//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 9281 SUBJECT: GRB 090429B: Swift detection of a burst DATE: 09/04/29 05:47:53 GMT FROM: David Palmer at LANL T. N. Ukwatta (GSFC/GWU), S. D. Barthelmy (GSFC), P. A. Evans (U Leicester), N. Gehrels (NASA/GSFC), C. B. Markwardt (CRESST/GSFC/UMD), K. L. Page (U Leicester), D. M. Palmer (LANL), B. A. Rowlinson (U Leicester), M. H. Siegel (PSU), M. Stamatikos (NASA/ORAU) and L. Vetere (PSU) report on behalf of the Swift Team: At 05:30:03 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 090429B (trigger=350854). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 210.704, +32.163 which is RA(J2000) = 14h 02m 49s Dec(J2000) = +32d 09' 48" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed three peaks with a duration of about 5 sec. The peak count rate was ~4000 counts/sec (15-350 keV), at ~0 sec after the trigger. The XRT began observing the field at 05:31:50.0 UT, 106.6 seconds after the BAT trigger. Using promptly downlinked data we find an uncatalogued X-ray source with an enhanced position: RA, Dec 210.6670, 32.1707 which is equivalent to: RA(J2000) = 14h 02m 40.09s Dec(J2000) = +32d 10' 14.6" with an uncertainty of 2.3 arcseconds (radius, 90% containment). This location is 116 arcseconds from the BAT onboard position, within the BAT error circle. This position may be improved as more data are received; the latest position is available at http://www.swift.ac.uk/sper. A power-law fit to a spectrum formed from promptly downlinked event data gives a column density consistent with the Galactic value of 1.2e+20 cm^-2 (Kalberla et al. 2005). UVOT took a finding chart exposure of 150 seconds with the White filter starting 99 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 25% of the BAT error circle but does not overlap 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 BAT error circle and 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 0.01. Burst Advocate for this burst is T. N. Ukwatta (tilan.ukwatta AT gmail.com). 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: 9282 SUBJECT: GRB 090429B: Super-LOTIS early observations DATE: 09/04/29 06:40:06 GMT FROM: Adria C. Updike at Clemson U Adria C. Updike (Clemson University), G. Grant Williams (MMTO Observatory), Peter A. Milne (Steward Observatory), and Dieter H. Hartmann (Clemson University) report: The 0.6m Super-LOTIS telescope at Kitt Peak National Observatory began observing the field of GRB 090429B 40 seconds after the trigger (Ukwatta et al., GCN 9281) under good conditions. Observations consisted sets of 10, 20, and 60 second exposures. No new sources are found in the XRT error circle. The results of the stacked exposures are given below; time is given in seconds after the trigger (midtime of stack). Magnitudes were determined relative to the USNO B1.0 catalog. Band Exposures Time Mag ------------------------------------------- R 5 x 10sec 80 > 17 R 10 x 60sec 580 > 19 Observations are continuing. This message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 9283 SUBJECT: GRB 090429B: GROND Observations DATE: 09/04/29 07:58:36 GMT FROM: Aybuke Kupcu Yoldas at ESO F. Olivares (MPE Garching), A. Kupcu Yoldas (ESO), J. Greiner, T. Kruehler, A. Yoldas (both MPE Garching) report on behalf of the GROND team: We observed the field of GRB 090429B (Swift trigger 350854; Ukwatta et al., GCN #9281) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008, PASP 120, 405) mounted at the 2.2 m ESO/MPI telescope at La Silla Observatory (Chile). Observations started at 05:43 UT, ~13 minutes after the GRB trigger and continued until the source reached the 20 deg horizon limit. They are performed at an average seeing of 1.2 and at an average airmass of 2.5. We do not detect any source within the Swift-XRT error circle reported by Ukwatta et al. (GCN #9281) down to the following limits (based on 4 minutes of exposure time, all in AB system): g' > 23.4 mag r' > 23.3 mag i' > 22.4 mag z' > 21.8 mag J > 21.5 mag H > 20.2 mag K > 19.6 mag Quoted upper limits have been derived using USNO and 2MASS field stars as reference. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 9284 SUBJECT: GRB 090429B: VLT upper limits DATE: 09/04/29 08:30:22 GMT FROM: Paolo D'Avanzo at INAF-OAB Paolo D'Avanzo (Univ. Milano-Bicocca & INAF/Brera), Andrew J. Levan (Univ. Warwick), Daniele Malesani (DARK/NBI), Christina C. Thoene (INAF/Brera), Johan P. U. Fynbo, Jens Hjorth (DARK/NBI), Nial Tanvir (Univ. Leicester), report on behalf of a larger collaboration: We observed the field of GRB 090429B (Ukwatta et al. GCN 9281) with the ESO-VLT in imaging mode with the FORS2 camera. Observations started about 1 hr after the burst. In our stacked images, no afterglow is detected down to the following 3sigma limits: R > 25.3 z > 23.5 Photometry has been calibrated against USNOB1 catalogue and the SDSS. We acknowledge support from the Paranal staff, in particular E. Mason and P. Lynam. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 9286 SUBJECT: GRB090429B: Gemini-N infrared IR candidate DATE: 09/04/29 10:45:17 GMT FROM: Antonino Cucchiara at PSU A. Cucchiara (PSU), A. Levan (U. Warwick), N. Tanvir (U. Leicester), D. B. Fox (PSU) and E. Berger (Harvard U.) report: "On April 29.35 UT we imaged the field of Swift GRB 090429 (Ukwatta et al., GCN 9281) with NIRI on the Gemini-North telescope. We obtained images in J,H and K for a total exposure time of 9, 4.5 and 9 minutes respectively. In the coadded images we identify a possible IR counterpart inside the XRT error circle at the coordinates: RA (J2000): 14:02:40.05 Dec (J2000): +32:10:14.32 with an uncertainty of 0.5". The estimated magnitude are: J = 21.79 +- 0.1 H = 20.08 +- 0.05 K = 19.15 +- 0.03 These values are calibrated using the 2MASS star at RA=14:02:42.20, Dec= +32:10:50.36. Although variability remains to be confirmed, the red J-H colour, coupled with the relatively blue (H-K) is suggestive of a break. Although this may be caused by dust the lack of apparent excess N_H in the X-ray spectrum (GCN 9281) suggests this may not be the case. Hence GRB 090429B should be considered a high-z candidate." We thank the Gemini-N staff for the support in performing this observations, in particular Scott Fisher and Kathy Roth." //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 9288 SUBJECT: GRB 090429B: Enhanced Swift-XRT position DATE: 09/04/29 11:44:00 GMT FROM: Phil Evans at U of Leicester A.P. Beardmore, P.A. Evans, M.R. Goad and J.P. Osborne (U. Leicester) report on behalf of the Swift-XRT team. Using 862 s of XRT Photon Counting mode data and 1 UVOT images for GRB 090429B, 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 = 210.66707, +32.17072 which is equivalent to: RA (J2000): 14h 02m 40.10s Dec (J2000): +32d 10' 14.6" 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, arXiv:0812.3662). This circular was automatically generated, and is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 9290 SUBJECT: GRB 090429B: Swift-BAT refined analysis DATE: 09/04/29 12:09:35 GMT FROM: Scott Barthelmy at NASA/GSFC M. Stamatikos (GSFC/ORAU), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC), E. E. Fenimore (LANL), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC/UMD), D. M. Palmer (LANL), A. M. Parsons (GSFC), T. Sakamoto (GSFC/UMBC), G. Sato (ISAS), J. Tueller (GSFC), T. N. Ukwatta (GWU) (i.e. the Swift-BAT team): Using the data set from T-60 to T+243 sec from the recent telemetry downlink, we report further analysis of BAT GRB 090429B (trigger #350854) (Ukwatta, et al., GCN Circ. 9281). The BAT ground-calculated position is RA, Dec = 210.672, 32.167 deg, which is RA(J2000) = 14h 02m 41.2s Dec(J2000) = +32d 10' 02.0" with an uncertainty of 1.3 arcmin, (radius, sys+stat, 90% containment). The partial coding was 84%. The mask-weighted light curve shows a main peak starting at ~T-4 sec, peaking at ~T-0.1 sec, and ending around T+3 sec. There are two very weak peaks: ~T+30 to ~T+70 sec, and ~T+100 to ~T+110 sec. T90 (15-350 keV) is 5.5 +- 1.0 sec (estimated error including systematics). The time-averaged spectrum from T-4.5 to T+2.4 sec is best fit by a power law with an exponential cutoff. This fit gives a photon index 0.47 +- 0.77, and Epeak of 42.1 +- 5.6 keV (chi squared 29.6 for 56 d.o.f.). For this model the total fluence in the 15-150 keV band is 3.1 +- 0.3 x 10^-7 erg/cm2 and the 1-sec peak flux measured from T-0.28 sec in the 15-150 keV band is 1.6 +- 0.2 ph/cm2/sec. A fit to a simple power law gives a photon index of 1.96 +- 0.13 (chi squared 45.3 for 57 d.o.f.). 