Heavy neutrino ball as a possible solution to the "blackness problem" of the galactic center

It has been recently shown (Tsiklauri & Viollier, 1998a) that the matter concentration inferred from observed stellar motion at the galactic center (Eckart & Genzel, 1997, MNRAS, 284, 576 and Genzel et al., 1996, ApJ, 472, 153) is consistent with a supermassive object of $2.5 \times 10^6$ solar masses, composed of self-gravitating, degenerate heavy neutrinos. It has been furthermore suggested (Tsiklauri & Viollier, 1998a) that the neutrino ball scenario may have the distinct advantage that it could naturally explain the so-called "blackness problem" of the galactic center. Here, we present a quantitative proof of this statement, by calculating the emitted spectrum of Sgr A$^*$ in the framework of standard accretion disk theory.