X-ray observations of TeV blazars and multi-frequency analysis

被引:35
作者
Takahashi, T [1 ]
Madejski, G
Kubo, H
机构
[1] Inst Space & Astronaut Sci, Kanagawa 2298510, Japan
[2] NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA
[3] Tokyo Inst Technol, Dept Phys, Meguro Ku, Tokyo 1528551, Japan
关键词
galaxies : active; galaxies : jet; BL Lacertae objects : general; BL Lacertae objects : individual (Markarian 421); quasars : general; gamma-rays : theory;
D O I
10.1016/S0927-6505(99)00045-6
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
The nonthermal spectra of blazars, observed from radio to GeV/TeV gamma-rays, reveal two pronounced components, both produced by radiation by energetic particles. One peaks in the IR-to-soft X-ray band, radiating via the synchrotron process; the other, peaking in the high-energy gamma-rays, is produced by the Compton process. These spectra - and, in particular, the ASCA data - suggest that the origin of the seed photons for Comptonization is diverse. In the High-energy peaked BL Lac objects (HBLs), the dominant seed photons for Comptonization appear to be the synchrotron photons internal to the jet (SSC process). In the quasar-hosted blazars (QHBs), on the other hand, the X-ray band emission is still dominated by the SSC process, while the MeV to GeV range is produced by Comptonization of external photons such as the emission line light. In the context of this three-component model, we derive the magnetic field of 0.1-1 Gauss for all classes of blazars. Lorentz factors gamma(peak) of electrons radiating at each peak of the nu F(nu) spectra are estimated to be similar to 10(5) for HBLs; this is much higher than similar to 10(3) for QHBs. This difference is consistent with the fact that the four sources that are known to emit TeV gamma-rays (TeV blazars) are all classified as HBLs. Among the TeV blazars, Mkn 421 is one of the brightest and most variable emitters from ultraviolet (eV) to hard gamma-ray (TeV) energies, and its correlated inter-band variability suggests that both keV and TeV spectral regimes are produced by the same, most energetic end of the electron population radiating via the synchrotron process in the keV, and the SSC process in TeV band. The multi-frequency observations including TeV energy band provide the best opportunity to understand high-energy emission from blazar jets. In this paper, we discuss results of multi-frequency analysis and review the results of intensive campaigns for Mkn 421 from 1994 to 1998. (C) 1999 Elsevier Science B.V. All rights reserved.
引用
收藏
页码:177 / 187
页数:11
相关论文
共 49 条
[1]   PAIR CASCADES IN EXTRAGALACTIC JETS .1. GAMMA-RAYS [J].
BLANDFORD, RD ;
LEVINSON, A .
ASTROPHYSICAL JOURNAL, 1995, 441 (01) :79-95
[2]   RELATIVISTIC JETS AS COMPACT RADIO-SOURCES [J].
BLANDFORD, RD ;
KONIGL, A .
ASTROPHYSICAL JOURNAL, 1979, 232 (01) :34-48
[3]  
BRINKMANN W, 1994, ASTRON ASTROPHYS, V288, P433
[4]   Gamma-ray variability of the BL Lacertae object markarian 421 [J].
Buckley, JH ;
Akerlof, CW ;
Biller, S ;
CarterLewis, DA ;
Catanese, M ;
Cawley, MF ;
Connaughton, V ;
Fegan, DJ ;
Finley, JP ;
Gaidos, J ;
Hillas, AM ;
Kartje, JF ;
Konigl, A ;
Krennrich, F ;
Lamb, RC ;
Lessard, R ;
Macomb, DJ ;
Mattox, JR ;
McEnery, JE ;
Mohanty, G ;
Quinn, J ;
Rodgers, AJ ;
Rose, HJ ;
Schubnel, MS ;
Sembroski, GL ;
Smith, PS ;
Weekes, TC ;
Wilson, C ;
Zweerink, J .
ASTROPHYSICAL JOURNAL, 1996, 472 (01) :L9-L12
[5]   Discovery of gamma-ray emission above 350 GeV from the BL Lacertae object 1ES 2344+514 [J].
Catanese, M ;
Akerlof, CW ;
Badran, HM ;
Biller, SD ;
Bond, IH ;
Boyle, PJ ;
Bradbury, SM ;
Buckley, JH ;
Burdett, AM ;
Gordo, JB ;
Carter-Lewis, DA ;
Cawley, MF ;
Connaughton, V ;
Fegan, DJ ;
Finley, JP ;
Gaidos, JA ;
Hall, T ;
Hillas, AM ;
Krennrich, F ;
Lamb, RC ;
Lessard, RW ;
Masterson, C ;
McEnery, JE ;
Mohanty, G ;
Quinn, J ;
Rodgers, AJ ;
Rose, HJ ;
Samuelson, FW ;
Schubnell, MS ;
Sembroski, GH ;
Srinivasan, R ;
Weekes, TC ;
Wilson, CW ;
Zweerink, J .
ASTROPHYSICAL JOURNAL, 1998, 501 (02) :616-623
[6]   Multiwavelength observations of a flare from Markarian 501 [J].
Catanese, M ;
Bradbury, SM ;
Breslin, AC ;
Buckley, JH ;
CarterLewis, DA ;
Cawley, MF ;
Dermer, CD ;
Fegan, DJ ;
Finley, JP ;
Gaidos, JA ;
Hillas, AM ;
Johnson, WN ;
Krennrich, F ;
Lamb, RC ;
Lessard, RW ;
Macomb, DJ ;
McEnery, JE ;
Moriarty, P ;
Quinn, J ;
Rodgers, AJ ;
Rose, HJ ;
Samuelson, FW ;
Sembroski, GH ;
Srinivasan, R ;
Weekes, TC ;
Zweerink, J .
ASTROPHYSICAL JOURNAL, 1997, 487 (02) :L143-L146
[7]  
CHADWICK PM, 1998, IN PRESS APJ
[8]   On the soft X-ray spectra of gamma-loud blazars [J].
Comastri, A ;
Fossati, G ;
Ghisellini, G ;
Molendi, S .
ASTROPHYSICAL JOURNAL, 1997, 480 (02) :534-546
[9]  
DERMER CD, 1992, ASTRON ASTROPHYS, V256, pL27
[10]   On spectral and temporal variability in blazars and gamma-ray bursts [J].
Dermer, CD .
ASTROPHYSICAL JOURNAL, 1998, 501 (02) :L157-L161