4. Concluding remarks
As can be seen from the figures, the distribution of the accretion luminosity in R-Z plane forms a toroidal (ring) structure with maximum at approximately 5 kpc.
As expected, BH give higher luminosity than NS, as they have greater masses. But if the total number of BH is significantly lower than the number of NS, their contribution to the luminosity can be less than the contribution of NS. The total accretion lumiunosity of the Galaxy for and is about erg/s. For a characteristic velocity of 200 km/s the maximum of the distribution is situated approximately at 5.0 kpc for NS and at 4.8 kpc for BH. For NS with a characteristic velocity of 400 km/s maximum is located at 5.5 kpc, and for BH at 5.0 kpc. This result is also expected because of the higher masses of the BH.
The toroidal structure of the luminosity distribution of NS and BH is an interesting and important feature of the Galactic potential. As one can expect, for low characteristic kick velocities and for BH we have a higher luminosity.
As we made very general assumptions, we argue, that such a distribution is not unique for our Galaxy, and all spiral galaxies can have such a distribution of the accretion luminosity, associated with accreting NS and BH.
© European Southern Observatory (ESO) 1998
Online publication: February 16, 1998