Fermi observations of GRB 090510: A short-hard gamma-ray burst with an additional, hard power-law component from 10 keV to GeV energies

M. Ackermann; K. Asano; W. B. Atwood; M. Axelsson; L. Baldini; J. Ballet; G. Barbiellini; M. G. Baring; D. Bastieri; K. Bechtol; R. Bellazzini; B. Berenji; P. N. Bhat; E. Bissaldi; R. D. Blandford; E. D. Bloom; E. Bonamente; A. W. Borgland; A. Bouvier; J. Bregeon; A. Brez; M. S. Briggs; M. Brigida; P. Bruel; S. Buson; G. A. Caliandro; R. A. Cameron; P. A. Caraveo; S. Carrigan; J. M. Casandjian; C. Cecchi; Ö Çelik; E. Charles; J. Chiang; S. Ciprini; R. Claus; J. Cohen-Tanugi; V. Connaughton; J. Conrad; C. D. Dermer; F. De Palma; B. L. Dingus; E. Do Couto E Silva; P. S. Drell; R. Dubois; D. Dumora; C. Farnier; C. Favuzzi; S. J. Fegan; J. Finke; W. B. Focke; M. Frailis; Y. Fukazawa; P. Fusco; F. Gargano; D. Gasparrini; N. Gehrels; S. Germani; N. Giglietto; F. Giordano; T. Glanzman; G. Godfrey; J. Granot; I. A. Grenier; M. H. Grondin; J. E. Grove; S. Guiriec; D. Hadasch; A. K. Harding; E. Hays; D. Horan; R. E. Hughes; G. Jóhannesson; W. N. Johnson; T. Kamae; H. Katagiri; J. Kataoka; N. Kawai; R. M. Kippen; J. Knödlseder; D. Kocevski; C. Kouveliotou; M. Kuss; J. Lande; L. Latronico; M. Lemoine-Goumard; M. Llena Garde; F. Longo; F. Loparco; B. Lott; M. N. Lovellette; P. Lubrano; A. Makeev; M. N. Mazziotta; J. E. McEnery; S. McGlynn; C. Meegan; P. Mészros; P. F. Michelson; W. Mitthumsiri; T. Mizuno; A. A. Moiseev; C. Monte; M. E. Monzani; E. Moretti; A. Morselli; I. V. Moskalenko; S. Murgia; H. Nakajima; T. Nakamori; P. L. Nolan; J. P. Norris; E. Nuss; M. Ohno; T. Ohsugi; N. Omodei; E. Orlando; J. F. Ormes; M. Ozaki; W. S. Paciesas; D. Paneque; J. H. Panetta; D. Parent; V. Pelassa; M. Pepe; M. Pesce-Rollins; F. Piron; R. Preece; S. Rainò; R. Rando; M. Razzano; S. Razzaque; A. Reimer; S. Ritz; A. Y. Rodriguez; M. Roth; F. Ryde; H. F.W. Sadrozinski; A. Sander; J. D. Scargle; T. L. Schalk; C. Sgrò; E. J. Siskind; P. D. Smith; G. Spandre; P. Spinelli; M. Stamatikos; F. W. Stecker; M. S. Strickman; D. J. Suson; H. Tajima; H. Takahashi; T. Takahashi; T. Tanaka; J. B. Thayer; J. G. Thayer; D. J. Thompson; L. Tibaldo; K. Toma; D. F. Torres; G. Tosti; A. Tramacere; Y. Uchiyama; T. Uehara; T. L. Usher; A. J. Van Der Horst; V. Vasileiou; N. Vilchez; V. Vitale; A. Von Kienlin; A. P. Waite; P. Wang; C. Wilson-Hodge; B. L. Winer; X. F. Wu; R. Yamazaki; Z. Yang; T. Ylinen; M. Ziegler

doi:10.1088/0004-637X/716/2/1178

Fermi observations of GRB 090510: A short-hard gamma-ray burst with an additional, hard power-law component from 10 keV to GeV energies

