//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 11440 SUBJECT: GRB 101204A detected in ground analysis of BAT data DATE: 10/12/06 02:55:20 GMT FROM: Jay R. Cummings at NASA/GSFC/Swift J. R. Cummings (GSFC/UMBC/CRESST) on behalf of the Swift-BAT team At 23:53:29 UTC on December 4, 2010 Swift-BAT detected GRB 101204A (BAT trigger # 439806). No source was detected onboard. An automated script on the ground detected a source at RA, Dec 167.548, -20.434, which is RA (J2000) 11h 10m 11.6s Dec (J2000) -20d 26m 04s The source was 3.5% coded. As seen by BAT, the burst was a single gradual pulse about 10 seconds long. In the 10-second interval for which we have detailed event data, which covers almost all of the burst, the spectrum is best fitted by a simple power law with a photon index of 1.3 +- 0.2. The fluence from 15 to 150 keV was 1.2 +- 0.4 x 10^-6 erg/cm^2. The spectrum may be slightly distorted by edge of FOV effects, tending to reduce the number of lower-energy photons detected relative to higher-energy photons. A Swift TOO has been requested. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 11442 SUBJECT: GRB 101204A Swift-XRT/UVOT afterglow candidate DATE: 10/12/06 19:22:04 GMT FROM: Boris Sbarufatti at INAF-OAB/IASFPA B. Sbarufatti (INAF-OAB/IASFPA), S. Oates (MSSL) report on behalf of the Swift-XRT and Swift-UVOT teams We have analysed 4.9 ks of XRT data for GRB 101204A (Cummings et al. GCN Circ. 11440), from 126.2 ks to 134.4 ks after the BAT trigger. The data are entirely in Photon Counting (PC) mode. Using 4956 s of PC mode data and 2 UVOT images, we find an enhanced XRT position (using the XRT-UVOT alignment and matching UVOT field sources to the USNO-B1 catalogue): RA, Dec = 167.53712, -20.41924 which is equivalent to: RA (J2000): 11h 10m 08.91s Dec(J2000): -20d 25' 09.2" with an uncertainty of 2.3 arcsec (radius, 90% confidence). The source is detected at a level of 2.0+/-0.2E-3 counts/s, corresponding to a 0.3-10 keV flux of 1.4E-12 erg cm-2 s-1. At this time we are not able to tell if the source is fading. The Swift/UVOT began settled observations of the field of GRB 101204A 126199 s after the BAT trigger (Cummings et al., GCN Circ. 11440). An uncatalogued source is found at the UVOT position RA(J2000)= 167.53683 deg, DEC(J2000) = -20.42014, which is: RA (J2000) = 11:10:08.84 Dec (J2000) = -20:25:12.5 with an estimated uncertainty of 0.6 arcsec (radius, 90% confidence). This position is consistent with the XRT candidate position. At this time we are not able to tell if this source is fading. Preliminary magnitudes using the UVOT photometric system(Poole et al. 2008, MNRAS, 383, 627) for the initial exposures are: Filter T_start(s) T_stop(s) Exp(s) Mag ##################################################### v 126194 127496 1281 20.28 +/- 0.24 v 131976 133278 1281 20.71 +/- 0.34 u 127505 128780 1255 19.79 +/- 0.13 u 133286 134378 1074 19.91 +/- 0.15 ##################################################### The values quoted above are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.03 in the direction of the burst (Schlegel et al. 1998). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 11444 SUBJECT: GRB 101204A Afterglow Candidate, VATT Observations DATE: 10/12/07 03:48:56 GMT FROM: Peter Garnavich at U of Notre Dame P. Garnavich and J. Pagnini (Notre Dame) report: We observed field of GRB 101204A beginning on Dec. 6.51 (UT) with the Vatican Advanced Technology Telescope (VATT) and VATT4K CCD camera. The imaging was centered on the original BAT position (Cummings, GCN 11440) and were obtained 1.52 days after the burst. Six R-band images were taken in poor conditions. The optical afterglow candidate identified by Swift-UVOT (Sbarufatti et al., GCN 11442) is detected in the VATT images. The deepest images centered on Dec. 6.521 give R=20.0+/-0.1 mag calibrated from the USNO B1.0 star at 11:10:13.908 -20:26:07.8 with R2=17.74 mag. The observations span less than 20 minutes so it is not possible to determine if the source is fading. