Cosmic ray electrons and the diffuse gamma-ray spectrum

被引:47
作者
Porter, TA
Protheroe, RJ
机构
[1] Dept. of Phys. and Math. Physics, University of Adelaide, Adelaide
关键词
D O I
10.1088/0954-3899/23/11/022
中图分类号
O57 [原子核物理学、高能物理学];
学科分类号
070202 ;
摘要
The bulk of the diffuse galactic gamma-ray emission above a few tens of GeV has been conventionally ascribed to the decay of neutral pions produced in cosmic-ray interactions with interstellar matter. Cosmic-ray electrons may, however, make a significant contribution to the gamma-ray spectrum at high energies, and even dominate at TeV-PeV energies depending on their injection spectral index and acceleration cut-off energy. If the injection spectrum is flat, the highest energy electrons will also contribute a diffuse hard x-ray/soft gamma-ray flux via synchrotron emission, and this may offer an explanation for the OSSE observation of a steep spectrum below a few MeV from the inner Galaxy. We perform a propagation calculation for cosmic-ray electrons, and use the resulting interstellar electron spectrum to obtain the gamma-ray spectrum due to inverse Compton, synchrotron and bremsstrahlung interactions consistently from MeV to PeV energies. We compare our results with available observations from satellite-borne telescopes, optical Cerenkov telescopes and air shower arrays and place constraints on the injection spectrum of cosmic-ray electrons. With future observations at TeV-PeV energies it should be possible to determine the average interstellar spectrum of cosmic-ray electrons, and hence estimate their spectrum on acceleration.
引用
收藏
页码:1765 / 1784
页数:20
相关论文
共 70 条
[1]  
AHARONIAN FA, 1995, ASTRON ASTROPHYS, V294, pL41
[2]   ELECTRONS AND POSITRONS IN THE GALACTIC COSMIC-RAYS [J].
ATOYAN, AM ;
AHARONIAN, FA ;
VOLK, HJ .
PHYSICAL REVIEW D, 1995, 52 (06) :3265-3275
[3]   Diffuse radiation from cosmic ray interactions in the galaxy [J].
Berezinsky, V. S. ;
Gaisser, T. K. ;
Halzen, F. ;
Stanev, Todor .
ASTROPARTICLE PHYSICS, 1993, 1 (03) :281-287
[4]   DIFFUSE GAMMA-RAY EMISSION IN THE GALACTIC PLANE FROM COSMIC-RAY, MATTER, AND PHOTON INTERACTIONS [J].
BERTSCH, DL ;
DAME, TM ;
FICHTEL, CE ;
HUNTER, SD ;
SREEKUMAR, P ;
STACY, JG ;
THADDEUS, P .
ASTROPHYSICAL JOURNAL, 1993, 416 (02) :587-600
[5]  
BLOEMEN JBG, 1985, THESIS U LEIDEN
[6]  
Bloom ED, 1996, SPACE SCI REV, V75, P109, DOI 10.1007/BF00195029
[7]   BREMSSTRAHLUNG, SYNCHROTRON RADIATION, AND COMPTON SCATTERING OF HIGH-ENERGY ELECTRONS TRAVERSING DILUTE GASES [J].
BLUMENTHAL, GR ;
GOULD, RJ .
REVIEWS OF MODERN PHYSICS, 1970, 42 (02) :237-+
[8]  
BORIONE A, 1997, UNPUB ASTROPHYS J
[9]   A TECHNIQUE FOR SEPARATING THE GALACTIC THERMAL RADIO-EMISSION FROM THE NON-THERMAL COMPONENT BY MEANS OF THE ASSOCIATED INFRARED-EMISSION [J].
BROADBENT, A ;
HASLAM, CGT ;
OSBORNE, JL .
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 1989, 237 (02) :381-&
[10]  
Broadbent A., 1990, International Cosmic Ray Conference, V3, P229