 
GRB 060707 (Moretti et al. GCNC 5285).

Further analysis from the data of the night shows an object with 
R ~ 20.2 mag at coordinates R.A.= 23:48:19.00, Dec. = -17:54:17.0 
(J2000) with estimated uncertanity of 0.7 arcsec is present on 
the frames and not visible on the DSS2 comparison images. Futher
analysis are ongoing in order to check for variability and confirm 
its relationship to GRB 060707.

A finding chart will be soon available at:
www.iaa.es/~deugarte/GRBs/GRB060707/grb060707.gif

This message is quotable".

A. Stefanescu, F. Schrey, G. Kanbach, S. Duscha, M. M�hlegger, N.
Prymak, H. Steinle (MPE Munich) of the OPTIMA-Burst Team report the 
following:
"OPTIMA-Burst at the 1.3m Skinakas Observatory, located on Crete, Greece
observed the Swift XRT-Errorbox of GRB 060707 at 00:30 UT (3h after the
Burst).
We detected a faint source at the edge of the XRT-errorcircle (GCN
Circular #5285
Loading...
 
 ). We estimate the brightness of this source in a 10min
white-light image as 20.3+-.5mag. The position of the source is RA
23:48:19 Dec -17:54:18.4 (J2000). There is no source at this position in
the USNO-A2 Catalog, and no minor planet according to MPChecker.
  This source seems compatible with the source reported in GCN Circular 
5290
Loading...
 
 "

C. Guidorzi (Univ Bicocca & INAF-OAB), A. Moretti (INAF-OAB),
J. A. Kennea (PSU) on behalf of the Swift-XRT team:

We have analyzed the first two orbits of data of GRB060707
(Moretti et al 2006, GCN 5285
Loading...
 
 ).
The XRT data set consists of 43 s exposure in Windowed
Timing (WT) in the first orbit followed by 3.1 ks exposure
in Photon Counting (PC).

The refined position of the source is

   RA  (2000) =  23h 48m 18.89s  
   Dec (2000) = -17d 54' 20.4"

with an uncertainty of 3.9 arcsec (90% containment).

This position is 2.1 arcsec from the XRT position
first reported (Moretti et al 2006, GCN 5285
Loading...
 
 ),
3.7 arcsec from the IR optical afterglow candidate
position (de Ugarte-Postigo et al., GCN 5290
Loading...
 
 ) and
22.4 arcsec from the BAT ground-calculated position
(Stamatikos et al. 2006, GCN 5289
Loading...
 
 ).

The 0.3-10 keV X-ray light curve shows the typical
steep-to-shallow decay, with an initial power-law index
of alpha ~ 1.6, followed by alpha ~ 0.7, break time around 600s
from the BAT trigger time.

The PC spectrum is well fitted by an absorbed power law with
photon index 2.0 +/- 0.1 and N_H consistent with the Galactic value
(1.8e20 cm^-2). The average 0.3-10 keV unabsorbed flux during the
second orbit is 5.5e-12 erg cm^-2 s^-1.

Assuming alpha ~ 0.7, the extrapolated unabsorbed flux at 24 hours 
is 9e-13 erg cm^-2 s^-1.

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

Pall Jakobsson, Nial Tanvir (Univ. of Hertfordshire), Brian L. Jensen,
Johan P. U. Fynbo (DARK, NBI), Antonio de Ugarte Postigo, Javier
Gorosabel (IAA-CSIC Granada), Sylvio Klose (TLS Tautenburg) and Paul
Vreeswijk (ESO) report on behalf of a larger collaboration:

Using FORS1 on the Very Large Telescope, we have obtained 3*30 min
spectra (300V) of the GRB 060707 field (Moretti et al., GCN 5285
Loading...
 
 ). The
acquisition image shows that the proposed optical afterglow (de Ugarte
Postigo et al., GCN 5290
Loading...
 
 ) has faded by approximately two magnitudes.
Using photometric zeropoints from the ESO webpages we estimate the
afterglow magnitude to be R ~ 22.4 on July 9.329 (1.432 days post-burst).

The combined spectrum displays a strong absorption feature around
5386 AA, with the flux dropping substantially blueward of this feature.
Associating it with Ly-alpha gives a redshift of z = 3.43 for the burst.
At this redshift we find several other absorption features, including
Ly-beta, Si II, Si IV, C IV, Al II and O III].

A. Stefanescu, G. Kanbach, S. Duscha, F. Schrey, M. Muehlegger, N.
Prymak, H. Steinle (MPE Garching) of the OPTIMA-Burst Team report the
following:
"OPTIMA-Burst at the 1.3m Skinakas Observatory, of the University of 
Crete, Greece observed the Swift UVOT-Errorcircle of GRB 060714 at 
19:53UT (4:42h after the Burst).
We detected a faint source at the UVOT-Position (GCN
Circular #5311
Loading...
 
 ). We estimate the brightness of this source in a 10min
white-light image as 19.9+-.5mag. The position overlaps the UVOT 
errorcircle. There is no source at this position in
the USNO-A2 Catalog, and no minor planet according to MPChecker.

P. Chandra (UVA/NRAO) and  D. A. Frail (NRAO) report on behalf of the 
Caltech-NRAO-Carnegie GRB
Collaboration:

"We observed the field centered on the BAT position of the Swift burst GRB
060707 (GCN#5290
Loading...
 
 ) using the VLA at a frequency of 8.46 GHz and starting at
9.24 UT on Aug 20, about 45 days after the burst.  There is no detection 
of the GRB with
2-sigma upper limit of 82 microJy.

The National Radio Astronomy Observatory is a facility of the National
Science Foundation operated under cooperative agreement by Associated
Universities, Inc."