GRB081222A

This page lists all entries on GRB081222A in GRBweb

Summary Fermi GBM IPN Swift GCN 8691 GCN 8692 GCN 8693 GCN 8696 GCN 8697 GCN 8699 GCN 8705 GCN 8707 GCN 8709 GCN 8712 GCN 8713 GCN 8715 GCN 8716 GCN 8717 GCN 8718 GCN 8721 GCN 8724

Summary table
Variable Value Source
GRB_name_Fermi GRB081222204
T0 4:53:59 UTC GCN_circulars,Swift Det
ra 22.7400° Swift
decl -34.0949° Swift
pos_error 6.47e-05° Swift
T90 18.88 s Fermi_GBM
T90_error 2.318 s Fermi_GBM
T90_start 4:54:00.640 UTC Fermi_GBM
fluence 1.19e-05 erg/cm² Fermi_GBM
fluence_error 9.57e-08 erg/cm² Fermi_GBM
redshift 2.7700
T100 24.0 s
GBM_located False
mjd 54822.20415509259 GCN_circulars,Swift Det
Fermi GBM table
GRB_name_Fermi GRB081222204
trigger_name bn081222204
ra 22.7000°
decl -34.1000°
pos_error 2.75e+00°
datum 2008-12-22
t_trigger 4:54:00.256 UTC
T90 18.88 s
T90_error 2.318 s
T90_start 4:54:00.640 UTC
fluence 1.19e-05 erg/cm²
fluence_error 9.57e-08 erg/cm²
flux_1024 1.28e+01 erg/cm²/s
flux_1024_error 2.35e-01 erg/cm²/s
flux_1024_time 3.26e+00 erg/cm²/s
flux_64 1.45e+01 erg/cm²/s
flux_64_error 1.00e+00 erg/cm²/s
IPN table
GRB_name GRB081222A
ra 22.7500°
decl -34.1333°
pos_error 5.00e-02°
redshift 2.7700
Swift table
GRB_name GRB081222A
t_trigger 4:53:59 UTC
ra 22.7400°
decl -34.0949°
pos_error 6.47e-05°
T90 24.0 s
fluence 4.80e-06 erg/cm²
redshift 2.7000
GCN 8691 table
GRB_name GRB081222A
GCN_number 8691
Detection_method Swift Det
t_trigger 4:53:59 UTC
ra 22.7510°
decl -34.1280°
Circular_text TITLE: GCN CIRCULAR NUMBER: 8691 SUBJECT: GRB 081222: Swift detection of a burst with a bright optical afterglow DATE: 08/12/22 05:28:23 GMT FROM: David Palmer at LANL D. Grupe (PSU), M. M. Chester (PSU), J. R. Cummings (NASA/UMBC), N. Gehrels (NASA/GSFC), C. B. Markwardt (CRESST/GSFC/UMD), D. M. Palmer (LANL), J. L. Racusin (PSU), M. Stamatikos (NASA/ORAU) and M. C. Stroh (PSU) report on behalf of the Swift Team: At 04:53:59 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 081222 (trigger=337914). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 22.751, -34.128 which is RA(J2000) = 01h 31m 00s Dec(J2000) = -34d 07' 41" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a multipeaked structure with a duration of about 20 sec. The peak count rate was ~10000 counts/sec (15-350 keV), at 3 sec after the trigger. The XRT began observing the field at 04:54:51.7 UT, 51.8 seconds after the BAT trigger. Using promptly downlinked data we find a bright, fading, uncatalogued X-ray source located at RA, Dec 22.74067, -34.09556 which is equivalent to: RA(J2000) = 01h 30m 57.76s Dec(J2000) = -34d 05' 44.0" with an uncertainty of 3.6 arcseconds (radius, 90% containment). This location is 120 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 2.24e+20 cm^-2 (Kalberla et al. 2005). The initial flux in the 2.5 s image was 3.91e-09 erg cm^-2 s^-1 (0.2-10 keV). UVOT took a finding chart exposure of 150 seconds with the White filter starting 60 seconds after the BAT trigger. There is a candidate afterglow in the rapidly available 2.7'x2.7' sub-image consistent with the XRT candidate. A precise location and magnitude estimate are not available at this time. This burst is consistent with the Fermi GBM burst Trigger 251614441. Burst Advocate for this burst is D. Grupe (grupe AT astro.psu.edu). 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.)
