SIMBAD references

We have studied a number of galactic open clusters that lie in the error boxes of COS B sources. These clusters belong to complexes in which similar star formation processes occur. They have similar ages, stellar population and contain peculiar stars with very high-velocity stellar winds. We propose that a system of shock fronts, set up at the interfaces between the hypersonic wind of the peculiar stars and the other cluster members, generates acceleration of cosmic ray particles, whose interactions with the inter-cluster gas concentrations would be responsible for the observed γ-ray emission. We find various observational evidences (including CGRO data, strongly supporting the association of the γ-ray source J 2021+37=2CG075+00 with Berk 87) for the presence of such shock fronts in some of these clusters. We show that the diffuse hard X-ray emission from the clusters regions is consistent with the geometric scenario inferred from the data and with the assumed mechanism of cosmic ray acceleration.