M. Ackermann, K. Asano, W. B. Atwood, M. Axelsson, L. Baldini, J. Ballet, G. Barbiellini, M. G. Baring, D. Bastieri, K. Bechtol, R. Bellazzini, B. Berenji, P. N. Bhat, E. Bissaldi, R. D. Blandford, E. D. Bloom, E. Bonamente, A. W. Borgland, A. Bouvier, J. BregeonA. Brez, M. S. Briggs, M. Brigida, P. Bruel, S. Buson, G. A. Caliandro, R. A. Cameron, P. A. Caraveo, S. Carrigan, J. M. Casandjian, C. Cecchi, Ö Çelik, E. Charles, J. Chiang, S. Ciprini, R. Claus, J. Cohen-Tanugi, V. Connaughton, J. Conrad, C. D. Dermer, F. De Palma, B. L. Dingus, E. Do Couto E Silva, P. S. Drell, R. Dubois, D. Dumora, C. Farnier, C. Favuzzi, S. J. Fegan, J. Finke, W. B. Focke, M. Frailis, Y. Fukazawa, P. Fusco, F. Gargano, D. Gasparrini, N. Gehrels, S. Germani, N. Giglietto, F. Giordano, T. Glanzman, G. Godfrey, J. Granot, I. A. Grenier, M. H. Grondin, J. E. Grove, S. Guiriec, D. Hadasch, A. K. Harding, E. Hays, D. Horan, R. E. Hughes, G. Jóhannesson, W. N. Johnson, T. Kamae, H. Katagiri, J. Kataoka, N. Kawai, R. M. Kippen, J. Knödlseder, D. Kocevski, C. Kouveliotou, M. Kuss, J. Lande, L. Latronico, M. Lemoine-Goumard, M. Llena Garde, F. Longo, F. Loparco, B. Lott, M. N. Lovellette, P. Lubrano, A. Makeev, M. N. Mazziotta, J. E. McEnery, S. McGlynn, C. Meegan, P. Mészros, P. F. Michelson, W. Mitthumsiri, T. Mizuno, A. A. Moiseev, C. Monte, M. E. Monzani, E. Moretti, A. Morselli, I. V. Moskalenko, S. Murgia, H. Nakajima, T. Nakamori, P. L. Nolan, J. P. Norris, E. Nuss, M. Ohno, T. Ohsugi, N. Omodei, E. Orlando, J. F. Ormes, M. Ozaki, W. S. Paciesas, D. Paneque, J. H. Panetta, D. Parent, V. Pelassa, M. Pepe, M. Pesce-Rollins, F. Piron, R. Preece, S. Rainò, R. Rando, M. Razzano, S. Razzaque, A. Reimer, S. Ritz, A. Y. Rodriguez, M. Roth, F. Ryde, H. F.W. Sadrozinski, A. Sander, J. D. Scargle, T. L. Schalk, C. Sgrò, E. J. Siskind, P. D. Smith, G. Spandre, P. Spinelli, M. Stamatikos, F. W. Stecker, M. S. Strickman, D. J. Suson, H. Tajima, H. Takahashi, T. Takahashi, T. Tanaka, J. B. Thayer, J. G. Thayer, D. J. Thompson, L. Tibaldo, K. Toma, D. F. Torres, G. Tosti, A. Tramacere, Y. Uchiyama, T. Uehara, T. L. Usher, A. J. Van Der Horst, V. Vasileiou, N. Vilchez, V. Vitale, A. Von Kienlin, A. P. Waite, P. Wang, C. Wilson-Hodge, B. L. Winer, X. F. Wu, R. Yamazaki, Z. Yang, T. Ylinen, M. Ziegler

