26–30 juil. 2010
Montpellier 2 University
Fuseau horaire Europe/Paris

The observational signatures of high-redshift dark stars

29 juil. 2010, 13:40
20m
Amphithéatre Dumontet (Montpellier 2 University)

Amphithéatre Dumontet

Montpellier 2 University

Place Eugene Bataillon, 34095 Montpellier Cedex 5 FRANCE

Orateur

Dr Erik Zackrisson (Stockholm Observatory)

Description

The annihilation of dark matter particles in the centers of minihalos may lead to the formation of so-called dark stars, which are cooler, larger, more massive and potentially more long-lived than conventional population III stars. Here, we investigate the prospects of detecting high-redshift dark stars with upcoming James Webb Space Telescope (JWST). We find that individual dark stars with masses below 1000 Msolar are intrinsically too faint for JWST. However, by exploiting foreground galaxy clusters as gravitational telescopes, certain varieties of dark stars should be within range at z~10-15. Since the JWST colours of these objects are very different from those of mundane interlopers in front of, within or behind the lensing clusters, such dark stars should be readily identifiable in JWST imaging surveys. We also argue that, if the the life times of dark stars are sufficiently long, many such objects may congregate inside the first galaxies. This could give rise to peculiar features in the integrated spectra of high-redshift galaxies.

Auteur principal

Dr Erik Zackrisson (Stockholm Observatory)

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