SMF Cutoff

[ROBERT L OLDERSHAW]

Bahcall et al (ApJ 435,L51,1994) recently observed an apparent
cutoff at the lower mass end of the stellar mass function (SMF) in
the Galaxy. Paresce et al (ApJ 440,216,1995 and 442,L57,1995) have
two, possibly three, observations of equivalent cutoff phenomena
in gobular clusters. In Science (25 NOV 1994, p. 1319), J. Travis
wrote a Research News piece on these results, which included a summary
graph of the lower SMF results.

There is a clear upturn that rises to a peak at about 0.15 solar
masses. Below this peak there is a steep decline that persists to
the limit of the survey at 0.10 solar masses. The SMF cutoff casts
doubt on "brown dwarfs" as dark matter candidates and leaves many
astronomers asking why there is a cutoff and "why does nature pick
this mass [about 0.15 solar masses] for the turnover?

As early as 1987, a little known cosmological model based on a
fractal paradigm predicted that the SMF would have a major peak at
0.145 solar masses, a sharp decline below this, and no substantial
rise until another large, discrete peak at about 7x10(exp -5) solar
masses (ApJ 322,34,1987; Internat. J. Theor. Phys. 28,669 and 1503,
1989). This model also predicted MACHO objects at 0.15 solar masses
(1987) and pulsar/planet systems (1989). I hope these observations and
predictions are of interest to other scientists.