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/350854/BA/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 9291 SUBJECT: GRB 090429B: RIMOTS optical upper limits DATE: 09/04/29 14:05:00 GMT FROM: Kenta Kono at Miyazaki U K.Kono, E.Sonoda, N.Ohmori, H.hayasi, K.Noda, A.Daikyuji, Y.Nisioka, M.Yamauchi (University of Miyazaki) We have observed the field covering the error circle of GRB09042 (Swift trigger 350854, GCN 9281, T. N. Ukwatta et al.) with the unfiltered CCD camera on the 30-cm telescope at University of Miyazaki. The observation was started 11:29:13 UT, about 6.0 hr after the Swift 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. (GCN 9281, T. N. Ukwatta et al. GCN 9288, A.P. Beardmore et al. GCN 9290, M. Stamatikos et al.) the upper limits are as follows: -------------------------------------------------------------- Start(UT) End(UT) Num. of frames Limit (mag.) -------------------------------------------------------------- 11:29:13 11:29:33 1 16.4 11:29:13 12:04:10 28 17.9 --------------------------------------------------------------- //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 9298 SUBJECT: GRB 090429B: Swift XRT refined analysis DATE: 09/04/29 20:14:12 GMT FROM: Antonia Rowlinson at U.of Leicester A. Rowlinson (U. Leicester) and T. N. Ukwatta (GSFC/GWU) report on behalf of the Swift-XRT team: We have analysed 8.9 ks of XRT data for GRB 090429B (Ukwatta et al. GCN Circ. 9281), from 104 s to 29.9 ks after the BAT trigger. The data are entirely in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Beardmore et al. (GCN. Circ 9288). The light curve initially shows a slow rise, which can be fitted with a power-law of index 0.89 (+0.36, -0.46). At around T+642 s the light curve breaks to a power-law decay, with index 1.20 (+0.11, -0.10). A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 2.00 (+0.15, -0.24). The best-fitting absorption column is 10.0 (+4.2, -5.3) x 10^20, in excess of the Galactic value of 1.2 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 3.8 x 10^-11 (4.9 x 10^-11) erg cm^-2 count^-1. If the light curve continues to decay with a power-law decay index of 1.20, the count rate at T+24 hours will be 0.0014 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 5.3 x 10^-14 (6.9 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/00350854. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 9306 SUBJECT: GRB 090429B: Gemini-N further nIR observations DATE: 09/04/30 11:38:26 GMT FROM: Nial Tanvir at IofA U.Cambridge A. Levan (U. Warwick), A. Cucchiara (PSU), N. Tanvir (U. Leicester), D. Fox (PSU) & E. Berger (Harvard U.) report: We re-observed the field of GRB 090429B with NIRI on Gemini-N, beginning about 30-Apr 08:00 (UT). The infra-red source reported by Cucchiara et al. (GCN 9286) is detected, but has faded significantly to K=20.0 +/- 0.2 mag. We thus confirm that this source is the afterglow of the burst. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 9309 SUBJECT: GRB 090429B: Swift/UVOT Upper Limits DATE: 09/04/30 16:03:10 GMT FROM: Margaret Chester at PSU M. M. Chester (PSU) and T. N. Ukwatta (GSFC/GWU) report on the behalf of the Swift/UVOT team: The Swift/UVOT observed the field of GRB 090429B starting 78 s after the BAT trigger (Ukwatta et al. 2009, GCN Circ. 9281). Settled exposures started at T+99 s. We do not find any new source at the position of the XRT afterglow (Beardmore et al. 2009, GCN Circ. 9288). Preliminary 3-sigma upper limits for detecting a source in the white finding chart and the co-added images, using a 5 arcsecond radius circular aperture, are: Filter T_start T_stop Exp(s) Mag ---------------------------------------------- white (fc) 99 249 150 >21.0 white 591 10856 1241 >22.2 v 640 12550 1213 >20.6 b 567 6769 381 >20.8 u 311 6621 669 >20.8 uvw1 690 6416 419 >20.5 uvm2 665 6211 439 >21.4 uvw2 616 11762 1339 >20.3 ---------------------------------------------- The quoted upper limits have not been corrected for the expected Galactic extinction corresponding to a reddening of E_{B-V} = 0.015 in the direction of the XRT position (Schlegel, et al. 1998, ApJS, 500, 525). All photometry is on the UVOT photometry system described in Poole et al. (2008, MNRAS, 383, 627). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 12043 SUBJECT: EVLA afterglow limits on the high z GRB090429B DATE: 11/05/28 12:16:12 GMT FROM: Dale A. Frail at NRAO Dale A. Frail (NRAO), Ashley Zauderer (Harvard), Edo Berger (Harvard) and Poonam Chandra (RMC) report on behalf of a larger collaboration: We used the EVLA to image a field toward the Swift burst GRB 090429B (GCNs 9281, 9288, 9290, 9298), for which a photometric redshift of z=9.4 has been recently claimed (Cucchiara et al. astro-ph/1105.4915). The EVLA observed at two frequencies (1 GHz bandwidth each) centered at 4.93 GHz and 6.68 GHz on 2011 April 4.38 UT and 2011 May 6.13 UT. No radio source is detected at the NIR afterglow position. Combining the data from both epochs we derive a 3-sigma limit of 16.6 microJy. This limit corresponds to a spectral luminosity of 2e31 erg/s/Hz. We also reduced archival data taken at a frequency of 8.46 GHz on 2009 April 30.28 UT. The 3-sigma limit for this observation is 132 microJy.