Research output: Contribution to journal › Article › peer-review

Abstract

We present detailed observations of the bright short-hard gamma-ray burst GRB 090510 made with the Gamma-ray Burst Monitor (GBM) and Large Area Telescope (LAT) on board the Fermi observatory. GRB 090510 is the first burst detected by the LAT that shows strong evidence for a deviation from a Band spectral fitting function during the prompt emission phase. The time-integrated spectrum is fit by the sum of a Band function with E _peak = 3.9 ± 0.3MeV, which is the highest yet measured, and a hard power-law component with photon index -1.62 ± 0.03 that dominates the emission below ≈ 20keV and above ≈ 100MeV. The onset of the high-energy spectral component appears to be delayed by ≈ 0.1s with respect to the onset of a component well fit with a single Band function. A faint GBM pulse and a LAT photon are detected 0.5s before the main pulse. During the prompt phase, the LAT detected a photon with energy 30.5^+5.8 _-2.6GeV, the highest ever measured from a short GRB. Observation of this photon sets a minimum bulk outflow Lorentz factor, Γ≳1200, using simple γγ opacity arguments for this GRB at redshift z = 0.903 and a variability timescale on the order of tens of ms for the ≈ 100keV-few MeV flux. Stricter high confidence estimates imply Γ ≳ 1000 and still require that the outflows powering short GRBs are at least as highly relativistic as those of long-duration GRBs. Implications of the temporal behavior and power-law shape of the additional component on synchrotron/synchrotron self-Compton, external-shock synchrotron, and hadronic models are considered.

Original language	English
Pages (from-to)	1178-1190
Number of pages	13
Journal	Astrophysical Journal
Volume	716
Issue number	2
DOIs	https://doi.org/10.1088/0004-637X/716/2/1178
State	Published - 2010
Externally published	Yes

Keywords

Gamma-ray burst: individual (GRB 090510)
Radiation mechanisms: non-thermal

Access to Document

10.1088/0004-637X/716/2/1178

Cite this

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., ... Ziegler, M. (2010). Fermi observations of GRB 090510: A short-hard gamma-ray burst with an additional, hard power-law component from 10 keV to GeV energies. Astrophysical Journal, 716(2), 1178-1190. https://doi.org/10.1088/0004-637X/716/2/1178

@article{a8c59b90e4f04d3ab66a21845b069ab7,

title = "Fermi observations of GRB 090510: A short-hard gamma-ray burst with an additional, hard power-law component from 10 keV to GeV energies",

abstract = "We present detailed observations of the bright short-hard gamma-ray burst GRB 090510 made with the Gamma-ray Burst Monitor (GBM) and Large Area Telescope (LAT) on board the Fermi observatory. GRB 090510 is the first burst detected by the LAT that shows strong evidence for a deviation from a Band spectral fitting function during the prompt emission phase. The time-integrated spectrum is fit by the sum of a Band function with E peak = 3.9 ± 0.3MeV, which is the highest yet measured, and a hard power-law component with photon index -1.62 ± 0.03 that dominates the emission below ≈ 20keV and above ≈ 100MeV. The onset of the high-energy spectral component appears to be delayed by ≈ 0.1s with respect to the onset of a component well fit with a single Band function. A faint GBM pulse and a LAT photon are detected 0.5s before the main pulse. During the prompt phase, the LAT detected a photon with energy 30.5+5.8 -2.6GeV, the highest ever measured from a short GRB. Observation of this photon sets a minimum bulk outflow Lorentz factor, Γ≳1200, using simple γγ opacity arguments for this GRB at redshift z = 0.903 and a variability timescale on the order of tens of ms for the ≈ 100keV-few MeV flux. Stricter high confidence estimates imply Γ ≳ 1000 and still require that the outflows powering short GRBs are at least as highly relativistic as those of long-duration GRBs. Implications of the temporal behavior and power-law shape of the additional component on synchrotron/synchrotron self-Compton, external-shock synchrotron, and hadronic models are considered.",

keywords = "Gamma-ray burst: individual (GRB 090510), Radiation mechanisms: non-thermal",