GCN 8692 table
GRB_name GRB081222A
GCN_number 8692
Detection_method Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 8692 SUBJECT: GRB081222: REM candidate afterglow DATE: 08/12/22 05:30:11 GMT FROM: Stefano Covino at Brera Astronomical Observatory S. Covino, P. D'Avanzo, L.A. Antonelli, D. Malesani, D. Fugazza, L. Calzoletti, S. Campana, G. Chincarini, M.L. Conciatore, S. Cutini, V. D'Elia, F. D'Alessio, F. Fiore, P. Goldoni, D. Guetta, C. Guidorzi, G.L. Israel, E. Maiorano, N. Masetti, A. Melandri, E.J.A. Meurs, L. Nicastro, E. Palazzi, E. Pian, S. Piranomonte, L. Stella, G. Stratta, G. Tagliaferri, G. Tosti, V. Testa, S.D. Vergani, F. Vitali report on behalf of the REM team: The robotic 60-cm REM telescope located at La Silla (Chile) observed automatically the field of the GRB 081222 (Grupe et al. GCN8691) starting about 28s after the burst. We detect a bright object in our first H-band image inside the XRT error box at the following coordinates (J2000): R.A. = 01:30:57.59 Dec = -34:05:41.7 with an uncertainty of about 1.0". The object is approximately H~11.1 at about 1min after the burst and faded rapidly during the next observations. Further observations are in progress
GCN 8693 table
GRB_name GRB081222A
GCN_number 8693
Detection_method correction
ra 22.7398°
decl -34.0949°
Circular_text TITLE: GCN CIRCULAR NUMBER: 8693 SUBJECT: GRB 081222: GROND Detection of the Optical/NIR Afterglow DATE: 08/12/22 08:42:04 GMT FROM: Adria C. Updike at Clemson U A. Updike (Clemson University), P. Afonso, C. Clemens, and J. Greiner (all MPE Garching) report on behalf of the GROND team: We observed the field of GRB 081222 (Swift trigger 337914, Grupe et al., GCN #8691) 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 05:26 UT on Dec 22, 2008, 32 min after the GRB trigger. They were performed at an average seeing of 1.0" and at high airmass. We detect the source within the Swift-XRT error circle reported by Grupe et al. (GCN #8691) and Covino et al. (GCN #8692) at RA (J2000) = 01h 30m 57.56s DEC (J2000) = -34d 05' 41.5'' with an uncertainty of 0.5". We obtained 8 min of total exposures in g'r'i'z'JHK. Preliminary magnitudes (calibrated against field stars in the USNO B1.0 and 2MASS catalogs), exposure length (in seconds, NIR bands co-added), and midtimes are as follows. BAND MAGNITUDE EXP MIDTIME (UT) -------------------------------------------- g' 19.08 +/- 0.01 115 05:27:13 i' 18.04 +/- 0.01 115 05:27:13 z' 18.24 +/- 0.01 115 05:27:13 J 16.12 +/- 0.03 480 05:29:18 H 15.45 +/- 0.02 480 05:29:18 K 14.92 +/- 0.03 480 05:29:18 Tracking problems made data reduction difficult, especially in the r' band, in which we detect the object but could not properly calibrate the field. The object is seen in g' band, implying a redshift smaller than 3.5. No correction has been made for galactic extinction.
