GRB221226B

This page lists all entries on GRB221226B in GRBweb

Summary Fermi GBM IPN Swift GCN 33107 GCN 33108 GCN 33109 GCN 33110 GCN 33111 GCN 33112 GCN 33114 GCN 33115 GCN 33119

Summary table
Variable Value Source
GRB_name_Fermi GRB221226945
T0 22:41:20 UTC GCN_circulars,Fermi GBM Det
ra 22.9086° Swift
decl -41.5267° Swift
pos_error 2.59e-04° Swift
T90 4.864 s Fermi_GBM
T90_error 2.828 s Fermi_GBM
T90_start 22:41:20.163 UTC Fermi_GBM
fluence 1.14e-06 erg/cm² Fermi_GBM
fluence_error 1.58e-08 erg/cm² Fermi_GBM
redshift 2.6940
T100 5.027 s
GBM_located False
mjd 59939.94537037037 GCN_circulars,Fermi GBM Det
Fermi GBM table
GRB_name_Fermi GRB221226945
trigger_name bn221226945
ra 22.9088°
decl -41.5264°
pos_error 5.16e+00°
datum 2022-12-26
t_trigger 22:41:20.419 UTC
T90 4.864 s
T90_error 2.828 s
T90_start 22:41:20.163 UTC
fluence 1.14e-06 erg/cm²
fluence_error 1.58e-08 erg/cm²
flux_1024 4.06e+00 erg/cm²/s
flux_1024_error 2.15e-01 erg/cm²/s
flux_1024_time 2.56e-01 erg/cm²/s
flux_64 6.36e+00 erg/cm²/s
flux_64_error 9.42e-01 erg/cm²/s
IPN table
GRB_name GRB221226B
ra 22.9167°
decl -41.5500°
pos_error 5.00e-02°
redshift 2.6940
Swift table
GRB_name GRB221226B
t_trigger 22:41:20 UTC
ra 22.9086°
decl -41.5267°
pos_error 2.59e-04°
T90 3.44 s
fluence 5.40e-07 erg/cm²
redshift 2.6940
GCN 33107 table
GRB_name GRB221226B
GCN_number 33107
Detection_method Fermi GBM final loc
t_trigger 22:41:20 UTC
ra 16.3000°
decl -53.0000°
Circular_text TITLE: GCN CIRCULAR NUMBER: 33107 SUBJECT: GRB 221226B: Fermi GBM Final Real-time Localization DATE: 22/12/26 22:51:47 GMT FROM: Fermi GBM Team at MSFC/Fermi-GBM The Fermi GBM team reports the detection of a likely LONG GRB At 22:41:20 UT on 26 Dec 2022, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 221226B (trigger 693787285.418586 / 221226945). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 16.3, Dec = -53.0 (J2000 degrees, equivalent to J2000 01h 05m, -53d 00'), with a statistical uncertainty of 9.8 degrees. The angle from the Fermi LAT boresight is 46.0 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn221226945/quicklook/glg_skymap_all_bn221226945.png The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn221226945/quicklook/glg_healpix_all_bn221226945.fit The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn221226945/quicklook/glg_lc_medres34_bn221226945.gif
GCN 33108 table
GRB_name GRB221226B
GCN_number 33108
Detection_method Swift Det
t_trigger 22:41:20 UTC
ra 22.9170°
decl -41.5540°
Circular_text TITLE: GCN CIRCULAR NUMBER: 33108 SUBJECT: GRB 221226B: Swift detection of a burst DATE: 22/12/26 23:00:32 GMT FROM: David Palmer at LANL S. B. Cenko (GSFC), J.D. Gropp (PSU), J. A. Kennea (PSU), H. A. Krimm (NSF), S. Laha (GSFC/UMBC), A. Y. Lien (U Tampa), F. E. Marshall (NASA/GSFC), K. L. Page (U Leicester), D. M. Palmer (LANL) and T. M. Parsotan (GSFC/UMBC/CRESSTII) report on behalf of the Neil Gehrels Swift Observatory Team: At 22:41:20 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 221226B (trigger=1145959). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 22.917, -41.554 which is RA(J2000) = 01h 31m 40s Dec(J2000) = -41d 33' 13" 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 about 10 sec. The peak count rate was ~2200 counts/sec (15-350 keV), at ~1 sec after the trigger. The XRT began observing the field at 22:42:32.4 UT, 72.4 seconds after the BAT trigger. Using promptly downlinked data we find a fading, uncatalogued X-ray source located at RA, Dec 22.90890, -41.52648 which is equivalent to: RA(J2000) = 01h 31m 38.14s Dec(J2000) = -41d 31' 35.3" with an uncertainty of 3.5 arcseconds (radius, 90% containment). This location is 101 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 https://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 1.69 x 10^20 cm^-2 (Willingale et al. 2013). UVOT took a finding chart exposure of 150 seconds with the White filter starting 75 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 none of the XRT error circle. 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 0.017. Burst Advocate for this burst is S. B. Cenko (brad.cenko AT nasa.gov). 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/)
GCN 33109 table
GRB_name GRB221226B
GCN_number 33109
Detection_method Swift-XRT Det
ra 22.9097°
decl -41.5267°
Circular_text TITLE: GCN CIRCULAR NUMBER: 33109 SUBJECT: GRB 221226B: Enhanced Swift-XRT position DATE: 22/12/27 03:22:35 GMT FROM: Phil Evans at U of Leicester M.R. Goad, J.P. Osborne, A.P. Beardmore and P.A. Evans (U. Leicester) report on behalf of the Swift-XRT team. Using 1173 s of XRT Photon Counting mode data and 2 UVOT images for GRB 221226B, 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 = 22.90972, -41.52669 which is equivalent to: RA (J2000): 01h 31m 38.33s Dec (J2000): -41d 31' 36.1" with an uncertainty of 2.6 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.
GCN 33110 table
GRB_name GRB221226B
GCN_number 33110
Detection_method Swift-BAT Det
ra 22.9085°
redshift 2.6940
Circular_text TITLE: GCN CIRCULAR NUMBER: 33110 SUBJECT: GRB 221226B: VLT/X-shooter redshift and host galaxy DATE: 22/12/27 09:26:14 GMT FROM: Dong Xu at NAOC/CAS D. Xu (NAOC), A. Chrimes (Radboud Univ.), B. Schneider (MIT), L. Izzo (DARK/NBI), A. Saccardi (GEPI, Observatoire de Paris), Z.P. Zhu (NAOC, HUST), N.R. Tanvir (Univ. Leicester) report on behalf of the Stargate collaboration: We observed the field of GRB 221226B detected by Swift (Cenko et al., GCN 33108) and Fermi (Fermi GBM team, GCN 33107) using the ESO VLT UT3 (Melipal) equipped with the X-shooter spectrograph. Our spectra cover the wavelength range 3000-21000 AA, and consist of 4 exposures by 1200 s each. The observations started at 01:10:06 UT on 2022-12-27, i.e., ~2.48 hr after BAT trigger. The optical afterglow of the burst is detected at coordinates R.A.(J2000) = 01:31:38.036 Dec.(J2000) = - 41:31:37.25 with an uncertainty of ~0.3 arcsec and r = 22.0 +/- 0.1 mag, calibrated with Legacy Survey nearby stars. A broad absorption feature is visible around 4490 AA, which we identify as being due to H I. From detection of multiple absorption features, which we interpret as being due to S II, Si II, O I, C II, Si IV, Al III, NV, and emission features due to [O II] and Hbeta, we infer a common redshift of z = 2.694. We conclude this is the redshift of the burst. Note that at the optical afterglow position, the Legacy Survey presents an extended source with r = 23.82 mag, which is likely the host galaxy of the burst, being consistent with the the detection of emission features in the X-shooter spectra. We acknowledge excellent support from the ESO observing staff in Paranal, in particular Pascale Hibon and Ditte Slumstrup.
