A compact fireball model of gamma-ray bursts

被引:83
作者
Eichler, D [1 ]
Levinson, A
机构
[1] Ben Gurion Univ Negev, Dept Phys, IL-84105 Beer Sheva, Israel
[2] Tel Aviv Univ, IL-69978 Tel Aviv, Israel
关键词
BL Lacertae objects : general; gamma rays : bursts; radiation mechanisms : thermal;
D O I
10.1086/308245
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
It is proposed that the gamma-ray burst (GRB) photons near the peak of the spectrum at several hundred keV are produced on very compact scales, where photon production is limited by blackbody effects and/or the requirement of energetic quanta (E > 2m(e)c(2)) for efficient further production. The fast variation of order milliseconds in the time profile is then a natural expectation, given the other observed GRB parameters. Analytic calculations are presented to show that the escape of nonthermal, energetic gamma rays can emerge within 1 s of the thermal photons from a gammasphere of below 10(12) cm. The minimum asymptotic bulk Lorentz factor in this model is found to be of order several hundred if the photosphere is of order 3 x 10(11) cm and greater for larger or smaller photospheric radii. It is suggested that prompt ultra-high-energy gamma rays might provide a new constraint on the asymptotic Lorentz factor of the outflow.
引用
收藏
页码:146 / 150
页数:5
相关论文
共 19 条
[1]   BATSE OBSERVATIONS OF GAMMA-RAY BURST SPECTRA .1. SPECTRAL DIVERSITY [J].
BAND, D ;
MATTESON, J ;
FORD, L ;
SCHAEFER, B ;
PALMER, D ;
TEEGARDEN, B ;
CLINE, T ;
BRIGGS, M ;
PACIESAS, W ;
PENDLETON, G ;
FISHMAN, G ;
KOUVELIOTOU, C ;
MEEGAN, C ;
WILSON, R ;
LESTRADE, P .
ASTROPHYSICAL JOURNAL, 1993, 413 (01) :281-292
[2]   PAIR CASCADES IN EXTRAGALACTIC JETS .1. GAMMA-RAYS [J].
BLANDFORD, RD ;
LEVINSON, A .
ASTROPHYSICAL JOURNAL, 1995, 441 (01) :79-95
[3]   HYDROMAGNETIC FLOWS FROM ACCRETION DISKS AND THE PRODUCTION OF RADIO JETS [J].
BLANDFORD, RD ;
PAYNE, DG .
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 1982, 199 (03) :883-903
[4]  
CAVALLO G, 1978, MON NOT R ASTRON SOC, V183, P359, DOI 10.1093/mnras/183.3.359
[5]   The external shock model of gamma-ray bursts:: Three predictions and a paradox resolved [J].
Dermer, CD ;
Böttcher, M ;
Chiang, J .
ASTROPHYSICAL JOURNAL, 1999, 515 (02) :L49-L52
[6]   Shading and smothering of gamma-ray bursts [J].
Eichler, D ;
Levinson, A .
ASTROPHYSICAL JOURNAL, 1999, 521 (02) :L117-L120
[7]   PARTICLE-ACCELERATION IN HIGH-ENERGY GAMMA-RAY SOURCES [J].
EICHLER, D .
ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES, 1994, 90 (02) :877-881
[8]   ARE GAMMA-RAY BURSTS OPTICALLY THICK [J].
GOODMAN, J .
ASTROPHYSICAL JOURNAL, 1986, 308 (02) :L47-L50
[9]   THE X-RAY-EMISSION FROM GAMMA-RAY BURST SOURCES - CONSTRAINTS ON THEORETICAL-MODELS [J].
IMAMURA, JN ;
EPSTEIN, RI .
ASTROPHYSICAL JOURNAL, 1987, 313 (02) :711-717
[10]   BARYON PURITY IN COSMOLOGICAL GAMMA-RAY BURSTS AS A MANIFESTATION OF EVENT HORIZONS [J].
LEVINSON, A ;
EICHLER, D .
ASTROPHYSICAL JOURNAL, 1993, 418 (01) :386-390