author = "M. Ackermann and K. Asano and Atwood, {W. B.} and M. Axelsson and L. Baldini and J. Ballet and G. Barbiellini and Baring, {M. G.} and D. Bastieri and K. Bechtol and R. Bellazzini and B. Berenji and Bhat, {P. N.} and E. Bissaldi and Blandford, {R. D.} and Bloom, {E. D.} and E. Bonamente and Borgland, {A. W.} and A. Bouvier and J. Bregeon and A. Brez and Briggs, {M. S.} and M. Brigida and P. Bruel and S. Buson and Caliandro, {G. A.} and Cameron, {R. A.} and Caraveo, {P. A.} and S. Carrigan and Casandjian, {J. M.} and C. Cecchi and {\"O} {\c C}elik and E. Charles and J. Chiang and S. Ciprini and R. Claus and J. Cohen-Tanugi and V. Connaughton and J. Conrad and Dermer, {C. D.} and {De Palma}, F. and Dingus, {B. L.} and {Do Couto E Silva}, E. and Drell, {P. S.} and R. Dubois and D. Dumora and C. Farnier and C. Favuzzi and Fegan, {S. J.} and J. Finke and Focke, {W. B.} and M. Frailis and Y. Fukazawa and P. Fusco and F. Gargano and D. Gasparrini and N. Gehrels and S. Germani and N. Giglietto and F. Giordano and T. Glanzman and G. Godfrey and J. Granot and Grenier, {I. A.} and Grondin, {M. H.} and Grove, {J. E.} and S. Guiriec and D. Hadasch and Harding, {A. K.} and E. Hays and D. Horan and Hughes, {R. E.} and G. J{\'o}hannesson and Johnson, {W. N.} and T. Kamae and H. Katagiri and J. Kataoka and N. Kawai and Kippen, {R. M.} and J. Kn{\"o}dlseder and D. Kocevski and C. Kouveliotou and M. Kuss and J. Lande and L. Latronico and M. Lemoine-Goumard and {Llena Garde}, M. and F. Longo and F. Loparco and B. Lott and Lovellette, {M. N.} and P. Lubrano and A. Makeev and Mazziotta, {M. N.} and McEnery, {J. E.} and S. McGlynn and C. Meegan and P. M{\'e}szros and Michelson, {P. F.} and W. Mitthumsiri and T. Mizuno and Moiseev, {A. A.} and C. Monte and Monzani, {M. E.} and E. Moretti and A. Morselli and Moskalenko, {I. V.} and S. Murgia and H. Nakajima and T. Nakamori and Nolan, {P. L.} and Norris, {J. P.} and E. Nuss and M. Ohno and T. Ohsugi and N. Omodei and E. Orlando and Ormes, {J. F.} and M. Ozaki and Paciesas, {W. S.} and D. Paneque and Panetta, {J. H.} and D. Parent and V. Pelassa and M. Pepe and M. Pesce-Rollins and F. Piron and R. Preece and S. Rain{\`o} and R. Rando and M. Razzano and S. Razzaque and A. Reimer and S. Ritz and Rodriguez, {A. Y.} and M. Roth and F. Ryde and Sadrozinski, {H. F.W.} and A. Sander and Scargle, {J. D.} and Schalk, {T. L.} and C. Sgr{\`o} and Siskind, {E. J.} and Smith, {P. D.} and G. Spandre and P. Spinelli and M. Stamatikos and Stecker, {F. W.} and Strickman, {M. S.} and Suson, {D. J.} and H. Tajima and H. Takahashi and T. Takahashi and T. Tanaka and Thayer, {J. B.} and Thayer, {J. G.} and Thompson, {D. J.} and L. Tibaldo and K. Toma and Torres, {D. F.} and G. Tosti and A. Tramacere and Y. Uchiyama and T. Uehara and Usher, {T. L.} and {Van Der Horst}, {A. J.} and V. Vasileiou and N. Vilchez and V. Vitale and {Von Kienlin}, A. and Waite, {A. P.} and P. Wang and C. Wilson-Hodge and Winer, {B. L.} and Wu, {X. F.} and R. Yamazaki and Z. Yang and T. Ylinen and M. Ziegler",

