GRB110428A

This page lists all entries on GRB110428A in GRBweb

Summary Fermi GBM IPN Fermi LAT GCN 11982 GCN 11983 GCN 11984 GCN 11988 GCN 11989 GCN 12012 GCN 12017

Summary table
Variable Value Source
GRB_name_Fermi GRB110428388
T0 9:18:29.450 UTC GCN_circulars,Konus-Wind Det
ra 5.5926° Fermi_LAT
decl 64.8492° Fermi_LAT
pos_error 1.97e-03° Fermi_LAT
T90 5.632 s Fermi_GBM
T90_error 0.181 s Fermi_GBM
T90_start 9:18:33.094 UTC Fermi_GBM
fluence 2.16e-05 erg/cm² Fermi_GBM
fluence_error 1.54e-07 erg/cm² Fermi_GBM
T100 9.276 s
GBM_located False
mjd 55679.38784085648 GCN_circulars,Konus-Wind Det
Fermi GBM table
GRB_name_Fermi GRB110428388
trigger_name bn110428388
ra 5.3000°
decl 64.8000°
pos_error 2.53e+00°
datum 2011-04-28
t_trigger 9:18:30.406 UTC
T90 5.632 s
T90_error 0.181 s
T90_start 9:18:33.094 UTC
fluence 2.16e-05 erg/cm²
fluence_error 1.54e-07 erg/cm²
flux_1024 2.68e+01 erg/cm²/s
flux_1024_error 3.51e-01 erg/cm²/s
flux_1024_time 7.04e+00 erg/cm²/s
flux_64 3.22e+01 erg/cm²/s
flux_64_error 1.54e+00 erg/cm²/s
IPN table
GRB_name GRB110428A
ra 5.3000°
decl 64.8000°
pos_error 1.50e-01°
Fermi LAT table
GRB_name_Fermi GRB110428388
GRB_name GRB110428A
MET 325675112.0
datum 2011-04-28
t_trigger 9:18:30 UTC
ra 5.5926°
decl 64.8492°
pos_error 1.97e-03°
GCN 11982 table
GRB_name GRB110428A
GCN_number 11982
Detection_method Fermi LAT Det
Circular_text TITLE: GCN CIRCULAR NUMBER: 11982 SUBJECT: GRB 110428A: Fermi-LAT Detection DATE: 11/04/29 01:54:25 GMT FROM: Vlasios Vasileiou at LUPM/Fermi-LAT V. Vasileiou (CNRS/IN2P3/LUPM), N. Omodei (Stanford University), D. Kocevski (SLAC), F. Piron (CNRS/IN2P3/LUPM), on behalf of the Fermi Large Area Telescope collaboration. Based on an on-ground analysis, the Large Area Telescope (LAT), on-board the Fermi Gamma-ray Space Telescope, detected high energy emission extending up to ~3 GeV from the GBM-detected GRB 110428A (trigger 325675112). The detected emission lasts up to ~200 seconds. We obtain a localization of RA, DEC (J2000 deg) = 5.30, 64.80 (00h 21m 12s, 64d 47' 42.0"), (galactic l=119.71 deg, b=2.11 deg), with a statistical error of 0.15 deg (68% CL), compatible with the GBM localization. The burst was initially at an angle of ~34 degrees to the LAT boresight and triggered an autonomous repoint of the spacecraft. According to preliminary spectral fits, the spectral index of the detected emission is -1.5+-0.1 (68% CL) at E>100MeV energies. Further analysis is ongoing. The Fermi LAT point of contact for this burst is Vlasios Vasileiou (vlasios.vasileiou@lupm.in2p3.fr). The Fermi LAT is a pair conversion telescope designed to cover the energy band from 20 MeV to greater than 300 GeV. It is the product of an international collaboration between NASA and DOE in the U.S. and many scientific institutions across France, Italy, Japan and Sweden.
