////////////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6182 SUBJECT: GRB 070309: A long GRB detected by INTEGRAL DATE: 07/03/09 11:42:41 GMT FROM: Sandro Mereghetti at IASF/CNR A.Paizis, S.Mereghetti (IASF-Milano), D.Gotz (CEA-Saclay), I.Kreykenbohm, N.Mowlavi, M. Beck (ISDC, Versoix), and J. Borkowski (CAMK, Torun) on behalf of the IBAS Localization Team report: A GRB lasting about 40 s has been detected by IBAS in IBIS/ISGRI data on March 9 at 10:01:03 UT The coordinates (J2000) are: RA: 263.6848 [degrees] DEC: -37.9446 [degrees] with an uncertainty of 2.5 arcmin (90% c.l.). Preliminary analysis of the IBIS data indicates a peak flux of 0.2 photons/cmq s (20-200 keV, 1 s integration time) and a fluence of 5x10e-7 erg/cmq A plot of the light curve will be posted at http://ibas.mi.iasf.cnr.it/IBAS_Results.html This message can be cited. ////////////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6183 SUBJECT: Swift UVOT Finding Charts for GRB 070309 DATE: 07/03/09 16:01:47 GMT FROM: Pete Roming at PSU P. Roming (PSU) reporting on behalf of the Swift UVOT team: The Swift UVOT team is currently uploading enhancements to the UVOT software. Due to the fact that the code load has not been completed, the UVOT generated finding charts in all the UVOT color filters for GRB 070309 (GCN 6182). Although this is not normal operating procedure for the UVOT, we want to make the community aware that the finding charts are valid data for the field of the GRB. We apologize for any confusion the code load has created. ////////////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6185 SUBJECT: GRB 070309: Swift/UVOT Upper Limits DATE: 07/03/09 20:54:28 GMT FROM: Stephen Holland at USRA/NASA/GSFC/SSC S. T. Holland (CRESST/USRA/GSFC) and Cucchiara A. (PSU) report on the behalf of the Swift UVOT team: Swift/UVOT observed the field of GRB 070309 (Paizis, et al. 2007, GCN Circ. 6182) starting 13,906 s after the INTEGRAL/IBAS trigger. UVOT did not detect any source inside the INTEGRAL error circle, relative to the DSS, down to the following 3 sigma upper limits. Filter t_start(s) t_stop(s) Exp(s) Mag 3-sig UL V 14,525 14,868 274 19.3 B 14,215 14,365 147 20.0 U 14,061 14,211 147 19.7 UVW1 13,906 14,056 147 19.6 UVM2 14,930 15,080 147 19.5 UVW2 14,371 14,446 147 19.8 These upper limits are not corrected for the Galactic extinction, corresponding to a reddening of E_{B-V} = 1.46 mag (Schlegel et al. 1998), in the direction of this burst. We note that this burst lies in the Galactic plane towards the Galactic centre and the field is very crowded. ////////////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6187 SUBJECT: GRB070309: Swift/XRT possible afterglow detection DATE: 07/03/10 00:14:35 GMT FROM: Pat Romano at OAB-Swift S.D. Vergani (Dunsink observatory-DIAS, DCU), P. Romano (INAF-OAB, Univ. Bicocca), C. Guidorzi (INAF-OAB, Univ. Bicocca) report on behalf of the Swift-XRT team: We have analyzed the Swift XRT data from the first 11ks observations of INTEGRAL GRB 070309 (Paizis, et al. 2007, GCN Circ. 6182). Inside the INTEGRAL error circle we find one source at the position RA(J2000) = 17h 34m 39.1s Dec(J2000) = -37d 55' 48.2" with an estimated error radius of ~5 arcsec (90% confidence). This is 81 arcseconds from the INTEGRAL position. The source has a count rate of (2.0+-0.6)E-3 counts/s and, assuming a crab spectrum, a flux of 5E-14 erg/cm2/s. We collected a total of 15 counts. More data are being collected that will be used to determine whether the source is fading and to perform a spectral analysis. This Circular is an official product of the Swift XRT Team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6187 SUBJECT: GRB070309: Swift/XRT possible afterglow detection DATE: 07/03/10 00:14:35 GMT FROM: Pat Romano at OAB-Swift S.D. Vergani (Dunsink observatory-DIAS, DCU), P. Romano (INAF-OAB, Univ. Bicocca), C. Guidorzi (INAF-OAB, Univ. Bicocca) report on behalf of the Swift-XRT team: We have analyzed the Swift XRT data from the first 11ks observations of INTEGRAL GRB 070309 (Paizis, et al. 2007, GCN Circ. 6182). Inside the INTEGRAL error circle we find one source at the position RA(J2000) = 17h 34m 39.1s Dec(J2000) = -37d 55' 48.2" with an estimated error radius of ~5 arcsec (90% confidence). This is 81 arcseconds from the INTEGRAL position. The source has a count rate of (2.0+-0.6)E-3 counts/s and, assuming a crab spectrum, a flux of 5E-14 erg/cm2/s. We collected a total of 15 counts. More data are being collected that will be used to determine whether the source is fading and to perform a spectral analysis. This Circular is an official product of the Swift XRT Team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6200 SUBJECT: GRB 070309: variability of the XRT afterglow candidate DATE: 07/03/12 17:02:35 GMT FROM: Cristiano Guidorzi at INAF-OAB S.D. Vergani (Dunsink observatory-DIAS, DCU), P. Romano (INAF-OAB, Univ. Bicocca), C. Guidorzi (INAF-OAB, Univ. Bicocca), A. Moretti (INAF-OAB) report on behalf of the Swift-XRT team: We continued to analyse the XRT data regarding the source reported by Vergani et al. in GCN Circ. 6187. We collected a total of 21 counts for a total exposure time of about 17ks. It is not possible to extract a proper light curve or spectrum. We divided the observations in two consecutive blocks, with exposures of 7672 s and of 9623 s, collecting 16 and 5 counts, respectively. In the assumption of a constant rate source, the probability of having equally or less uniformly distributed counts is estimated to be smaller than 1%. We conclude that this seems to be a varying source but at the present time we cannot confirm that this is the X-ray afterglow of GRB070309. This Circular is an official product of the Swift XRT Team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6369 SUBJECT: GRB 070309: Swift-XRT afterglow confirmation DATE: 07/04/30 18:16:34 GMT FROM: Pat Romano at OAB-Swift S.D. Vergani (Dunsink observatory-DIAS, DCU), P. Romano (INAF-OAB, Univ. Bicocca), C. Guidorzi (INAF-OAB, Univ. Bicocca) report on behalf of the Swift-XRT team: XRT observed again the field of INTEGRAL GRB 070309 (Paizis, et al. 2007, GCN Circ. 6182) between 26 and 27 April (about 50 days after the trigger) for a total exposure time of about 17ks to verify the nature of the afterglow candidate reported by Vergani et al. in GCN Circ.'s 6187 and 6200. There is no source detected at the afterglow candidate position (RA(J2000) = 17h 34m 39.1s Dec(J2000) = -37d 55' 48.2") down to a count rate of 1.43E-3 counts/s (3 sigma). We therefore confirm that the candidate suggested in GCN Circ. 6187 is the afterglow of GRB 070309. This Circular is an official product of the Swift XRT Team.