year = "2010",

doi = "10.1088/0004-637X/716/2/1178",

language = "אנגלית",

volume = "716",

pages = "1178--1190",

journal = "Astrophysical Journal",

issn = "0004-637X",

publisher = "IOP Publishing Ltd.",

number = "2",

}

Ackermann, M, Asano, K, Atwood, WB, Axelsson, M, Baldini, L, Ballet, J, Barbiellini, G, Baring, MG, Bastieri, D, Bechtol, K, Bellazzini, R, Berenji, B, Bhat, PN, Bissaldi, E, Blandford, RD, Bloom, ED, Bonamente, E, Borgland, AW, Bouvier, A, Bregeon, J, Brez, A, Briggs, MS, Brigida, M, Bruel, P, Buson, S, Caliandro, GA, Cameron, RA, Caraveo, PA, Carrigan, S, Casandjian, JM, Cecchi, C, Çelik, Ö, Charles, E, Chiang, J, Ciprini, S, Claus, R, Cohen-Tanugi, J, Connaughton, V, Conrad, J, Dermer, CD, De Palma, F, Dingus, BL, Do Couto E Silva, E, Drell, PS, Dubois, R, Dumora, D, Farnier, C, Favuzzi, C, Fegan, SJ, Finke, J, Focke, WB, Frailis, M, Fukazawa, Y, Fusco, P, Gargano, F, Gasparrini, D, Gehrels, N, Germani, S, Giglietto, N, Giordano, F, Glanzman, T, Godfrey, G, Granot, J, Grenier, IA, Grondin, MH, Grove, JE, Guiriec, S, Hadasch, D, Harding, AK, Hays, E, Horan, D, Hughes, RE, Jóhannesson, G, Johnson, WN, Kamae, T, Katagiri, H, Kataoka, J, Kawai, N, Kippen, RM, Knödlseder, J, Kocevski, D, Kouveliotou, C, Kuss, M, Lande, J, Latronico, L, Lemoine-Goumard, M, Llena Garde, M, Longo, F, Loparco, F, Lott, B, Lovellette, MN, Lubrano, P, Makeev, A, Mazziotta, MN, McEnery, JE, McGlynn, S, Meegan, C, Mészros, P, Michelson, PF, Mitthumsiri, W, Mizuno, T, Moiseev, AA, Monte, C, Monzani, ME, Moretti, E, Morselli, A, Moskalenko, IV, Murgia, S, Nakajima, H, Nakamori, T, Nolan, PL, Norris, JP, Nuss, E, Ohno, M, Ohsugi, T, Omodei, N, Orlando, E, Ormes, JF, Ozaki, M, Paciesas, WS, Paneque, D, Panetta, JH, Parent, D, Pelassa, V, Pepe, M, Pesce-Rollins, M, Piron, F, Preece, R, Rainò, S, Rando, R, Razzano, M, Razzaque, S, Reimer, A, Ritz, S, Rodriguez, AY, Roth, M, Ryde, F, Sadrozinski, HFW, Sander, A, Scargle, JD, Schalk, TL, Sgrò, C, Siskind, EJ, Smith, PD, Spandre, G, Spinelli, P, Stamatikos, M, Stecker, FW, Strickman, MS, Suson, DJ, Tajima, H, Takahashi, H, Takahashi, T, Tanaka, T, Thayer, JB, Thayer, JG, Thompson, DJ, Tibaldo, L, Toma, K, Torres, DF, Tosti, G, Tramacere, A, Uchiyama, Y, Uehara, T, Usher, TL, Van Der Horst, AJ, Vasileiou, V, Vilchez, N, Vitale, V, Von Kienlin, A, Waite, AP, Wang, P, Wilson-Hodge, C, Winer, BL, Wu, XF, Yamazaki, R, Yang, Z, Ylinen, T & Ziegler, M 2010, 'Fermi observations of GRB 090510: A short-hard gamma-ray burst with an additional, hard power-law component from 10 keV to GeV energies', Astrophysical Journal, vol. 716, no. 2, pp. 1178-1190. https://doi.org/10.1088/0004-637X/716/2/1178

TY - JOUR

T1 - Fermi observations of GRB 090510

T2 - A short-hard gamma-ray burst with an additional, hard power-law component from 10 keV to GeV energies

AU - Ackermann, M.

AU - Asano, K.

AU - Atwood, W. B.

AU - Axelsson, M.

AU - Baldini, L.

AU - Ballet, J.

AU - Barbiellini, G.

AU - Baring, M. G.

AU - Bastieri, D.

AU - Bechtol, K.

AU - Bellazzini, R.

AU - Berenji, B.

AU - Bhat, P. N.

AU - Bissaldi, E.

AU - Blandford, R. D.

AU - Bloom, E. D.

AU - Bonamente, E.

AU - Borgland, A. W.

AU - Bouvier, A.

AU - Bregeon, J.

AU - Brez, A.

AU - Briggs, M. S.

AU - Brigida, M.

AU - Bruel, P.

AU - Buson, S.

