  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 an advantage that it could possibly explain the so-called
"blackness problem" of the galactic center. Here, we present a quantitative
investigation of this statement, by calculating the emitted spectrum of Sgr
A$^*$ in the framework of standard accretion disk theory.
