//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 10824 SUBJECT: GRB 100606A: Swift detection of a burst DATE: 10/06/06 19:23:43 GMT FROM: David Palmer at LANL S. R. Oates (UCL-MSSL), S. D. Barthelmy (GSFC), A. P. Beardmore (U Leicester), S. Campana (INAF-OAB), P. A. Curran (UCL-MSSL), P. A. Evans (U Leicester), N. Gehrels (NASA/GSFC), J. M. Gelbord (PSU), S. T. Holland (CRESST/USRA/GSFC), J. A. Kennea (PSU), H. A. Krimm (CRESST/GSFC/USRA), O. M. Littlejohns (U Leicester), C. B. Markwardt (CRESST/GSFC/UMD), P. T. O'Brien (U Leicester), K. L. Page (U Leicester), D. M. Palmer (LANL), P. Romano (INAF-IASFPA), A. Rowlinson (U Leicester), T. Sakamoto (NASA/UMBC), B. Sbarufatti (INAF-OAB/IASFPA), M. H. Siegel (PSU), R. L. C. Starling (U Leicester), E. Troja (NASA/GSFC/ORAU), T. N. Ukwatta (GSFC/GWU) and L. Vetere (PSU) report on behalf of the Swift Team: At 19:12:41 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 100606A (trigger=424031). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 350.603, -66.236 which is RA(J2000) = 23h 22m 25s Dec(J2000) = -66d 14' 07" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a multi-peaked structure with a duration of at least 30 sec. The peak count rate was ~6000 counts/sec (15-350 keV), at ~0 sec after the trigger. The XRT began observing the field at 19:14:18.2 UT, 96.4 seconds after the BAT trigger. XRT found a bright, uncatalogued X-ray source located at RA, Dec 350.6246, -66.2434 which is equivalent to: RA(J2000) = 23h 22m 29.90s Dec(J2000) = -66d 14' 36.2" with an uncertainty of 5.2 arcseconds (radius, 90% containment). This location is 41 arcseconds from the BAT onboard position, within the BAT error circle. No event data are yet available to determine the column density using X-ray spectroscopy. The initial flux in the 2.5 s image was 1.70e-09 erg cm^-2 s^-1 (0.2-10 keV). UVOT took a finding chart exposure of 150 seconds with the White filter starting 106 seconds after the BAT trigger. No credible afterglow candidate has been found in the initial data products. The 2.7'x2.7' sub-image covers 100% of the XRT error circle. The typical 3-sigma upper limit has been about 19.6 mag. The 8'x8' region for the list of sources generated on-board covers 100% of the XRT 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 0.03. Burst Advocate for this burst is S. R. Oates (sro AT mssl.ucl.ac.uk). Please contact the BA by email if you require additional information regarding Swift followup of this burst. In extremely urgent cases, after trying the Burst Advocate, you can contact the Swift PI by phone (see Swift TOO web site for information: http://www.swift.psu.edu/too.html.) //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 10825 SUBJECT: GRB 100606A: Prompt enhanced Swift-XRT position DATE: 10/06/06 20:01:25 GMT FROM: Phil Evans at U of Leicester P.A. Evans (U. Leicester) reports on behalf of the Swift-XRT team: Using 1374.0 ks of promptly downlinked XRT event data for GRB 100606A, we find an enhanced XRT position of the afterglow: RA, Dec: 350.6265, -66.2411 which is equivalent to: RA (J2000) = 23 22 30.37 Dec (J2000) = -66 14 28.1 with an uncertainty of 2.0 arc sec (radius, 90% confidence). Analysis of the promptly available data is online at http://www.swift.ac.uk/sper/424031. Position enhancement is is described by Goad et al. (2007, A&A, 476, 1401) and Evans et al. (2009, MNRAS, 397, 1177). This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 10827 SUBJECT: GRB 100606A: Enhanced Swift-XRT position DATE: 10/06/06 22:40:37 GMT FROM: Phil Evans at U of Leicester P.A. Evans, M.R. Goad, J.P. Osborne and A.P. Beardmore (U. Leicester) report on behalf of the Swift-XRT team. Using 1354 s of XRT Photon Counting mode data and 1 UVOT images for GRB 100606A, we find an astrometrically corrected X-ray position (using the XRT-UVOT alignment and matching UVOT field sources to the USNO-B1 catalogue): RA, Dec = 350.62704, -66.24127 which is equivalent to: RA (J2000): 23h 22m 30.49s Dec (J2000): -66d 14' 28.6" with an