AU - Caliandro, G. A.

AU - Cameron, R. A.

AU - Caraveo, P. A.

AU - Carrigan, S.

AU - Casandjian, J. M.

AU - Cecchi, C.

AU - Çelik, Ö

AU - Charles, E.

AU - Chiang, J.

AU - Ciprini, S.

AU - Claus, R.

AU - Cohen-Tanugi, J.

AU - Connaughton, V.

AU - Conrad, J.

AU - Dermer, C. D.

AU - De Palma, F.

AU - Dingus, B. L.

AU - Do Couto E Silva, E.

AU - Drell, P. S.

AU - Dubois, R.

AU - Dumora, D.

AU - Farnier, C.

AU - Favuzzi, C.

AU - Fegan, S. J.

AU - Finke, J.

AU - Focke, W. B.

AU - Frailis, M.

AU - Fukazawa, Y.

AU - Fusco, P.

AU - Gargano, F.

AU - Gasparrini, D.

AU - Gehrels, N.

AU - Germani, S.

AU - Giglietto, N.

AU - Giordano, F.

AU - Glanzman, T.

AU - Godfrey, G.

AU - Granot, J.

AU - Grenier, I. A.

AU - Grondin, M. H.

AU - Grove, J. E.

AU - Guiriec, S.

AU - Hadasch, D.

AU - Harding, A. K.

AU - Hays, E.

AU - Horan, D.

AU - Hughes, R. E.

AU - Jóhannesson, G.

AU - Johnson, W. N.

AU - Kamae, T.

AU - Katagiri, H.

AU - Kataoka, J.

AU - Kawai, N.

AU - Kippen, R. M.

AU - Knödlseder, J.

AU - Kocevski, D.

AU - Kouveliotou, C.

AU - Kuss, M.

AU - Lande, J.

AU - Latronico, L.

AU - Lemoine-Goumard, M.

AU - Llena Garde, M.

AU - Longo, F.

AU - Loparco, F.

AU - Lott, B.

AU - Lovellette, M. N.

AU - Lubrano, P.

AU - Makeev, A.

AU - Mazziotta, M. N.

AU - McEnery, J. E.

AU - McGlynn, S.

AU - Meegan, C.

AU - Mészros, P.

AU - Michelson, P. F.

AU - Mitthumsiri, W.

AU - Mizuno, T.

AU - Moiseev, A. A.

AU - Monte, C.

AU - Monzani, M. E.

AU - Moretti, E.

AU - Morselli, A.

AU - Moskalenko, I. V.

AU - Murgia, S.

AU - Nakajima, H.

AU - Nakamori, T.

AU - Nolan, P. L.

AU - Norris, J. P.

AU - Nuss, E.

AU - Ohno, M.

AU - Ohsugi, T.

AU - Omodei, N.

AU - Orlando, E.

AU - Ormes, J. F.

AU - Ozaki, M.

AU - Paciesas, W. S.

AU - Paneque, D.

AU - Panetta, J. H.

AU - Parent, D.

AU - Pelassa, V.

AU - Pepe, M.

AU - Pesce-Rollins, M.

AU - Piron, F.

AU - Preece, R.

AU - Rainò, S.

AU - Rando, R.

AU - Razzano, M.

AU - Razzaque, S.

AU - Reimer, A.

AU - Ritz, S.

AU - Rodriguez, A. Y.

AU - Roth, M.

AU - Ryde, F.

AU - Sadrozinski, H. F.W.

AU - Sander, A.

AU - Scargle, J. D.

AU - Schalk, T. L.

AU - Sgrò, C.

AU - Siskind, E. J.

AU - Smith, P. D.

AU - Spandre, G.

AU - Spinelli, P.

AU - Stamatikos, M.

AU - Stecker, F. W.

AU - Strickman, M. S.

AU - Suson, D. J.

AU - Tajima, H.

AU - Takahashi, H.

AU - Takahashi, T.

AU - Tanaka, T.

AU - Thayer, J. B.

AU - Thayer, J. G.

AU - Thompson, D. J.

AU - Tibaldo, L.

AU - Toma, K.

AU - Torres, D. F.

AU - Tosti, G.

AU - Tramacere, A.

AU - Uchiyama, Y.

