DETECTION OF A SPECTRAL BREAK IN THE EXTRA HARD COMPONENT OF GRB 090926A

Ackermann M, Ajello M, Asano K, Axelsson M, Baldini L, Ballet J, Barbiellini G, Baring MG, Bastieri D, Bechtol K, Bellazzini R, Berenji B, Bhat PN, Bissaldi E, Blandford RD, Bonamente E, Borgland AW, Bouvier A, Bregeon J, Brez A, Briggs MS, Brigida M, Bruel P, Buehler R, Buson S, Caliandro GA, Cameron RA, Caraveo PA, Carrigan S, Casandjian JM, Cecchi C, Celik O, Chaplin V, Charles E, Chekhtman A, Chiang J, Ciprini S, Claus R, Cohen-Tanugi J, Connaughton V, Conrad J, Cutini S, Dermer CD, De Angelis A, De Palma F, Dingus BL, Silva EDCE, Drell PS, Dubois R, Favuzzi C, Fegan SJ, Ferrara EC, Focke WB, Frailis M, Fukazawa Y, Funk S, Fusco P, Gargano F, Gasparrini D, Gehrels N, Germani S, Giglietto N, Giordano F, Giroletti M, Glanzman T, Godfrey G, Goldstein A, Granot J, Greiner J, Grenier IA, Grove JE, Guiriec S, Hadasch D, Hanabata Y, Harding AK, Hayashi K, Hayashida M, Hays E, Horan D, Hughes RE, Itoh R, Johannesson G, Johnson AS, Johnson WN, Kamae T, Katagiri H, Kataoka J, Kippen RM, Knoedlseder J, Kocevski D, Kouveliotou C, Kuss MW, Lande J, Latronico L, Lee SH, Garde ML, Longo F, Loparco F, Lovellette MN, Lubrano P, Makeev A, Mazziotta MN, Mcbreen S, Mcenery JE, Mcglynn S, Meegan C, Mehault J, Meszaros P, Michelson PF, Mizuno T, Monte C, Monzani ME, Moretti E, Morselli A, Moskalenko IV, Murgia S, Nakajima H, Nakamori T, Naumann-Godo M, Nishino S, Nolan PL, Norris JP, Nuss E, Ohno M, Ohsugi T, Okumura A, Omodei N, Orlando E, Ormes JF, Ozaki M, Paciesas WS, Paneque D, Panetta JH, Parent D, Pelassa V, Pepe M, Pesce-Rollins M, Petrosian V, Piron F, Porter TA, Preece R, Racusin JL, Raino S, Rando R, Rau A, Razzano M, Razzaque S, Reimer A, Reimer O, Reposeur T, Reyes LC, Ripken J, Ritz S, Roth M, Ryde F, Sadrozinski HFW, Sander A, Scargle JD, Strickman MS, Suson DJ, Tajima H, Takahashi HH, Tanaka T, Tanaka Y, Thayer JB, Thayer JG, Tibaldo L, Tierney D, Toma K, Torres DF, Tosti G, Tramacere A, Uchiyama Y, Uehara T, Usher TL, Vandenbroucke J, Van Der Horst AJ, Vasileiou V, Vilchez N, Vitale V, Von Kienlin A, Waite AP, Wang P, Wilson-Hodge C, Winer BL, Wood KS, Wu XF, Yamazaki R, Yang Z, Ylinen T, Ziegler M (2011)


Publication Type: Journal article

Publication year: 2011

Journal

Book Volume: 729

Journal Issue: 2

DOI: 10.1088/0004-637X/729/2/114

Abstract

We report on the observation of the bright, long gamma-ray burst, GRB 090926A, by the Gamma-ray Burst Monitor and Large Area Telescope (LAT) instruments on board the Fermi Gamma-ray Space Telescope. GRB 090926A shares several features with other bright LAT bursts. In particular, it clearly shows a short spike in the light curve that is present in all detectors that see the burst, and this in turn suggests that there is a common region of emission across the entire Fermi energy range. In addition, while a separate high-energy power-law component has already been observed in other gamma-ray bursts, here we report for the first time the detection with good significance of a high-energy spectral break (or cutoff) in this power-law component around 1.4 GeV in the time-integrated spectrum. If the spectral break is caused by opacity to electron-positron pair production within the source, then this observation allows us to compute the bulk Lorentz factor for the outflow, rather than a lower limit.

Authors with CRIS profile

Involved external institutions

Stanford University Tokyo Institute of Technology Stockholm University / Stockholms universitet National Institute for Nuclear Physics / Istituto Nazionale di Fisica Nucleare (INFN) University of Alabama in Huntsville (UAH) Max-Planck-Institut für extraterrestrische Physik (MPE) / Max Planck Institute for Extraterrestrial Physics University of Bari Aldo Moro / Università degli Studi di Bari Aldo Moro École Polytechnique - Université Paris-Saclay University of Paris 6 - Pierre et Marie Curie / Université Paris VI Pierre et Marie Curie (UPMC) AlbaNova University Centre / Kungliga Tekniska Högskolan AlbaNova Universitetscentrum Italian Space Agency / Agenzia Spaziale Italiana (ASI) U.S. Naval Research Laboratory University of Udine / Università degli Studi di Udine Los Alamos National Laboratory National Aeronautics and Space Administration (NASA) Hiroshima University / 広島大学 Rice University University of Hertfordshire Institut d'Estudis Espacials de Catalunya (IEEC) National Institute for Astrophysics / Istituto Nazionale Astrofisica (INAF) University of Padua / Universita degli Studi di Padova University of Montpellier / Université Montpellier Università degli Studi di Perugia Ohio State University Waseda University / 早稲田大学 The National Space Science & Technology Center Centre d’étude spatiale des rayonnements (CESR) University of Denver Pennsylvania State University (Penn State) Japan Aerospace eXploration Agency (JAXA) University of Washington Purdue University Northwest / Purdue University Calumet University of California, Santa Cruz (UC Santa Cruz, UCSC) Université Bordeaux 1, Sciences et Technologies University of Chicago University College Dublin (UCD) Aoyama-Gakuin-University / 青山学院大学

How to cite

APA:

Ackermann, M., Ajello, M., Asano, K., Axelsson, M., Baldini, L., Ballet, J.,... Ziegler, M. (2011). DETECTION OF A SPECTRAL BREAK IN THE EXTRA HARD COMPONENT OF GRB 090926A. Astrophysical Journal, 729(2). https://doi.org/10.1088/0004-637X/729/2/114

MLA:

Ackermann, Markus, et al. "DETECTION OF A SPECTRAL BREAK IN THE EXTRA HARD COMPONENT OF GRB 090926A." Astrophysical Journal 729.2 (2011).

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