GCN 11983 table
GRB_name GRB110428A
GCN_number 11983
Detection_method Konus-Wind Det
t_trigger 9:18:29.450 UTC
Circular_text TITLE: GCN CIRCULAR NUMBER: 11983 SUBJECT: Konus-Wind observation of GRB 110428A DATE: 11/04/29 13:56:48 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 bright GRB 110428A localized by Fermi-LAT (Vasileiou et al., GCN 11982) triggered Konus-Wind at T0=33509.450 s UT (09:18:29.450). The burst light curve shows two pulses started at ~T0-9 s with a total duration of ~15 s. As observed by Konus-Wind the burst had a fluence of 2.70(-0.16, +0.15)x10^-5 erg/cm2, and a 64-ms peak flux measured from T0+1.296 s of 8.47(-1.17, +1.18)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+13.568 s) can be fitted (in the 20 keV - 2 MeV range) by the GRB (Band) model for which: the low-energy photon index is alpha = -0.30(-0.11, +0.12), the high energy photon index beta = -3.00(-0.58, +0.27), the peak energy Ep = 184(-10, +12) keV (chi2 = 78.2/59 dof). The spectrum at the maximum count rate (measured from T0+0.256 to T0+1.536 s) can be fitted (in the 20 keV - 2 MeV range) by a power law with exponential cutoff model: dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep) with alpha = -0.19(-0.13, +0.14), and Ep = 257(-16, +17) keV (chi2 = 63.1/52 dof). Fitting by GRB (Band) model yields the same alpha and Ep, and an upper limit on the high energy photon index: beta < -3.5 (chi2 = 63.1/51 dof). All the quoted errors are at the 90% confidence level. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB110428_T33509/
GCN 11984 table
GRB_name GRB110428A
GCN_number 11984
Detection_method Swift-XRT Other
ra 0.0000°
decl 64.0000°
Circular_text TITLE: GCN CIRCULAR NUMBER: 11984 SUBJECT: GRB 110428A : Swift-XRT observations DATE: 11/04/29 14:46:44 GMT FROM: Andrea Melandri at INAF-OAB A. Melandri, P. D'Avanzo, R. Margutti (INAF-OAB), B. Sbarufatti (INAF- OAB/IASFPA) and M. Stamatikos (OSU/NASA/GSFC) report on behalf of the Swift Team: At 00:47 UT, April 29th, 2011, Swift began a Target of Opportunity observation of the Fermi GBM/LAT discovered burst GRB 110428A (Vasileiou et al. GCN 11982), ~55.6 ks after the Fermi detection. In 4.8 ks of Photon Counting mode data, we detect two sources within the Fermi-LAT error circle (0.15 deg radius, 68% CL) at the following positions: Source 1: RA(J2000): 00 21 50.47 Dec(J2000): +64 48 52.4 with an uncertainty of 4.6 arcsec. Source 2: RA(J2000): 00 22 22.22 Dec(J2000): +64:50:57.1 with an uncertainty of 7.1 arcsec. Uncertainty radii are given at 90% containment. We note that the position of Source 1 is consistent with a known ROSAT source (1RXS J002150.5+644850) also present in the DSS. Source 2 is an uncatalogued object. The two sources have a count rate of about (1.2e-2 +/- 1.8e-3) and (2.9e-3 +/- 9.1e-4) cts/s, respectively. It is not possible to determine whether these sources are fading given the current statistics. Further Swift-XRT observations of the field are planned. We encourage ground-based follow-up observations. This circular is an official product of the Swift-XRT team.
GCN 11988 table
GRB_name GRB110428A
GCN_number 11988
Detection_method Suzaku WAM Det
Circular_text TITLE: GCN CIRCULAR NUMBER: 11988 SUBJECT: GRB 110428A: Suzaku WAM observation of the prompt emission DATE: 11/05/02 10:21:42 GMT FROM: Makoto Tashiro at Saitama U/Swift W. Iwakiri, Y. Terada, M. Tashiro, K. Takahara, T. Yasuda (Saitama U.), T. Uehara, Y. Hanabata, T. Takahashi, Y. Fukazawa (Hiroshima U.), N. Vasquez (Tokyo Tech.) K. Yamaoka (Aoyama Gakuin U.), M. Ohno, M. Kokubun, T. Takahashi (ISAS/JAXA), S. Sugita (Nagoya U.), Y. E. Nakagawa (Waseda U.), N. Ohmori, M. Akiyama, M. Yamauchi (Univ. of Miyazaki), Y. Urata, P. Tsai (NCU), K. Nakazawa, K. Makishima (Univ. of Tokyo), on behalf of the Suzaku WAM team, report: The long bright GRB 110428A localized by Fermi-LAT (Vasileiou et al., GCN 11982) was observed the Suzaku Wide-band All-sky Monitor (WAM) which covers an energy range of 50 keV - 5 MeV at 09:18:30 UT (=T0). The observed light curve shows double-peaked structure starting at T0-2s, ending at T0+10 s with a duration (T90) of about 5 seconds. The fluence in 100 - 1000 keV was 1.31 (-0.43, +2.03) x 10^-5 erg/cm^2. The 1-s peak flux measured from T0+4 s was 9.91 (-0.34, +1.19) photons/cm^2/s in the same energy range. Preliminary result shows that the time-averaged spectrum from T0-2s to T0+10s is well fitted by a power-law with exponential cutoff model : dN/dE ~ E^{-alpha} * exp(-(2-alpha)*E/Epeak) with alpha 1.11 (-0.22, +0.19), and Epeak 195.5 (-14.4, +15.9) keV (chi2/d.o.f. = 15.8/20). All the quoted errors are at statistical 90% confidence level.