AU - Uehara, T.

AU - Usher, T. L.

AU - Van Der Horst, A. J.

AU - Vasileiou, V.

AU - Vilchez, N.

AU - Vitale, V.

AU - Von Kienlin, A.

AU - Waite, A. P.

AU - Wang, P.

AU - Wilson-Hodge, C.

AU - Winer, B. L.

AU - Wu, X. F.

AU - Yamazaki, R.

AU - Yang, Z.

AU - Ylinen, T.

AU - Ziegler, M.

PY - 2010

Y1 - 2010

N2 - We present detailed observations of the bright short-hard gamma-ray burst GRB 090510 made with the Gamma-ray Burst Monitor (GBM) and Large Area Telescope (LAT) on board the Fermi observatory. GRB 090510 is the first burst detected by the LAT that shows strong evidence for a deviation from a Band spectral fitting function during the prompt emission phase. The time-integrated spectrum is fit by the sum of a Band function with E peak = 3.9 ± 0.3MeV, which is the highest yet measured, and a hard power-law component with photon index -1.62 ± 0.03 that dominates the emission below ≈ 20keV and above ≈ 100MeV. The onset of the high-energy spectral component appears to be delayed by ≈ 0.1s with respect to the onset of a component well fit with a single Band function. A faint GBM pulse and a LAT photon are detected 0.5s before the main pulse. During the prompt phase, the LAT detected a photon with energy 30.5+5.8 -2.6GeV, the highest ever measured from a short GRB. Observation of this photon sets a minimum bulk outflow Lorentz factor, Γ≳1200, using simple γγ opacity arguments for this GRB at redshift z = 0.903 and a variability timescale on the order of tens of ms for the ≈ 100keV-few MeV flux. Stricter high confidence estimates imply Γ ≳ 1000 and still require that the outflows powering short GRBs are at least as highly relativistic as those of long-duration GRBs. Implications of the temporal behavior and power-law shape of the additional component on synchrotron/synchrotron self-Compton, external-shock synchrotron, and hadronic models are considered.

AB - We present detailed observations of the bright short-hard gamma-ray burst GRB 090510 made with the Gamma-ray Burst Monitor (GBM) and Large Area Telescope (LAT) on board the Fermi observatory. GRB 090510 is the first burst detected by the LAT that shows strong evidence for a deviation from a Band spectral fitting function during the prompt emission phase. The time-integrated spectrum is fit by the sum of a Band function with E peak = 3.9 ± 0.3MeV, which is the highest yet measured, and a hard power-law component with photon index -1.62 ± 0.03 that dominates the emission below ≈ 20keV and above ≈ 100MeV. The onset of the high-energy spectral component appears to be delayed by ≈ 0.1s with respect to the onset of a component well fit with a single Band function. A faint GBM pulse and a LAT photon are detected 0.5s before the main pulse. During the prompt phase, the LAT detected a photon with energy 30.5+5.8 -2.6GeV, the highest ever measured from a short GRB. Observation of this photon sets a minimum bulk outflow Lorentz factor, Γ≳1200, using simple γγ opacity arguments for this GRB at redshift z = 0.903 and a variability timescale on the order of tens of ms for the ≈ 100keV-few MeV flux. Stricter high confidence estimates imply Γ ≳ 1000 and still require that the outflows powering short GRBs are at least as highly relativistic as those of long-duration GRBs. Implications of the temporal behavior and power-law shape of the additional component on synchrotron/synchrotron self-Compton, external-shock synchrotron, and hadronic models are considered.

KW - Gamma-ray burst: individual (GRB 090510)

KW - Radiation mechanisms: non-thermal

UR - http://www.scopus.com/inward/record.url?scp=77953213402&partnerID=8YFLogxK

U2 - 10.1088/0004-637X/716/2/1178

DO - 10.1088/0004-637X/716/2/1178

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AN - SCOPUS:77953213402

SN - 0004-637X

VL - 716

SP - 1178

EP - 1190

JO - Astrophysical Journal

JF - Astrophysical Journal

IS - 2

ER -

Fermi observations of GRB 090510: A short-hard gamma-ray burst with an additional, hard power-law component from 10 keV to GeV energies

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