The contribution of Fermi gamma-ray pulsars to the local flux of cosmic-ray electrons and positrons

被引:19
|
作者
Gendelev, Leo [1 ]
Profumo, Stefano [1 ,2 ]
Dormody, Michael [1 ,2 ]
机构
[1] Univ Calif Santa Cruz, Dept Phys, Santa Cruz, CA 95064 USA
[2] Univ Calif Santa Cruz, Santa Cruz Inst Particle Phys, Santa Cruz, CA 95064 USA
基金
美国国家科学基金会;
关键词
cosmic ray theory; gamma ray theory; radio pulsars; OUTER MAGNETOSPHERE; AREA TELESCOPE; PAIR CREATION; POLAR GAPS; SLOT GAPS; RADIATION; CASCADES; SPECTRUM; GEMINGA;
D O I
10.1088/1475-7516/2010/02/016
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
We analyze the contribution of gamma-ray pulsars from the first Fermi-Large Area Telescope (LAT) catalogue to the local flux of cosmic-ray electrons and positrons (e(+)e(-)). We present new distance estimates for all Fermi gamma-ray pulsars, based on the measured gamma-ray flux and pulse shape. We then estimate the contribution of gamma-ray pulsars to the local e(+)e(-) flux, in the context of a simple model for the pulsar e(+)e(-) emission. We find that 10 of the Fermi pulsars potentially contribute significantly to the measured e(+)e(-) flux in the energy range between 100 GeV and 1 TeV. Of the 10 pulsars, 2 are old EGRET gamma-ray pulsars, 2 pulsars were discovered with radio ephemerides, and 6 were discovered with the Fermi pulsar blind-search campaign. We argue that known radio pulsars fall in regions of parameter space where the e(+)e(-) contribution is predicted to be typically much smaller than from those regions where Fermi-LAT pulsars exist. However, comparing the Fermi gamma-ray flux sensitivity to the regions of pulsar parameter space where a significant e(+)e(-) contribution is predicted, we find that a few known radio pulsars that have not yet been detected by Fermi can also significantly contribute to the local e(+)e(-) flux if (i) they are closer than 2 kpc, and if (ii) they have a characteristic age on the order of one mega-year.
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页数:21
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