GRB 080922

S.Mereghetti, A.Paizis (IASF-Milano), D.Gotz (CEA-Saclay), W. Ishibashi, 
V.Beckmann, M. Beck (ISDC, Versoix), and J. Borkowski (CAMK, Torun) on 
behalf of the IBAS Localization Team report:

A GRB lasting about 60 s has been detected by IBAS in IBIS/ISGRI data at 
11:03:36 UT of September 22. The coordinates (J2000)  are:

RA: 270.838 [degrees]
DEC: -22.509 [degrees]

with an uncertainty of 2 arcmin (90% c.l.).

A preliminary analysis gives a peak flux in the 20-200 keV range of about 
1 ph/cmq/s (1-s integration time) and a fluence over the same energy 
range of about 1.5x10e-6 erg/cmq.

A plot of the light curve will be posted at

http://ibas.iasf-milano.inaf.it/IBAS_Results.html

This message can be cited.

B. Sbarufatti, V. La Parola, V. Mangano (INAF-IASFPa), on behalf of the Swift-XRT team

  At 2008-09-22 14:54UT Swift performed a TOO observation of the INTEGRAL
burst GRB 080922 (Mereghetti et al., GCN Circ. 8281
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 ), 3h52m after the
INTEGRAL trigger.

   No X-ray source was found in or near the IBAS error circle in a 5.9ks
exposure Swift/XRT Photon Counting mode image down to a 3 sigma limiting 0.3-10keV count
rate of 4.3e-3 count/s. Assuming a power-law spectrum of photon index 2
absorbed by the Galactic column density of 1.14e22 cm-2 in the direction
of the burst, this corresponds to an observed 0.3-10keV flux limit of
2.55e-13 erg cm-2 s-1.

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

S. T. Holland (CRESST/GSFC/USRA) and B. Sbarufatti (INAF-IASFPa)
report on the behalf of the Swift UVOT team:

      The Swift/UVOT observed the field of GRB 080922 starting 13,904 s
(= 3.84 hr) after the INTEGRAL detection (Mereghetti et al. 2008, GCN
Circ. 8281
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 ).  We do not find any new source, relative to the DSS or
2MASS, or any variable source inside the INTEGRAL/IBAS error circle.
The 3-sigma upper limits for detecting a source in the co-added
images, using a 2.5 arcsecond radius circular aperture, are:

Filter  T_start   T_stop   Exp(s)     Mag
-----------------------------------------
    v     15,622   15,834     208    >18.9
    b     14,550   26,731     625    >20.6
    u     14,333   31,298     834    >20.3
  uvw1    13,904   30,081    1668    >20.5
  uvm2    15,839   15,853      14    >16.1
  uvw2    14,769   27,419    2341    >20.8
-----------------------------------------

The quoted upper limits have not been corrected for the expected, and
highly uncertain, Galactic extinction along the line of sight
corresponding to a reddening of E_{B-V} = 20 mag (Schlegel, et al.,
1998, ApJS, 500, 525).  All photometry is on the UVOT flight system
described in Poole et al. (2008, MNRAS, 383, 627).

R. Hara, H.hayasi, N.Ohmori, K.Kono H. Tanaka, M.Yamauchi, E.Sonoda,
(University of Miyazaki)

We have observed the field covering the error circle of
GRB080922 (GCN 8281
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 , S.Mereghetti et al.) with
the unfiltered CCD camera on the 30-cm telescope at
University of Miyazaki.
The observation was started 11:14:04 UT, 11.7min
after the INTEGRAL trigger time.

We have compared our data of 30 sec exposures
with the USNO-A2.0 catalog,there is no new source
at the reported position.

the upper limits are as follows:
--------------------------------------------------------------
Start(UT) End(UT) Num. of frames Limit (mag.)
--------------------------------------------------------------
11:15:19  11:15:49      1        16.7
11:15:19  11:41:35      20       17.1
---------------------------------------------------------------

-- 
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ryuu55@astro.miyazaki-u.ac.jp
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