GCN 33111 table
GRB_name GRB221226B
GCN_number 33111
Detection_method Swift-XRT Other
redshift 2.6940
Circular_text TITLE: GCN CIRCULAR NUMBER: 33111 SUBJECT: GRB 221226B: Swift-XRT refined Analysis DATE: 22/12/27 11:41:45 GMT FROM: Phil Evans at U of Leicester M. Capalbi (INAF-IASFPA), M. Perri (SSDC & INAF-OAR), J.A. Kennea (PSU), A. Tohuvavohu (U. Toronto), D.N. Burrows (PSU), P.A. Evans (U. Leicester), J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), V. D'Elia (SSDC & INAF-OAR) and S.B. Cenko report on behalf of the Swift-XRT team: We have analysed 6.2 ks of XRT data for GRB 221226B (Cenko et al. GCN Circ. 33108), from 56 s to 40.4 ks after the BAT trigger. The data comprise 14 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 Goad et al. (GCN Circ. 33109). The light curve can be modelled with a power-law decay with a decay index of alpha=1.58 (+0.13, -0.12). A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 1.5 (+0.4, -0.3). The best-fitting absorption column is 7 (+23, -7) x 10^21 cm^-2, at a redshift of 2.694, in addition to the Galactic value of 1.7 x 10^20 cm^-2 (Willingale et al. 2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 4.3 x 10^-11 (4.6 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Galactic foreground: 1.7 x 10^20 cm^-2 Intrinsic column: 7 (+23, -7) x 10^21 cm^-2 at z=2.694 Photon index: 1.5 (+0.4, -0.3) If the light curve continues to decay with a power-law decay index of 1.58, the count rate at T+24 hours will be 6.9 x 10^-5 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 3.0 x 10^-15 (3.2 x 10^-15) erg cm^-2 s^-1. The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/01145959. This circular is an official product of the Swift-XRT team.
GCN 33112 table
GRB_name GRB221226B
GCN_number 33112
Detection_method Fermi GBM Det
t_trigger 22:41:20 UTC
Circular_text TITLE: GCN CIRCULAR NUMBER: 33112 SUBJECT: GRB 221226B: Fermi GBM Observation DATE: 22/12/27 13:16:51 GMT FROM: Rachel Hamburg at UAH S. Lesage (UAH) and C. Meegan (UAH) report on behalf of the Fermi Gamma-ray Burst Monitor Team: "At 22:41:20 UT on 26 December 2022, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 221226B (trigger 693787285/221226945), which was also detected by Swift BAT (S. B. Cenko et al. 2022, GCN 33108) and has a measured redshift from the VLT/X-Shooter (GCN 33110). The Fermi GBM Final Real-time Localization (GCN 33107) is consistent with the Swift BAT position. The angle from the Fermi LAT boresight is 58 degrees. The GBM light curve consists of a single emission episode with a duration (T90) of about 5 s (50-300 keV). The time-averaged spectrum from T0+0.002 to T0+2.592 s is best fit by a power law function with an exponential high-energy cutoff. The power law index is 0.2 +/- 0.2 and the cutoff energy, parameterized as Epeak, is 104 +/- 8 keV. The event fluence (10-1000 keV) in this time interval is (7.8 +/- 0.5)E-07 erg/cm^2. The 1-sec peak photon flux measured starting from T0+0.3 s in the 10-1000 keV band is 4.1 +/- 0.2 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog: https://heasarc.gsfc.nasa.gov/W3Browse/fermi/fermigbrst.html For Fermi GBM data and info, please visit the official Fermi GBM Support Page: https://fermi.gsfc.nasa.gov/ssc/data/access/gbm/"
GCN 33114 table
GRB_name GRB221226B
GCN_number 33114
Detection_method Swift-UVOT Det
