Temporal and spatial distributions of the unidentified EGRET sources
in the Galaxy
I. A. Grenier
Abstract
The large sample of unidentified EGRET sources in the 3rd catalogue pres
ents sources of obvious Galactic origin because of their concentration
along the Galactic plane. To question the origin of the 126 sources
scattered at medium and high latitudes, we have investigated both their
time variability and spatial distributions. To account for the instrumental
biases, the method developed earlier to study large scale correlations with
known populations (Grenier 1998) has been applied and the variability
results obtained by Tompkins (1999) have been used. It appears that the
spatial and temporal distributions are coupled, from which two populations
of sources may be distinguished. One of rather persistent sources presents
a significant correlation with the structure of the nearby Gould Belt. A
new population of variable Galactic sources arises from this study. Its
spatial distribution will be presented and discussed.
File translated from TEX by TTH, version 2.32.
On 16 Jul 1999, 09:19.