The early X-ray emission from GRBs

被引:388
作者
O'Brien, P. T.
Willingale, R.
Osborne, J.
Goad, M. R.
Page, K. L. [1 ]
Vaughan, S.
Rol, E.
Beardmore, A.
Godet, O.
Hurkett, C. P.
Wells, A.
Zhang, B.
Kobayashi, S.
Burrows, D. N.
Nousek, J. A.
Kennea, J. A.
Falcone, A.
Grupe, D.
Gehrels, N.
Barthelmy, S.
Cannizzo, J.
Cummings, J.
Hill, J. E.
Krimm, H.
Chincarini, G.
Tagliaferri, G.
Campana, S.
Moretti, A.
Giommi, P.
Perri, M.
Mangano, V.
LaParola, V.
机构
[1] Univ Leicester, Dept Phys & Astron, Leicester LE1 7RH, Leics, England
[2] Univ Nevada, Dept Phys, Las Vegas, NV 89154 USA
[3] Liverpool John Moores Univ, Astrophys Res Inst, Birkenhead CH41 1LD, Merseyside, England
[4] Penn State Univ, Dept Astron & Astrophys, University Pk, PA 16802 USA
[5] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA
[6] Univ Maryland Baltimore Cty, Joint Ctr Astrophys, Baltimore, MD 21250 USA
[7] CNR, Washington, DC 20418 USA
[8] Univ Space Res Assoc, Columbia, MD 21044 USA
[9] Osserv Astron Brera, INAF, I-23807 Merate, LC, Italy
[10] Univ Milan, Dipartimento Fis, I-20126 Milan, Italy
[11] ASI Sci Data Ctr, I-00044 Frascati, Italy
[12] INAF, Ist Astrofis Spaziale & Fis Cosm, Sez Palermo, I-90146 Palermo, Italy
关键词
accretion; accretion disks; black hole physics; gamma rays : bursts;
D O I
10.1086/505457
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
We present observations of the early X-ray emission for a sample of 40 gamma-ray bursts (GRBs) obtained using the Swift satellite, for which the narrow-field instruments were pointed at the burst within 10 minutes of the trigger. Using data from the Burst Alert Telescope and the X-Ray Telescope, we show that the X-ray light curve can be well described by an exponential that relaxes into a power law, often with flares superimposed. The transition time between the exponential and the power law provides a physically defined timescale for the burst duration. In most bursts, the power law breaks to a shallower decay within the first hour, and a late emission "hump'' is observed, which can last for many hours. In other GRBs the hump is weak or absent. The observed variety in the shape of the early X-ray light curve can be explained as a combination of three components: prompt emission from the central engine, afterglow, and the late hump. In this scenario, afterglow emission begins during or soon after the burst, and the observed shape of the X-ray light curve depends on the relative strengths of the emission due to the central engine and that of the afterglow. There is a strong correlation such that those GRBs with stronger afterglow components have brighter early optical emission. The late emission hump can have a total fluence equivalent to that of the prompt phase. GRBs with the strongest late humps have weak or no X-ray flares.
引用
收藏
页码:1213 / 1237
页数:25
相关论文
共 72 条
[1]   SOLAR-SYSTEM ABUNDANCES OF THE ELEMENTS [J].
ANDERS, E ;
EBIHARA, M .
GEOCHIMICA ET COSMOCHIMICA ACTA, 1982, 46 (11) :2363-2380
[2]  
Arnaud KA, 1996, ASTR SOC P, V101, P17
[3]   Postlaunch analysis of Swift's gamma-ray burst detection sensitivity [J].
Band, David L. .
ASTROPHYSICAL JOURNAL, 2006, 644 (01) :378-384
[4]   The burst alert telescope (BAT) on the Swift MIDEX mission [J].
Barthelmy, SD ;
Barbier, LM ;
Cummings, JR ;
Fenimore, EE ;
Gehrels, N ;
Hullinger, D ;
Krimm, HA ;
Markwardt, CB ;
Palmer, DM ;
Parsons, A ;
Sato, G ;
Suzuki, M ;
Takahashi, T ;
Tashiro, M ;
Tueller, J .
SPACE SCIENCE REVIEWS, 2005, 120 (3-4) :143-164
[5]   An origin for short γ-ray bursts unassociated with current star formation [J].
Barthelmy, SD ;
Chincarini, G ;
Burrows, DN ;
Gehrels, N ;
Covino, S ;
Moretti, A ;
Romano, P ;
O'Brien, PT ;
Sarazin, CL ;
Kouveliotou, C ;
Goad, M ;
Vaughan, S ;
Tagliaferri, G ;
Zhang, B ;
Antonelli, LA ;
Campana, S ;
Cummings, JR ;
D'Avanzo, P ;
Davies, MB ;
Giommi, P ;
Grupe, D ;
Kaneko, Y ;
Kennea, JA ;
King, A ;
Kobayashi, S ;
Melandri, A ;
Meszaros, P ;
Nousek, JA ;
Patel, S ;
Sakamoto, T ;
Wijers, RAMJ .
NATURE, 2005, 438 (7070) :994-996
[6]  
BEARDMORE AP, 2006, UNPUB MNRAS
[7]   Afterglows, redshifts, and properties of Swift gamma-ray bursts [J].
Berger, E ;
Kulkarni, SR ;
Fox, DB ;
Soderberg, AM ;
Harrison, FA ;
Nakar, E ;
Kelson, DD ;
Gladders, MD ;
Mulchaey, JS ;
Oemler, A ;
Dressler, A ;
Cenko, SB ;
Price, PA ;
Schmidt, BP ;
Frail, DA ;
Morrell, N ;
Gonzalez, S ;
Krzeminski, W ;
Sari, R ;
Gal-Yam, A ;
Moon, DS ;
Penprase, BE ;
Jayawardhana, R ;
Scholz, A ;
Rich, J ;
Peterson, BA ;
Anderson, G ;
McNaught, R ;
Minezaki, T ;
Yoshii, Y ;
Cowie, LL ;
Pimbblet, K .
ASTROPHYSICAL JOURNAL, 2005, 634 (01) :501-508
[8]  
BERGER E, 2005, 3088 GCN
[9]   Closing in on a short-hard burst progenitor: Constraints from early-time optical imaging and spectroscopy of a possible host galaxy of GRB 050509b [J].
Bloom, JS ;
Prochaska, JX ;
Pooley, D ;
Blake, CH ;
Foley, RJ ;
Jha, S ;
Ramirez-Ruiz, E ;
Granot, J ;
Filippenko, AV ;
Sigurdsson, S ;
Barth, AJ ;
Chen, HW ;
Cooper, MC ;
Falco, EE ;
Gal, RR ;
Gerke, BF ;
Gladders, MD ;
Greene, JE ;
Hennanwi, J ;
Ho, LC ;
Hurley, K ;
Koester, BP ;
Li, W ;
Lubin, L ;
Newman, J ;
Perley, DA ;
Squires, GK ;
Wood-Vasey, WM .
ASTROPHYSICAL JOURNAL, 2006, 638 (01) :354-368
[10]  
BLOOM JS, 2005, 3758 GCN