Circular_text TITLE: GCN CIRCULAR NUMBER: 33114 SUBJECT: GRB 221226B: Swift-UVOT Detection DATE: 22/12/27 17:23:08 GMT FROM: Noel Klingler at NASA-GSFC / UMBC N. Klingler (UMBC/NASA-GSFC/CRESST II) reports on behalf of the Swift/UVOT team: The Swift-UVOT began settled observations of the field of GRB 221226B 76 s after the BAT trigger (Cenko et al., GCN Circ. 33108). A source consistent with the XRT position (Goad et al., GCN Circ. 33109) and consistent with the optical counterpart reported by VLT/X-shooter (Xu et al., GCN Circ. 33110) is detected in the initial UVOT exposures. Preliminary detections and 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the early exposures are: Filter T_start(s) T_stop(s) Exp(s) Mag white 76 226 147 20.54 +/- 0.22 v 4408 4608 197 >19.3 b 3793 3993 197 >20.0 u 288 5132 278 >20.1 w1 4818 5018 197 >20.0 m2 4613 4813 197 >19.5 w2 4204 4404 197 >20.0 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.017 in the direction of the burst (Schlegel et al. 1998).
GCN 33115 table
GRB_name GRB221226B
GCN_number 33115
Detection_method Swift-BAT Det
ra 22.9030°
decl -41.5150°
Circular_text TITLE: GCN CIRCULAR NUMBER: 33115 SUBJECT: GRB 221226B Swift-BAT refined analysis DATE: 22/12/27 22:22:55 GMT FROM: Hans Krimm at NSF/NASA-GSFC S. Laha (GSFC/UMBC), S. D. Barthelmy (GSFC), S. B. Cenko (GSFC), H. A. Krimm (NSF), A. Y. Lien (U Tampa), C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Parsotan (GSFC/UMBC), T. Sakamoto (AGU), M. Stamatikos (OSU) (i.e. the Swift-BAT team): Using the data set from T-240 to T+963 sec from the recent telemetry downlink, we report further analysis of BAT GRB 221226B (trigger #1145959) (Cenko, et al., GCN Circ. 33108). The BAT ground-calculated position is RA, Dec = 22.903, -41.515 deg which is RA(J2000) = 01h 31m 36.7s Dec(J2000) = -41d 30' 52.5" with an uncertainty of 1.2 arcmin, (radius, sys+stat, 90% containment). The partial coding was 97%. The mask-weighted light curve shows a pulse of approximately 4 seconds total duration and some substructure. T90 (15-350 keV) is 3.44 +- 0.57 sec (estimated error including systematics). The time-averaged spectrum from T+0.22 to T+4.28 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.16 +- 0.13. The fluence in the 15-150 keV band is 5.4 +- 0.5 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from T+0.24 sec in the 15-150 keV band is 2.6 +- 0.3 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/1145959/BA/
GCN 33119 table
GRB_name GRB221226B
GCN_number 33119
Detection_method Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 33119 SUBJECT: GRB 221226B: LCOGT Optical Upper Limits DATE: 22/12/28 22:28:46 GMT FROM: Robert Strausbaugh at University of Minnesota R. Strausbaugh (University of Minnesota), A. Cucchiara (NASA) report on behalf of a larger collaboration: We observed the GRB 221226B (Cenko et al., GCN 33108) field with the LCOGT 1-meter Sinistro instrument at the South African Astronomical Observatory site, on December 27, from 19:40 to 20:07 UT (corresponding to 20.98 to 21.47 hours from the GRB trigger time) with the SDSS r and i filters. We performed a series of 3x300s exposures in each band. We do not detect any new sources in the XRT error region, in either band. The following upper limits are calculated using the SkyMapper catalog as reference: r > 20.75 i > 20.16 These magnitudes are not corrected for galactic extinction.