Paraphrasing a famous physicist who was talking about
quantum mechanics, anyone who isn't astonished and
even a bit frightened at the implications of over 70% of
the Universe being made of totally different matter from
what we are accustomed to - and it may be countless
ancient black holes at that - does not understand or
appreciate the situation.

Primordial black holes and the observed Galactic 511 keV line

Authors: Cosimo Bambi, Alexander D. Dolgov, Alexey A. Petrov

(Submitted on 17 Jan 2008)

Abstract: The observed 511 keV line from the Galactic Bulge is a real challenge for theoretical astrophysics: despite a lot of suggested mechanisms, there is still no convincing explanation and the origin of the annihilated positrons remains unknown. Here we discuss the possibility that a population of slowly evaporating primordial black holes with the mass around $10^{16}$ g ejects (among other particles) low--energy positrons into the Galaxy. In addition to positrons, we have also calculated the spectrum and number density of photons and neutrinos produced by such black holes and found that the photons are potentially observable in the near future, while the neutrino flux is too weak and below the terrestrial and extra--terrestrial backgrounds. Depending on their mass distribution, such black holes could make a small fraction or the whole cosmological dark matter.

Comments: 5 pages, 7 figures

Subjects: Astrophysics (astro-ph); High Energy Physics -
Phenomenology (hep-ph)

Report number: WSU-HEP-0801

Cite as: arXiv:0801.2786v1 [astro-ph]

Submission history

From: Cosimo Bambi [view email]

[v1] Thu, 17 Jan 2008 22:29:16 GMT (513kb)

http://arxiv.org/abs/0801.2786