
Contribution to diffuse gamma‐rays in the Galactic Centre region from unresolved millisecond pulsars
Author(s) -
Wang W.,
Jiang Z. J.,
Cheng K. S.
Publication year - 2005
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1111/j.1365-2966.2005.08816.x
Subject(s) - physics , millisecond pulsar , astrophysics , pulsar , egret , gamma ray , astronomy , galactic center , population , galactic plane , synchrotron radiation , galaxy , nuclear physics , demography , sociology
Diffuse gamma‐rays in the Galactic Centre region have been studied. We propose that there exists a population of millisecond pulsars in the Galactic Centre, which emit GeV gamma‐rays through synchrotron‐curvature radiation as predicted by outer gap models. These GeV gamma‐rays from unresolved millisecond pulsars probably contribute to the diffuse gamma‐ray spectrum detected by EGRET which displays a break at a few GeV. We have used a Monte Carlo method to obtain simulated samples of millisecond pulsars in the Galactic Centre region covered by EGRET (∼ 15) according to the different period and magnetic field distributions from observed millisecond pulsars in the Galactic field and globular clusters, and superposed their synchrotron‐curvature spectra to derive the total GeV flux. Our simulated results suggest that there probably exist about 6000 unresolved millisecond pulsars in the region of angular resolution of EGRET, the emissions of which could contribute significantly to the observed diffuse gamma‐rays in the Galactic Centre.