GCN 11989 table
GRB_name GRB110428A
GCN_number 11989
Detection_method Swift-XRT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 11989 SUBJECT: GRB 110428A : X-ray afterglow confirmation DATE: 11/05/02 19:15:40 GMT FROM: Andrea Melandri at Liverpool John Moores U A. Melandri, P. D'Avanzo, R. Margutti (INAF-OAB), B. Sbarufatti (INAF- OAB/IASFPA) report on behalf of the Swift Team: Swift continued to monitor the field of GRB 110428A (Vasileiou et al., GCN 11982) in two different observations carried out on April 29th and May 1st, 2011. In the final 18.49 ks of data (at a mean T-T0 = 2.07 days after the burst event) we still detect Source #1 reported by Melandri et al. (GCN 11984) with count rate of (1.6e-2 +/- 1.1e-3) cts/s, consistent with a constant flux for this source. Source #2 is no longer detected with a 3 sigma upper limit of 1.4e-3 cts/s. The probability for this source of having a constant flux is 8e-6. This is evidence of the fading of Source #2 with respect to the XRT observation reported in Melandri et al. (GCN 11984). Therefore we consider Source #2 as the X-ray afterglow of GRB 110428A. This circular is an official product of the Swift-XRT team.
GCN 12012 table
GRB_name GRB110428A
GCN_number 12012
Detection_method Fermi GBM Det
t_trigger 9:18:30.410 UTC
Circular_text TITLE: GCN CIRCULAR NUMBER: 12012 SUBJECT: GRB 110428A: Fermi-GBM observation DATE: 11/05/06 18:25:50 GMT FROM: David Tierney at UCD D. Tierney (UCD) and G. Fitzpatrick (UCD) report on behalf of the Fermi GBM Team: "At 09:18:30.41 UT on 28 April 2011, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 110428A (trigger 325675112 / 110428388) which was also detected by the Fermi-LAT (V. Vasileiou et al. 2011, GCN 11982), Konus-Wind (S. Golenetskii et al. 2011, GCN 11983), and Suzaku WAM (W. Iwakiri et al. 2011, GCN 11988). The GBM on-ground location is consistent with the Swift-XRT position (A. Melandri et al. 2011, GCN 11984). The GBM light curve consists of a single pulse with a duration (T90) of 5.6 +/- 0.2 s (50-300 keV). The time-averaged spectrum from T0+1.8 s to T0+9 s is best fit by a Band function with Epeak = 175.60 (+3.95/-3.82) keV, alpha = -0.20 (+0.03/-0.03), and beta = -2.88 (+0.10/-0.12) (C-Stat 559.66 for 482 d.o.f.). The event fluence (10-1000 keV) in this time interval is (2.27 +/- 0.03)E-05 erg/cm^2. The 1-sec peak photon flux measured starting from T0+7 s in the 10-1000 keV band is 26.8 +/- 0.4 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."
GCN 12017 table
GRB_name GRB110428A
GCN_number 12017
Detection_method Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 12017 SUBJECT: Radio observations of GRB 110428A with the EVLA DATE: 11/05/19 19:33:20 GMT FROM: Poonam Chandra at Royal Mil. College Canada "Poonam Chandra (RMC), Dale A. Frail (NRAO), S. Bradley Cenko (Berkeley), Fiona Harrison (Caltech) and Srinivas Kulkarni (Caltech) report: We observed the Fermi burst GRB 110428A (Vasileiou et al. GCN 11982) with the Expanded Very Large Array (EVLA) at various radio frequencies between April 30 and May 13. We did not detect any significant radio source within the 7.1" error circle of source 2 (Melandri et al. GCN 11984). Below are the details and 3-sigma upper limits from our observations: Epoch Frequency 3-sigma upper limit Apr 30.45 UT 4.5 GHz 93 uJy Apr 30.45 UT 7.9 GHz 66 uJy May 3.50 UT 4.5 GHz 66 uJy May 3.50 UT 7.9 GHz 54 uJy May 6.74 UT 4.5 GHz 87 uJy May 6.74 UT 7.9 GHz 60 uJy May 10.48 UT 22.45 GHz 240 uJy May 13.41 UT 8.33 GHz 35 uJy We thank the EVLA staff for scheduling our observations so promptly. The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc."