2 research outputs found
Dark Stars: A New Study of the FIrst Stars in the Universe
We have proposed that the first phase of stellar evolution in the history of
the Universe may be Dark Stars (DS), powered by dark matter heating rather than
by nuclear fusion. Weakly Interacting Massive Particles, which may be their own
antipartners, collect inside the first stars and annihilate to produce a heat
source that can power the stars. A new stellar phase results, a Dark Star,
powered by dark matter annihilation as long as there is dark matter fuel, with
lifetimes from millions to billions of years. We find that the first stars are
very bright () and cool (K) during the DS
phase, and grow to be very massive (500-1000 times as massive as the Sun).
These results differ markedly from the standard picture in the absence of DM
heating, in which the maximum mass is about 140 and the temperatures
are much hotter (K); hence DS should be observationally
distinct from standard Pop III stars. Once the dark matter fuel is exhausted,
the DS becomes a heavy main sequence star; these stars eventually collapse to
form massive black holes that may provide seeds for supermassive black holes
observed at early times as well as explanations for recent ARCADE data and for
intermediate black holes.Comment: article to be published in special issue on Dark Matter and Particle
Physics in New Journal of Physic
The Formation of the First Massive Black Holes
Supermassive black holes (SMBHs) are common in local galactic nuclei, and
SMBHs as massive as several billion solar masses already exist at redshift z=6.
These earliest SMBHs may grow by the combination of radiation-pressure-limited
accretion and mergers of stellar-mass seed BHs, left behind by the first
generation of metal-free stars, or may be formed by more rapid direct collapse
of gas in rare special environments where dense gas can accumulate without
first fragmenting into stars. This chapter offers a review of these two
competing scenarios, as well as some more exotic alternative ideas. It also
briefly discusses how the different models may be distinguished in the future
by observations with JWST, (e)LISA and other instruments.Comment: 47 pages with 306 references; this review is a chapter in "The First
Galaxies - Theoretical Predictions and Observational Clues", Springer
Astrophysics and Space Science Library, Eds. T. Wiklind, V. Bromm & B.
Mobasher, in pres