GRB 070615
GCN Circular 6537
Subject
GRB 070615: A long GRB detected by INTEGRAL
Date
2007-06-15T03:18:15Z (18 years ago)
From
Sandro Mereghetti at IASF/CNR <sandro@iasf-milano.inaf.it>
S.Mereghetti, A.Paizis (IASF-Milano), D.Gotz (CEA-Saclay), V.Beckmmann, M.
Beck, C.Steiner (ISDC, Versoix), and J. Borkowski (CAMK, Torun) on behalf
of the IBAS Localization Team report:
A GRB lasting about 30 s has been detected by IBAS in IBIS/ISGRI data on
June 15 at 02:20:45 UT
The coordinates (J2000) are:
RA: 44.307736 [degrees]
DEC: -4.407888 [degrees]
with an uncertainty of 2 arcmin (90% c.l.).
The light curve is a single, FRED-like peak
This message can be cited.
GCN Circular 6538
Subject
GRB 070615
Date
2007-06-15T10:30:56Z (18 years ago)
From
John French at UCD,Ireland <jfrench@bermuda.ucd.ie>
John French (University College Dublin), Petr Kubanek (GACE Valencia),
Gary Melady (University College Dublin), Martin Jelinek IAA CSIC
Granada)
report on behalf of the Watcher collaboration:
The Watcher 40cm robotic telescope, located at Boyden Observatory,
South Africa, began imaging the field of INTEGRAL GRB 070615
(Mereghetti et al., GCN 6537) at 02:22:08 UT, 1m22s after the IBAS
trigger.
Initial observations were performed at high airmass and show no new
source down to an R-band limiting magnitude of approximately 15 (in
comparison with USNO-B1). Observations and analysis are ongoing.
This message may be cited.
GCN Circular 6540
Subject
UVOT Observations of INTEGRAL burst GRB070615
Date
2007-06-16T08:12:52Z (18 years ago)
From
Patricia Schady at MSSL/Swift <ps@mssl.ucl.ac.uk>
P.Schady (MSSL-UCL) and N. Lyons (Leicster) report on behalf of the
UVOT team
Swift/UVOT began observing the field of the INTEGRAL burst GRB070615
10.7hrs after the IBAS trigger in the V and white filters. No afterglow
is detected in any of the individual or co-added observations down to
the following 5-sigma upper limits:
Filter T_mid (s) Exp (s) UL Mag (5sig)
====================================
V 46354 2887 19.59
White 51435 36 18.07
====================================
where T_mid corresponds to weighted mid time of the observation. The
values quoted above are not corrected for the expected Galactic
reddening of E(B-V) = 0.12 mag (Schlegel et al. 1998).
GCN Circular 6544
Subject
Swift XRT observations of the INTEGRAL burst GRB070615: Possible
Date
2007-06-16T20:55:10Z (18 years ago)
From
Olivier Godet at U.of Leicester <og19@star.le.ac.uk>
O. Godet, N. Lyons, K.L. Page, P.A. Evans, J. Osborne, R. Starling
(U. Leicester) and G. Tagliaferri (INAF-OAB) report on behalf the
Swift-XRT team:
The XRT started to observe the field of the INTEGRAL burst GRB 070615
(Mereghetti et al., GCN 6537) 10.7h after the IBAS trigger. We analysed
around 3ks of PC data. A possible weak and uncatalogued X-ray source is
detected at a position of:
RA(J2000) = 02h 57m 15.37s
Dec(J2000) = -04d 24' 26.6"
with an uncertainty of 7.5 arcsec (90% containment radius). This is 23
arcsec from the INTEGRAL position given by Mereghetti et al. (GCN Circ.
6537).
We note that there are only 5 counts detected in the error circle
centred on this position. In this region, only ~0.07 background counts
would be expected. Using the Bayesian method to find a 99.7\% level
confidence limit on the actual number of counts from the source, the
range would then be between 0.8 and 14.9 counts. We estimate the
probability that this detection is due to a background fluctuation to be
6e-7, suggesting that this is a real detection.
Since it is impossible to say whether or not the source is fading, we
cannot say with any certainty that the source is the X-ray afterglow of
GRB 070615.
This circular is an official product of the Swift-XRT team.
GCN Circular 6580
Subject
INTEGRAL burst GRB070615: X-ray continued observations
Date
2007-06-26T15:01:42Z (18 years ago)
From
Olivier Godet at U.of Leicester <og19@star.le.ac.uk>
O. Godet, N. Lyons, K.L. Page, A.P. Beardmore (U. Leicester) report on
behalf the Swift-XRT team:
In Godet et al. (GCN Circ. 6544), we reported the detection of a faint
and uncatalogued X-ray source after analysing 3ks of Swift PC data taken
10.7h after the IBAS trigger (Mereghetti et al., GCN Circ. 6537). We
estimated the source count rate to be between 5.5e-4 c/s and 3.6e-3 c/s
at a 95% confidence level using the Bayesian method. However, it was
impossible to say whether or not the source was fading due to the limited
statistics.
We analysed 8.5ks of additional PC data taken 6.9 days after the IBAS
trigger and no counts were found inside the 7.5 arcsec radius error
circle. In this region, only 0.1 background counts would be expected.
Using the Bayesian method, we estimated the upper limit on the count
rate to be around 3.5e-4 c/s at a 95% confidence level.
So, the weak X-ray source may be fading.
This is an official product of the Swift XRT team.