21–23 Feb 2018
UCLA Faculty Center
America/Los_Angeles timezone
Regular registration is now open

Katherine Freese (U Michigan): Dark Stars

22 Feb 2018, 08:50
14m
Talk Session 5

Speaker

Katherine Freese (University of Michigan)

Description

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 are their own antipartners can collect inside the first stars and annihilate to produce a heat source that powers the stars. A new stellar phase results, a Dark Star, which lasts as long as there is dark matter fuel, with lifetimes from millions to billions of years. Dark Stars, while made primarily of hydrogen and helium, are powered by dark matter. They are very bright diffuse puffy objects and grow to be very massive. In fact, they can grow up to ten million solar masses with up to ten billion solar luminosities. Such objects can be seen in James Webb Space Telescope; their signatures will be discussed. 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 in galaxies today. The black holes could still have dark matter spikes around them so that gamma-rays and positrons from annihilation could be seen in a variety of experiments.

Presentation materials