uncertainty of 1.8 arcsec (radius, 90% confidence). This position may be improved as more data are received. The latest position can be viewed at http://www.swift.ac.uk/xrt_positions. Position enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans et al. (2009, MNRAS, 397, 1177). This circular was automatically generated, and is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 10828 SUBJECT: GRB 100606A: Swift-BAT refined analysis DATE: 10/06/07 04:23:39 GMT FROM: Scott Barthelmy at NASA/GSFC H. A. Krimm (GSFC/USRA), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC), C. B. Markwardt (GSFC/UMD), S. R. Oates (UCL-MSSL), D. M. Palmer (LANL), T. Sakamoto (GSFC/UMBC), M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC), T. N. Ukwatta (GWU) (i.e. the Swift-BAT team): Using the data set from T-240 to T+962 sec from recent telemetry downlinks, we report further analysis of BAT GRB 100606A (trigger #424031) (Oates, et al., GCN Circ. 10824). The BAT ground-calculated position is RA, Dec = 350.617, -66.234 deg, which is RA(J2000) = 23h 22m 28.1s Dec(J2000) = -66d 14' 03.3" with an uncertainty of 1.1 arcmin, (radius, sys+stat, 90% containment). The partial coding was 25%. The mask-weighted light curve shows an initial FRED peak starting at ~T-0.2 sec, peaking at ~T+0.5 sec. Then there are two peaks at ~T+12 and ~T+20 sec followed by a roughly exponential decay out to ~T+180 sec. Another, weak peak occurs at ~T+200 followed by some very weak emission out to ~T+370 sec, and possibly out to ~T+500 sec. T90 (15-350 keV) is 480 +- 150 sec (estimated error including systematics). The time-averaged spectrum from T+0.3 to T+672.3 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.35 +- 0.10. The fluence in the 15-150 keV band is 6.4 +- 0.4 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T+7.82 sec in the 15-150 keV band is 1.6 +- 0.4 ph/cm2/sec. All the quoted errors are at the 90% confidence level. The results of the batgrbproduct analysis are available at http://gcn.gsfc.nasa.gov/notices_s/424031/BA/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 10829 SUBJECT: GRB 100606A Swift-XRT refined analysis DATE: 10/06/07 09:09:46 GMT FROM: Owen Littlejohns at U of Leicester O. Littlejohns, P. A. Evans, J. P. Osborne (U. Leicester) and S. R. Oates (UCL-MSSL) report on behalf of the Swift-XRT team: We have analysed 4.9 ks of XRT data for GRB 100606A (Oates et al. GCN Circ. 10824), from 86 s to 19.1 ks after the BAT trigger. The data comprise 313 s in Windowed Timing (WT) mode (the first 9 s were taken while Swift was slewing) with the remainder in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Evans et al. (GCN. Circ 10825). The light curve can be modelled with a series of power-law decays. The light curve initially shows some flaring with an underlying decay index of 1.69 (+0.14, -0.10) from T+138 s to T+455 s. The light curve then breaks at T+455 s to a decay with alpha=0.88 (+0.15, -0.26), flares may also be present in this interval, before a final break at T+1641 s after which the decay index is 2.09 (+1.28, -0.16). A spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 1.61 (+/-0.08). The best-fitting absorption column is 2.06 (+0.29, -0.28) x 10^21 cm^-2, in excess of the Galactic value of 2.4 x 10^20 cm^-2 (Kalberla et al. 2005). The PC mode spectrum has a photon index of 1.91 (+0.15, -0.14) and a best-fitting absorption column of 2.2 (+0.5, -0.4) x 10^21 cm^-2. The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 4.4 x 10^-11 (6.2 x 10^-11) erg cm^-2 count^-1. If the light curve continues to decay with a power-law decay index of 2.09, the count rate at T+24 hours will be 2.9 x 10^-4 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.2 x 10^-14 (1.8 x 10^-14) erg cm^-2 s^-1. The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00424031. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 10830 SUBJECT: GRB 100606A: Swift/UVOT Upper Limits DATE: 10/06/07 11:09:41 GMT FROM: Samantha Oates at MSSL S. R. Oates (MSSL-UCL) reports on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 100606A 107s after the BAT trigger (Oates et al., GCN Circ. 10824). We do not detect any source at the enhanced Swift XRT position (Evans et al. GCN Circ. 10827). The 3-sigma upper limits for the finding chart exposures (FC) and summed images are: Filter T_start T_stop Exp(s) Mag (3-sigma upper limit) ------------------------------------------------------------- white (FC) 107 256 147 > 21.08 u (FC) 319 568 246 > 20.35 white 598 6542 461 > 21.70 v 648 6952 333 > 19.86 b 574 6337 312 > 20.76 u 722 7567 487 > 20.47 uvw1 698 7362 490 > 20.54 uvm2 673 7157 274 > 19.93 uvw2 1030 6748 255 > 20.27 ------------------------------------------------------------- The quoted upper limits have not been corrected for the expected Galactic extinction due to the reddening of E_(B-V) = 0.03 mag along the line of sight. All photometry is on the UVOT photometric system described in Poole et al. (2008, MNRAS, 383, 627). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 10831 SUBJECT: GRB 100606A: Gemini-South imaging DATE: 10/06/07 13:21:32 GMT FROM: Nial Tanvir at IofA U.Cambridge A.J. Levan (U. Warwick) and N.R. Tanvir (U. Leicester) report for a larger collaboration: We imaged the location of GRB 100606A (Oates et al. GCN 10824) using GMOS-S on Gemini South. Observations began at 06:02 UT on June 7th, approximately 11 hours after the burst, and were obtained in the r, i and z-bands, with a total of 900s exposure in each band. Within the refined XRT error circle (Evans et al. GCN 10827) we find a faint, and apparently extended source, with r~25 (using archival zero point), which is barely visible in our i and z-band observations, suggesting a relatively blue colour. Although it is plausible that this object contains some contribution from a faint afterglow, the extended source is apparently dominating, and we suggest that this is the host of GRB 100606A. The faint afterglow (r>25), combined with the apparently high X-ray column density (Littlejohns et al. GCN 10829) is consistent with GRB 100606A as a highly extinguished burst. We thank the staff of Gemini South, especially Peter Pessev, for the help in acquiring these data. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 10833 SUBJECT: Konus-Wind observation of GRB 100606A DATE: 10/06/08 10:17:03 GMT FROM: Dmitry Frederiks at Ioffe Institute S. Golenetskii, R. Aptekar, D. Frederiks, E. Mazets, V. Pal'shin, P. Oleynik, M. Ulanov, D. Svinkin, and T. Cline on behalf of the Konus-Wind team, report: The long GRB 100606A (Swift-BAT trigger=424031; Oates et al., GCN 10824; Krimm et al., GCN 10828) triggered Konus-Wind at T0=69163.712s UT (19:12:43.712) The total duration of the burst is ~100 s. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB100606_T69163/ As observed by Konus-Wind the burst had a fluence of 3.9(+/-0.5)x10-5 erg/cm2, and a 256-ms peak flux measured from T0+0.256s of 2.5(+/-0.25)x10-6 erg/cm2/s (both in the 20 keV - 2 MeV energy range). The time-integrated spectrum of the burst (from T0 to T0+82.176 s) is best fit in the 20 keV - 2 MeV range by a power law with exponential cutoff model, for which alpha = -1.05(+/-0.14), and Ep = 945(-266, +551) keV; chi2 = 49/58 dof. The spectrum at the maximum count rate (measured from T0 to T0+8.448 s) is best fit in the 20 keV - 2 MeV range by a power law with exponential cutoff model, for which alpha = -0.68(+/-0.15), and Ep = 767(-126, +175) keV; chi2 = 72/58 dof. All the quoted results are preliminary. All the quoted errors are at the 90% confidence level. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 10835 SUBJECT: GRB 100606A: GROND observations DATE: 10/06/09 12:15:27 GMT FROM: Thomas Kruehler at MPE/MPI A. Nicuesa (TLS Tautenburg), T. Kruehler and J. Greiner (MPE Garching) report on behalf of the GROND team: We observed the field of GRB 100606A (Oates et al., GCN 10824) 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 04:27 UT on June 07, 9.2 hours after the GRB trigger. Within the enhanced XRT error circle (Evans et al. GCN 10827) we confirm the presence of the blue and extended source reported by Levan et al. (GCN 10831) in g' and r' at RA (J2000.0) = 23:22:30.27 Dec (J2000.0) = -66:14:27.1 with typical uncertainties of 0.5" in each coordinate. Similar to Levan et al. (GCN 10831) we also do not find evidence of an optical/NIR afterglow. Stacked images of 270 min total integration time in g'r'i'z' and 80 min in JHK yield the following preliminary upper limits in the AB system, which have been obtained using the GROND zeropoints and 2MASS field stars as reference: g' > 25.7 (24.7 +- 0.2) r' > 25.5 (25.0 +- 0.3) i' > 24.6 z' > 24.1 J > 22.2 H > 21.5 K > 21.0 Magnitudes in brackets denote the brightness of the putative host galaxy. Using the r'-band upper limit and the X-ray brightness at a similar time, beta_oX is constrained to be smaller than 0.6, implying that the burst would not be necessarily 'dark' according to the Jakobsson et al. (2004, ApJ, 617, 21) classification. Thus, our limit neither implies large redshift nor large extinction. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 10836 SUBJECT: GRB 100606A: Suzaku WAM observation of the prompt emission DATE: 10/06/12 16:46:30 GMT FROM: Satoshi Sugita at Aoyama Gakuin U. S. Sugita (Nagoya U.), K. Yamaoka (Aoyama Gakuin U.), A. Daikyuji, N. Ohmori, Y. Nishioka, M. Yamauchi (Univ. of Miyazaki), Y. Hanabata, T. Uehara, T. Takahashi, Y. Fukazawa (Hiroshima U.), Y. Terada, M. Tashiro, S. Hong, W. Iwakiri, K. Takahara, T. Yasuda (Saitama U.), M. Ohno, M. Kokubun, T. Takahashi (ISAS/JAXA), Y. E. Nakagawa, M. Suzuki, T. Tamagawa (RIKEN), N. Vasquez (Tokyo Tech.), Y. Urata, H. M. Lin, P. P. Tsai (NCU), T. Enoto, K. Nakazawa, K. Makishima (Univ. of Tokyo) on behalf of the Suzaku WAM team, report: The long GRB 100606A (Swift/BAT trigger #10824; Oates et al.,) triggered the Suzaku Wide-band All-sky Monitor (WAM) which covers an energy range of 50 keV - 5 MeV at 19:12:41.766 UT (=T0). The observed light curve shows a multi-peaked structure lasting from T0-2s to T0+100s with a duration (T90) of about 65 seconds. The fluence in 100 - 1000 keV was 2.21 (-0.28, +0.17) x10^-5 erg/cm^2. The 1-s peak flux measured from T0+1s was 3.40 (-0.41 +0.28) photons/cm^2/s in the same energy range. Preliminary result shows that the time-averaged spectrum from T0 to T0+65s is well fitted by a power-law with exponential cutoff model: dN/dE = E^{-alpha} * exp(-(2-alpha)*E/Epeak) with alpha 0.63 (-0.30 +0.25), and Epeak 767 (-121 +172) keV (chi^2/d.o.f. = 45.2/52). All the quoted errors are at statistical 90% confidence level, in which the systematic uncertainties are not included. The light curves for this burst are available at: http://www.astro.isas.jaxa.jp/suzaku/HXD-WAM/WAM-GRB/grb/trig/grb_table.html //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 10869 SUBJECT: GRB 100606A: Optical Limits DATE: 10/06/21 00:33:42 GMT FROM: Brian Schmidt at RSAA, ANU (MSSSO) S.Rapoport, J. Scharwaechter, B.P. Schmidt, M.Dopita, M. Bessell RSAA, The Australian National University report We observed the afterglow of the Swift GRB 100606A (S.R. Oates et al. GCN 10824) with the Australian National University's Wide-Field-Spectrograph (WiFeS)+2.3m telescope located at Siding Spring Observatory. WiFeS is a high throughput integral field spectrograph which covers a FoV of 25"x38" (Dopita, M., et al, , Ap&SS,310,255). The spectra were taken in poor conditions (FWHM 3 arcsec ) at the onset of twilight, and cover the wavelength region 3200A-9300A at a resolution of 3000. Data were obtained in two 900 second exposures commencing at UT 19:49:20 Jun 6 (35 minutes after GRB trigger). To maximize image depth, we stacked and remove spectra regions containing skylines to form g,r,i,z images. We did not detect any source within the XRT error circle to limiting magnitudes (5-sigma) of Filter Mag (AB) === === g >18.1 r >19.5 i >19.1 z >18.9 calibrated by comparison to a nearby spectrophometric standard star. The values are not corrected for galactic extinction.