SEARCHING FOR NEEDLES IN HAYSTACKS-LOOKING FOR GAMMA-RAY BURST γ-RAYS WITH THE FERMI/LAT DETECTOR

被引:11
作者
Akerlof, C. W. [1 ]
Zheng, W. [1 ]
Pandey, S. B. [1 ,2 ]
Mckay, T. A. [1 ]
机构
[1] Univ Michigan, Randall Lab Phys, Ann Arbor, MI 48109 USA
[2] Aryabhatta Res Inst Observat Sci, Manora Peak 263129, Nainital, India
关键词
gamma-ray burst: general; GEV EMISSION; HIGH-ENERGY; COMPONENT;
D O I
10.1088/0004-637X/726/1/22
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
Since the launch of the Fermi Gamma-ray Space Telescope on 2008 June 11, 55 gamma-ray bursts (GRBs) have been observed at coordinates that fall within 66 degrees of the Fermi Large Area Telescope (LAT) boresight with precise localizations provided by the NASA Swift mission or other satellites. Imposing selection cuts to exclude low Galactic latitudes and high zenith angles reduces the sample size to 41. Using matched filter techniques, the Fermi/LAT photon data for these fields have been examined for evidence of bursts that have so far evaded detection at energies above 100 MeV. Following comparisons with similar random background fields, two events, GRB 080905A and GRB 091208B, stand out as excellent candidates for such an identification. After excluding the six bright bursts previously reported by the LAT team, the remaining 35 events exhibit an excess of LAT "diffuse" photons with a statistical significance greater than 2 sigma, independent of the matched filter analysis. After accounting for the total number of photons in the well-localized fields and including estimates of detection efficiency, one concludes that somewhere in the range of 11%-19% of all GRBs within the LAT field of view illuminate the detector with two or more energetic photons. These are the most stringent estimates of the high-energy photon content of GRBs to date. The two new events associated with high-energy photon emission have similar ratios of high- to low-energy fluences as observed previously. This separates them from bursts with similar low-energy fluences by a factor of 10, suggesting a distinct class of events rather than a smooth continuum.
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共 26 条
[1]   FERMI DETECTION DELAYED GeV EMISSION FROM THE SHORT GAMMA-RAY BURST 081024B [J].
Abdo, A. A. ;
Ackermann, M. ;
Ajello, M. ;
Asano, K. ;
Atwood, W. B. ;
Axelsson, M. ;
Baldini, L. ;
Ballet, J. ;
Barbiellini, G. ;
Bastieri, D. ;
Baughman, B. M. ;
Bechtol, K. ;
Bellazzini, R. ;
Berenji, B. ;
Bhat, P. N. ;
Bissaldi, E. ;
Blandford, R. D. ;
Bloom, E. D. ;
Bonamente, E. ;
Borgland, A. W. ;
Bouvier, A. ;
Bregeon, J. ;
Brez, A. ;
Briggs, M. S. ;
Brigida, M. ;
Bruel, P. ;
Burgess, J. M. ;
Burnett, T. H. ;
Buson, S. ;
Caliandro, G. A. ;
Cameron, R. A. ;
Caraveo, P. A. ;
Carrigan, S. ;
Casandjian, J. M. ;
Cecchi, C. ;
Celik, Oe ;
Chaplin, V. ;
Charles, E. ;
Chekhtman, A. ;
Chiang, J. ;
Ciprini, S. ;
Claus, R. ;
Cohen-Tanugi, J. ;
Cominsky, L. R. ;
Connaughton, V. ;
Conrad, J. ;
Cutini, S. ;
Dermer, C. D. ;
de Angelis, A. ;
de Palma, F. .
ASTROPHYSICAL JOURNAL, 2010, 712 (01) :558-564
[2]   A limit on the variation of the speed of light arising from quantum gravity effects [J].
Abdo, A. A. ;
Ackermann, M. ;
Ajello, M. ;
Asano, K. ;
Atwood, W. B. ;
Axelsson, M. ;
Baldini, L. ;
Ballet, J. ;
Barbiellini, G. ;
Baring, M. G. ;
Bastieri, D. ;
Bechtol, K. ;
Bellazzini, R. ;
Berenji, B. ;
Bhat, P. N. ;
Bissaldi, E. ;
Bloom, E. D. ;
Bonamente, E. ;
Bonnell, J. ;
Borgland, A. W. ;
Bouvier, A. ;
Bregeon, J. ;
Brez, A. ;
Briggs, M. S. ;
Brigida, M. ;
Bruel, P. ;
Burgess, J. M. ;
Burnett, T. H. ;
Caliandro, G. A. ;
Cameron, R. A. ;
Caraveo, P. A. ;
Casandjian, J. M. ;
Cecchi, C. ;
Celik, Oe ;
Chaplin, V. ;
Charles, E. ;
Cheung, C. C. ;
Chiang, J. ;
Ciprini, S. ;
Claus, R. ;
Cohen-Tanugi, J. ;
Cominsky, L. R. ;
Connaughton, V. ;
Conrad, J. ;
Cutini, S. ;
Dermer, C. D. ;
de Angelis, A. ;
de Palma, F. ;
Digel, S. W. ;
Dingus, B. L. .