GCN 8696 table
GRB_name GRB081222A
GCN_number 8696
Detection_method Swift-UVOT Det
Circular_text TITLE: GCN CIRCULAR NUMBER: 8696 SUBJECT: GRB081222: Swift/UVOT detection of an optical afterglow DATE: 08/12/22 12:52:27 GMT FROM: Alice Breeveld at MSSL-UCL A.A. Breeveld (MSSL/UCL) and D. Grupe (PSU) report on behalf of the Swift UVOT team: The Swift/UVOT started settled observations of the burst GRB081222 (Grupe et al. GCN Circ. 8691) with the finding chart exposure in white, 60s after the BAT trigger. The afterglow is detected in the white and u filters at: 01h 30m 57.59s -34d 05' 41.49" with a 0.5" 90% confidence limit. This position is consistent with the XRT (Grupe et al. GCN Circ. 8691), REM (Covino et al. GCN Circ. 8692) and GROND (Updike et al. GCN Circ. 8693) positions. The two white exposures show that the afterglow is fading with an estimated temporal slope of alpha = 0.85. The initial UVOT magnitudes are as follows: Filter Tstart(s) Tstop(s) Exp(s) Magnitude white 60 210 147.4 14.84+/-0.02 white 873 1023 147.4 17.36+/-0.03 u 272 522 245.8 16.32+/-0.03 The values quoted above are in the UVOT photometric system (Poole et al. 2008, MNRAS, 383, 627) and are not corrected for the expected Galactic extinction corresponding to a reddening of E(B-V)=0.021 mag in the direction of the burst (Schlegel et al. 1998).
GCN 8697 table
GRB_name GRB081222A
GCN_number 8697
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 8697 SUBJECT: GRB081222, optical observation DATE: 08/12/22 13:43:55 GMT FROM: Norisuke Ohmori at Miyazaki U E.Sonoda, H.Tanaka, R.Hara, N.Ohmori, K.Kono, H.hayasi, A.Daikyuji, K.Noda, Y.Nisioka, M.Yamauchi (University of Miyazaki) We have observed the field covering the error circle of GRB081222 (Swift trigger 337914, Grupe et al., GCN 8691) with the unfiltered CCD camera on the 30-cm telescope at University of Miyazaki. The observation was started 08:41:19 UT, about 3.78 hr after the Swift trigger time. We have compared our data of 30 sec exposures with the USNO-A2.0 catalog, the upper limits are as follows: -------------------------------------------------------------- Start(UT) End(UT) Num. of frames Limit (mag.) -------------------------------------------------------------- 10:36:04 10:36:19 1 ~16 10:36:04 10:49:52 12 ~17 ---------------------------------------------------------------
GCN 8699 table
GRB_name GRB081222A
GCN_number 8699
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 8699 SUBJECT: GRB 081222: Faulkes Telescope South observations DATE: 08/12/22 13:51:17 GMT FROM: Cristiano Guidorzi at Ferrara U,Italy A. Melandri (Liverpool JMU), C. Guidorzi (U. Ferrara), D. Carter (Liverpool JMU) report on behalf of a larger collaboration: On 2008 December 22 (10:17:46 UT) we began observing the field of GRB 081222 (Grupe et al. GCN Circ. 8691) with the Faulkes Telescope South. Observations consisted of two sequences of 6x300s exposures acquired using the SDSS-i and SDSS-r filters, respectively. We clearly detect the optical afterglow reported by REM (Covino et al. GCN Circ. 8692) and GROND (Updike et al. GCN Circ. 8693), with the following magnitudes: Telescope Filter T_mid[hr] Exposure[s] Mag -------------------------------------------------------------- FTS SDSS-i 5.47 2x300 20.45 +/- 0.25 FTS SDSS-r 6.01 2x300 21.34 +/- 0.30 -------------------------------------------------------------- The calibration was performed using the R2 and I magnitudes of several USNOB-1 catalogue field objects. Uncertainties include the different zero points of the USNOB-1 stars. Compared with the value reported by GROND (Updike et al. GCN Circ. 8693), we estimate a power-law index between the two epochs of about 1.1 .
GCN 8705 table
GRB_name GRB081222A
GCN_number 8705
Detection_method Swift Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 8705 SUBJECT: GRB 081222: Swift XRT refined analysis DATE: 08/12/22 16:14:12 GMT FROM: Dirk Grupe at PSU/Swift-XRT Dirk Grupe (PSU) reports on behalf of the Swift-XRT team: The XRT began observing the field of GRB 081222 (trigger=337914; Grupe et al., GCN Circ 8691) on 2008-December-22 at 04:54:51.7 UT, 51.8 seconds after the BAT trigger. The 0.3-10 keV X-ray light curve of the first five orbits displays a smooth light curve that can be fitted with an initial decay slope alpha1 = 0.90+/-0.02 with a break at 1420+/-100s followed by a steeper decay slope alpha2=1.20+/-0.02. The spectrum of the Windowed Timing data of the first orbit can be well fitted by an absorbed single power law model with a photon index Gamma = 2.01 +/- 0.20 and a column density NH=(4.61+/-0.80)e20 which is in excess of the Galactic column density in the direction of the burst of NH-gal=2.24e20 (Kalberla et al. 2005). The photon counting mode data of the first five orbits are consistent with this result. If the underlying power law decay of 1.2 continues as is, we predict an XRT count rate of 0.030 counts/s at T+24 hours or 1e-12 ergs/s/cm2 and at T+48 hours 0.015 counts/s or 5e-13 ergs/s/cm2. This circular is an official product of the Swift-XRT team. [GCN OPS NOTE(23dec08): Per author's request, the "081221" in the first line was changed to "081222".]
GCN 8707 table
GRB_name GRB081222A
GCN_number 8707
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 8707 SUBJECT: GRB081222 optical limit by "Pi of the Sky" DATE: 08/12/22 16:23:11 GMT FROM: Marcin Sokolowski at Soltan Inst. Nuc Studies,Warsaw M.Cwiok, W.Dominik, G.Kasprowicz, A.Majcher, A.Majczyna, K.Malek, L.Mankiewicz, K.Nawrocki, L.W.Piotrowski, D.Rybka, M.Sokolowski, J.Uzycki, G.Wrochna, M.Zaremba, A.F.Zarnecki on behalf of "Pi of the Sky" collaboration http://grb.fuw.edu.pl During the night 20081222 the "Pi of the Sky" apparatus observed the position of GRB081222 in the sky scan mode. Three 10s images of this field have been taken at 02:10:44 - 02:11:21 ( 2 hours 43 min 16 sec before the GRB). No new object is seen within the error box and the limit is 12.5 magnitudo. After receiving the trigger from Swift, the field was observed 63s after the GRB. No new object has been found within the Swift-BAT error box. The limiting magnitude (unfiltered) on single 10s exposures is: 04:55:03 - 04:55:13 - 12.0 mag 04:55:16 - 04:55:26 - 12.0 mag 04:55:28 - 04:55:38 - 12.0 mag The field was observed until 06:00:17, no new object brighter then 12.0mag was observed. The limit on 20 coadded images is 12.5 mag.