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 11445 SUBJECT: GRB101204A GROND Detection of the Optical/NIR Afterglow DATE: 10/12/07 21:22:30 GMT FROM: Robert Filgas at MPI A. Nicuesa Guelbenzu (Tautenburg Obs.), R. Filgas, J. Greiner and P. Schady (all MPE Garching) report on behalf of the GROND team: We observed the field of GRB 101204A (Swift trigger 439806; Cummings, GCN #11440) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008, PASP 120, 405) mounted at the 2.2 m MPI/ESO telescope at La Silla Observatory (Chile). Observations started at 05:55 UT on December 7, 2.2 days after the GRB trigger,and ended at 08:36 UT. They were performed at an average seeing of 1.2" and at an average airmass of 1.5. We confirm the afterglow candidate reported by Sbarufatti et al.(GCN #11442). After calibrating against the comparison star from Garnavich et al.(GCN #11444), we find the afterglow candidate to have faded by at least 0.6 mag in the time between the VATT (Garnavich et al.) and GROND observations. We also find the SED of this source to be well-fit by a power-law, providing further evidence of this being the afterglow of GRB101204A. Based on the best 7.7 min of total exposures in g'r'i'z' and 8 min in JHK taken at 08:18 UT, we estimate preliminary magnitudes (all in AB) of g' = 21.3 +- 0.1 mag, r' = 21.0 +- 0.1 mag, i' = 20.8 +- 0.1 mag, z' = 20.5 +- 0.1 mag, J = 20.3 +- 0.1 mag and H = 19.6 +- 0.1 mag Given magnitudes are calibrated against GROND zeropoints as well as 2MASS field stars and are not corrected for the expected Galactic foreground extinction corresponding to a reddening of E_(B-V)=0.033 mag in the direction of the burst (Schlegel et al. 1998). We thank the ESO staff at LaSilla observatory, and in particular A. Sanchez, for their excellent support and assistance with the observations. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 11446 SUBJECT: GRB 101204A: Swift-XRT refined Analysis DATE: 10/12/09 16:38:18 GMT FROM: Boris Sbarufatti at INAF-OAB/IASFPA B. Sbarufatti (INAF/OAB-IASF Pa) reports on behalf of the Swift-XRT team: We have analysed 24 ks of XRT data for GRB 101204A (Cummings et al. GCN Circ. 11440), from 126.2 ks to 383.1 ks after the BAT trigger. The data are entirely in Photon Counting (PC) mode. Using 9912 s of PC mode data and 4 UVOT images, we find an enhanced XRT position (using the XRT-UVOT alignment and matching UVOT field sources to the USNO-B1 catalogue): RA, Dec = 167.53700, -20.41980 which is equivalent to: RA (J2000): 11h 10m 8.88s Dec(J2000): -20d 25' 11.5" with an uncertainty of 1.6 arcsec (radius, 90% confidence). The light curve can be modelled with a power-law decay with a decay index of alpha=1.33 (+0.24, -0.23). A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 2.14 (+0.34, -0.18). The best-fitting absorption column is consistent with the Galactic value of 3.3 x 10^20 cm^-2 (Kalberla et al. 2005). The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 3.4 x 10^-11 (3.9 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 3.3 (+4.4, -0.0) x 10^20 cm^-2 Galactic foreground: 3.3 x 10^20 cm^-2 Excess significance: <1.6 sigma Photon index: 2.14 (+0.34, -0.18) The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00020153. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 11447 SUBJECT: GRB101204A: Swift/UVOT observations DATE: 10/12/09 19:11:39 GMT FROM: Samantha Oates at MSSL S. R. Oates (MSSL-UCL) & B. Sbarufatti (INAF-OAB/IASFPA) report on behalf of the Swift-XRT and Swift-UVOT teams The Swift/UVOT began settled observations of the field of GRB 101204A 126195 s after the BAT trigger (Cummings et al., GCN Circ. 11440). In agreement with report from Nicuesa Guelbenzu et al., (GCN Circ. 11445), we find the afterglow candidate in (Sbarufatti et al. GCN Circ. 11442) to have faded. Preliminary magnitudes using the UVOT photometric system (Poole et al. 2008, MNRAS, 383, 627) for summed exposures are: Filter T_start(s) T_stop(s) Exp(s) Mag ##################################################### v 126195 133279 2563 20.51 +/- 0.19 v 271960 336155 3553 > 21.62 u 127505 134378 2329 20.03 +/- 0.12 u 272471 336626 3273 21.27 +/- 0.26 ##################################################### The values quoted above are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.03 in the direction of the burst (Schlegel et al. 1998).