NATURE, 2009, 462 (7271) :331-334
[3]   FERMI OBSERVATIONS OF GRB 090902B: A DISTINCT SPECTRAL COMPONENT IN THE PROMPT AND DELAYED EMISSION [J].
Abdo, A. A. ;
Ackermann, M. ;
Ajello, M. ;
Asano, K. ;
Atwood, W. B. ;
Axelsson, M. ;
Baldini, L. ;
Ballet, J. ;
Barbiellini, G. ;
Baring, M. G. ;
Bastieri, D. ;
Bechtol, K. ;
Bellazzini, R. ;
Berenji, B. ;
Bhat, P. N. ;
Bissaldi, E. ;
Blandford, R. D. ;
Bloom, E. D. ;
Bonamente, E. ;
Borgland, A. W. ;
Bouvier, A. ;
Bregeon, J. ;
Brez, A. ;
Briggs, M. S. ;
Brigida, M. ;
Bruel, P. ;
Burgess, J. M. ;
Burrows, D. N. ;
Buson, S. ;
Caliandro, G. A. ;
Cameron, R. A. ;
Caraveo, P. A. ;
Casandjian, J. M. ;
Cecchi, C. ;
Celik, Oe. ;
Chekhtman, A. ;
Cheung, C. C. ;
Chiang, J. ;
Ciprini, S. ;
Claus, R. ;
Cohen-Tanugi, J. ;
Cominsky, L. R. ;
Connaughton, V. ;
Conrad, J. ;
Cutini, S. ;
d'Elia, V. ;
Dermer, C. D. ;
de Angelis, A. ;
de Palma, F. ;
Digel, S. W. .
ASTROPHYSICAL JOURNAL LETTERS, 2009, 706 (01) :L138-L144
[4]   Fermi Observations of High-Energy Gamma-Ray Emission from GRB 080916C [J].
Abdo, A. A. ;
Ackermann, M. ;
Arimoto, M. ;
Asano, K. ;
Atwood, W. B. ;
Axelsson, M. ;
Baldini, L. ;
Ballet, J. ;
Band, D. L. ;
Barbiellini, G. ;
Baring, M. G. ;
Bastieri, D. ;
Battelino, M. ;
Baughman, B. M. ;
Bechtol, K. ;
Bellardi, F. ;
Bellazzini, R. ;
Berenji, B. ;
Bhat, P. N. ;
Bissaldi, E. ;
Blandford, R. D. ;
Bloom, E. D. ;
Bogaert, G. ;
Bogart, J. R. ;
Bonamente, E. ;
Bonnell, J. ;
Borgland, A. W. ;
Bouvier, A. ;
Bregeon, J. ;
Brez, A. ;
Briggs, M. S. ;
Brigida, M. ;
Bruel, P. ;
Burnett, T. H. ;
Burrows, D. ;
Busetto, G. ;
Caliandro, G. A. ;
Cameron, R. A. ;
Caraveo, P. A. ;
Casandjian, J. M. ;
Ceccanti, M. ;
Cecchi, C. ;
Celotti, A. ;
Charles, E. ;
Chekhtman, A. ;
Cheung, C. C. ;
Chiang, J. ;
Ciprini, S. ;
Claus, R. ;
Cohen-Tanugi, J. .
SCIENCE, 2009, 323 (5922) :1688-1693
[5]   FERMI OBSERVATIONS OF GRB 090510: A SHORT-HARD GAMMA-RAY BURST WITH AN ADDITIONAL, HARD POWER-LAW COMPONENT FROM 10 keV TO GeV ENERGIES [J].