GCN 8709 table
GRB_name GRB081222A
GCN_number 8709
Detection_method Swift-BAT Det
ra 22.7480°
decl -34.0950°
Circular_text TITLE: GCN CIRCULAR NUMBER: 8709 SUBJECT: GRB 081222, Swift-BAT refined analysis DATE: 08/12/22 19:28:59 GMT FROM: Jay R. Cummings at NASA/GSFC/Swift E. E. Fenimore (LANL), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC), D. Grupe (PSU), H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC/UMD), K. McLean (GSFC/UMD), D. M. Palmer (LANL), A. M. Parsons (GSFC), T. Sakamoto (GSFC/UMBC), G. Sato (ISAS), M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC), T. N. Ukwatta (GWU) (i.e. the Swift-BAT team): Using the data set from T-119 to T+183 sec from the recent telemetry downlink, we report further analysis of BAT GRB 081222 (trigger #337914) (Grupe, et al., GCN Circ. 8691). The BAT ground-calculated position is RA, Dec = 22.748, -34.095 deg which is RA(J2000) = 01h 30m 59.5s Dec(J2000) = -34d 05' 41.4" with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment). The burst was in the fully-coded field of view. The mask-weighted light curve shows a main peak with several subpeaks from about T+0 to T+20 sec and an exponential tail visible to about T+70 sec. T90 (15-350 keV) is 24 +- 3 sec (estimated error including systematics). The time-averaged spectrum from T-0.6 to T+38.0 sec is best fit by a power law with an exponential cutoff. This fit gives a photon index 1.08 +- 0.15, and Epeak of 131 +- 31 keV (chi squared 45.61 for 56 d.o.f.). For this model the total fluence in the 15-150 keV band is 4.8 +- 0.1 x 10^-06 erg/cm2 and the 1-sec peak flux measured from T+3.45 sec in the 15-150 keV band is 7.7 +- 0.2 ph/cm2/sec. A fit to a simple power law gives a photon index of 1.48 +- 0.03 (chi squared 68.25 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/337914/BA/
GCN 8712 table
GRB_name GRB081222A
GCN_number 8712
Detection_method Swift-UVOT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 8712 SUBJECT: GRB081222: Swift/UVOT further observations DATE: 08/12/23 12:15:56 GMT FROM: Alice Breeveld at MSSL-UCL Alice Breeveld (MSSL), Wayne Landsman (GSFC), Paul Kuin (MSSL) and Dirk Grupe (PSU) report on behalf of the Swift/UVOT team: Further analysis of Swift/UVOT data of GRB081222 (Grupe et al., GCN Circ. 8691), shows that the burst was detected in the v and b filters in addition to the white and u filters described in the initial circular (Breeveld et al., GCN Circ. 8696). The source is not detected in any of the UV filters, in single or co-added exposures. The initial magnitudes and upper limits are given in the table below: Filter Tstart(s) Tstop(s) Exp(s) Magnitude white 60 210 147 14.84+/-0.02 white 873 1023 147 17.36+/-0.03 v 602 622 20 16.20+/-0.02 b 528 548 20 16.86+/-0.02 u 272 522 246 16.32+/-0.03 uvw1 652 1815 142 >20.9 (3-sigma UL) uvm2 627 1790 127 >21.0 (3-sigma UL) uvw2 577 1914 124 >21.1 (3-sigma UL) A 49s UV grism spectrum was obtained beginning 216s after the trigger. The very low S/N quicklook spectrum shows a continuum of about 3e-15 erg/s/cm2/A longward of ~3400 A. No flux is detected shortward of 3400 A, even though the grism sensitivity increases toward shorter wavelengths. If this is the wavelength of the Lyman edge, then the redshift of GRB081222 is ~2.7. The detection of GRB081222 in the u filter and the non-detection in UVW1 filter are consistent with this redshift. The values quoted above are in the UVOT photometric system (Poole et al. 2008, MNRAS, 383, 627) and are not corrected for the expected Galactic extinction corresponding to a reddening of E(B-V)=0.021 mag in the direction of the burst (Schlegel et al. 1998).
GCN 8713 table
GRB_name GRB081222A
GCN_number 8713
Detection_method Optical
redshift 2.7700
Circular_text TITLE: GCN CIRCULAR NUMBER: 8713 SUBJECT: GRB 081222: Gemini-South absorption redshift DATE: 08/12/23 14:58:35 GMT FROM: Antonino Cucchiara at PSU A. Cucchiara, D. B. Fox (Penn State), S. B. Cenko (Berkeley) and E. Berger (Harvard) report on behalf of a larger collaboration: Starting at 01:02 UT on 2008 December 23 we observed the optical counterpart of GRB 081222 (Grupe et al., GCN 8691, Covino et al., GCN 8692 and Updike et al. 8693) using Gemini-South with the GMOS-South spectrograph (R~1600). We acquired 2x900s spectra covering the wavelength range 4000A-8000A. We detect a damped Lyman-alpha system (DLA) at redshift z=2.77. We also detect several metal absorption features which we interpret as SiIV(1393,1402), SiII1526 and 1260, SiII*1264, CII1334, CII*1335, CIV(1548,1550), FeII1608 and NiII(1454) at the same redshift. In combination with the strong metal absorption features, the detection of a DLA at z = 2.77 confirms that this is the redshift of GRB 081222 and its host galaxy. We thank the Gemini staff, in particular Henry Lee, for conducting these observations.
GCN 8715 table
GRB_name GRB081222A
GCN_number 8715
Detection_method Fermi GBM Det
t_trigger 4:54:00.250 UTC
Circular_text TITLE: GCN CIRCULAR NUMBER: 8715 SUBJECT: GRB 081222: Fermi GBM observation DATE: 08/12/23 16:28:19 GMT FROM: Elisabetta Bissaldi at MPE E.Bissaldi (MPE) and S. McBreen (UCD/MPE) report on behalf of the Fermi GBM Team: "At 04:54:00.25 UT on 22 December 2008, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 081222 (trigger 251614441 / 081222204), which was also detected by the Swift-BAT (Grupe et al., GCN Circular 8691 and Fenimore et al., GCN Circular 8709). The angle from the Fermi LAT boresight is 50 degrees. This burst was also independently detected by INTEGRAL SPI-ACS. The GBM light curve consists of a main pulse with a duration (T90) of about 30 s (8-1000 keV) and T50 of about 10 s (8-1000 keV). The time-averaged spectrum from T0 to T0+11.52 s is best fit by a Band function with Epeak = 134 +/- 9, alpha = -0.55 +/- 0.07 and beta = -2.10 +/- 0.06. The event fluence (8-1000 keV) in this time interval is (1.35 +/- 0.08)E-05 erg/cm^2. The 1-sec peak photon flux measured starting from T0+3.3 s in the 8-1000 keV band is 14.8 +/- 1.4 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."
GCN 8716 table
GRB_name GRB081222A
GCN_number 8716
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 8716 SUBJECT: VLA radio upper limit on GRB 081222 DATE: 08/12/23 16:34:08 GMT FROM: Poonam Chandra at U Virginia/NRAO Poonam Chandra (RMC) and Dale A. Frail (NRAO) report on behalf of the Caltech-NRAO-Carnegie GRB Collaboration: "We used the Very Large Array to observe the field of view toward optically bright GRB 081222 (GCN 8691) at a frequency of 8.46 GHz on 2008 Dec 23.17 UT. The GRB radio afterglow is undetected and the peak radio flux at the REM optical afterglow position (GCN 8692) is 54 53 uJy. The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc."
GCN 8717 table
GRB_name GRB081222A
GCN_number 8717
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 8717 SUBJECT: GRB 081222:Optical afterglow observation DATE: 08/12/23 18:13:10 GMT FROM: Rupak Roy at ARIES Rupak Roy, Brajesh Kumar, S. B. Pandey and Brijesh Kumar (ARIES, NainiTal, India, on behalf of larger Indian GRB collaboration) GRB 081222, localized by Swift (Grupe et al. GCN 8691), was observed with 1.04m telescope at NainiTal starting ~ 9 hours after the burst in R_c and I_c filters. Photometry of the co-added R_c frames (300 sec x 6) did not detect the optical afterglow candidate (Covino et al. GCN 8692) down to a limiting magnitude of ~ 21 mag in comparison to nearby USNO stars. This message may be cited.
GCN 8718 table
GRB_name GRB081222A
GCN_number 8718
Detection_method Other
redshift 2.7700
Circular_text TITLE: GCN CIRCULAR NUMBER: 8718 SUBJECT: GRB 081222: Gemini-N confirmation of redshift z=2.77 DATE: 08/12/23 20:14:39 GMT FROM: John Graham at STScI J. F. Graham (STScI/JHU), N. R. Tanvir (U. Leicester), A. S. Fruchter (STScI), K. Wiersema (U. Leicester), A. J. Levan (U. Warwick) report on behalf of a larger collaboration: We observed the afterglow of GRB 081222 with Gemini-North/GMOS Nod & Shuffle spectroscopy beginning 22 Dec 2008 06:38 UT, approximately 105 minutes post-burst. From absorption lines of SiII, CIV, and FeII, we confirm the redshift reported in GCN 8713 (Cucchiara et al.) of z=2.77. We also find tentative evidence for a lower redshift system at z=2.74. We thank the Gemini staff, in particular Ricardo Schiavon, for conducting these observations.
GCN 8721 table
GRB_name GRB081222A
GCN_number 8721
Detection_method Konus-Wind Det
t_trigger 4:54:02.534 UTC
Circular_text TITLE: GCN CIRCULAR NUMBER: 8721 SUBJECT: Konus-Wind observation of GRB 081222 DATE: 08/12/24 14:14:00 GMT FROM: Valentin Pal'shin at Ioffe Inst S. Golenetskii, R.Aptekar, E. Mazets, V. Pal'shin, D. Frederiks, P. Oleynik, M. Ulanov, D. Svinkin, and T. Cline on behalf of the Konus-Wind team, report: The long GRB 081222 (Swift-BAT trigger #337914: Grupe et al., GCN 8691; Fenimore et al., GCN 8709) triggered Konus-Wind at T0=17642.534 s UT (04:54:02.534). The burst light curve shows a single pulse with a duration of ~12 s. There is a hint of the weak tail detected by the Swift-BAT (Fenimore et al., GCN 8709) in the K-W G1 band (~20-80 keV). As observed by Konus-Wind the burst had a fluence of 1.32(-0.40, +0.48)x10^-5 erg/cm2, and a 256-ms peak flux measured from T0+4.688 s of 2.22(-0.73, +0.87)x10^-6 erg/cm2/s (both in the 20 keV - 1 MeV energy range). The time-integrated spectrum of the burst (from T0 to T0+16.640 s) can be fitted (in the 20 keV - 1 MeV range) by GRB (Band) model for which: the low-energy photon index is alpha = -0.67(-0.33, +0.39), the high energy photon index beta = -2.35(-1.25, +0.30), the peak energy Ep = 165(-29, +47) keV (chi2 = 63.0/51 dof). All the quoted errors are at the 90% confidence level. Assuming z = 2.77 (Cucchiara et al., GCN 8713; Graham et al., GCN 8718) and a standard cosmology model with H_0 = 70 km/s/Mpc, Omega_M = 0.27, Omega_\Lambda = 0.73, the isotropic energy release E_iso ~2.4x10^53 erg, the peak luminosity (L_iso)_max ~ 1.5x10^53 erg/s, and Ep_rest ~600 keV. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB081222_T17642/
GCN 8724 table
GRB_name GRB081222A
GCN_number 8724
Detection_method MITSuME
Circular_text TITLE: GCN CIRCULAR NUMBER: 8724 SUBJECT: GRB 081222: MITSuME optical observation DATE: 08/12/25 01:51:58 GMT FROM: Michitoshi Yoshida at Okayama Astrophysical Obs D. Kuroda, M. Yoshida, K. Yanagisawa, Y. Shimizu, S. Nagayama, H. Toda (OAO, NAOJ) and N. Kawai (Tokyo Tech) report on behalf of the MITSuME collaboration: We observed the field of GRB 081222 (Grupe et al. GCN 8691) with the optical three color (g', Rc and Ic) imager attached to the MITSuME 50cm telescope of Okayama Astrophysical Observatory on Dec.22 2008 UT. We detected a fading point source at the position of the X-ray - optical afterglow candidate (Covino et al. GCN 8692; Updike et al. GCN8693; Grupe GCN 8705) in Rc band. Photometric results are listed below. We used GSC2.3 catalog for flux calibration. # Mid-MJD Mid-UT EXP-T g' Rc Ic ------------------------------------------------------------- 54822.401100 09:37:36 540.0 >18.3 18.0+/-0.3 >17.8 54822.438455 10:31:23 2940.0 >19.2 18.9+/-0.3 >18.2 54822.469650 11:16:18 4500.0 >19.2 19.3+/-0.4 18.6+/-0.3 -------------------------------------------------------------