Ackermann, M. ;
Asano, K. ;
Atwood, W. B. ;
Axelsson, M. ;
Baldini, L. ;
Ballet, J. ;
Barbiellini, G. ;
Baring, M. G. ;
Bastieri, D. ;
Bechtol, K. ;
Bellazzini, R. ;
Berenji, B. ;
Bhat, P. N. ;
Bissaldi, E. ;
Blandford, R. D. ;
Bloom, E. D. ;
Bonamente, E. ;
Borgland, A. W. ;
Bouvier, A. ;
Bregeon, J. ;
Brez, A. ;
Briggs, M. S. ;
Brigida, M. ;
Bruel, P. ;
Buson, S. ;
Caliandro, G. A. ;
Cameron, R. A. ;
Caraveo, P. A. ;
Carrigan, S. ;
Casandjian, J. M. ;
Cecchi, C. ;
Celik, Oe. ;
Charles, E. ;
Chiang, J. ;
Ciprini, S. ;
Claus, R. ;
Cohen-Tanugi, J. ;
Connaughton, V. ;
Conrad, J. ;
Dermer, C. D. ;
de Palma, F. ;
Dingus, B. L. ;
do Couto e Silva, E. ;
Drell, P. S. ;
Dubois, R. ;
Dumora, D. ;
Farnier, C. ;
Favuzzi, C. ;
Fegan, S. J. ;
Finke, J. .
ASTROPHYSICAL JOURNAL, 2010, 716 (02) :1178-1190
[6]  
AKERLOF CW, 2007, ARXIVASTROPH0702295V
[7]   THE LARGE AREA TELESCOPE ON THE FERMI GAMMA-RAY SPACE TELESCOPE MISSION [J].
Atwood, W. B. ;
Abdo, A. A. ;
Ackermann, M. ;
Althouse, W. ;
Anderson, B. ;
Axelsson, M. ;
Baldini, L. ;
Ballet, J. ;
Band, D. L. ;
Barbiellini, G. ;
Bartelt, J. ;
Bastieri, D. ;
Baughman, B. M. ;
Bechtol, K. ;
Bederede, D. ;
Bellardi, F. ;
Bellazzini, R. ;
Berenji, B. ;
Bignami, G. F. ;
Bisello, D. ;
Bissaldi, E. ;
Blandford, R. D. ;
Bloom, E. D. ;
Bogart, J. R. ;
Bonamente, E. ;
Bonnell, J. ;
Borgland, A. W. ;
Bouvier, A. ;
Bregeon, J. ;
Brez, A. ;
Brigida, M. ;
Bruel, P. ;
Burnett, T. H. ;
Busetto, G. ;
Caliandro, G. A. ;
Cameron, R. A. ;
Caraveo, P. A. ;
Carius, S. ;
Carlson, P. ;
Casandjian, J. M. ;
Cavazzuti, E. ;
Ceccanti, M. ;
Cecchi, C. ;
Charles, E. ;
Chekhtman, A. ;
Cheung, C. C. ;
Chiang, J. ;
Chipaux, R. ;
Cillis, A. N. ;
Ciprini, S. .
ASTROPHYSICAL JOURNAL, 2009, 697 (02) :1071-1102
[8]   PROSPECTS FOR GRB SCIENCE WITH THE FERMI LARGE AREA TELESCOPE [J].
Band, D. L. ;
Axelsson, M. ;
Baldini, L. ;
Barbiellini, G. ;
Baring, M. G. ;
Bastieri, D. ;
Battelino, M. ;
Bellazzini, R. ;
Bissaldi, E. ;
Bogaert, G. ;
Bonnell, J. ;
Chiang, J. ;
Cohen-Tanugi, J. ;
Connaughton, V. ;
Cutini, S. ;
de Palma, F. ;
Dingus, B. L. ;
do Couto e Silva, E. ;
Fishman, G. ;
Galli, A. ;
Gehrels, N. ;
Giglietto, N. ;
Granot, J. ;
Guiriec, S. ;
Hughes, R. E. ;
Kamae, T. ;
Komin, N. ;
Kuehn, F. ;
Kuss, M. ;
Longo, F. ;
Lubrano, P. ;
Kippen, R. M. ;
Mazziotta, M. N. ;
McEnery, J. E. ;
McGlynn, S. ;
Moretti, E. ;
Nakamori, T. ;
Norris, J. P. ;
Ohno, M. ;
Olivo, M. ;
Omodei, N. ;
Pelassa, V. ;
Piron, F. ;
Preece, R. ;
Razzano, M. ;
Russell, J. J. ;
Ryde, F. ;
Parkinson, P. M. Saz ;
Scargle, J. D. ;
Sgro, C. .
ASTROPHYSICAL JOURNAL, 2009, 701 (02) :1673-1694
[9]  
BHAT PN, 2008, 8550 GCN
[10]  
BISSALDI E, 2008, 8204 GCN