Stability and pulsation of the first dark stars

Autor(en)

Tanja Rindler-Daller, Katherine Freese, Richard H. D. Townsend, Luca Visinelli

Abstrakt

The first bright objects to form in the Universe might not have been 'ordinary' fusion-powered stars, but 'dark stars' (DSs) powered by the annihilation of dark matter (DM) in the form of weakly interacting massive particles (WIMPs). If discovered, DSs can provide a unique laboratory to test DM models. DSs are born with a mass of the order of M_⊙ and may grow to a few million solar masses; in this work we investigate the properties of early DSs with masses up to ∼1000M_⊙ , fueled by WIMPS weighing 100 GeV. We improve the previous implementation of the DM energy source into the stellar evolution code MESA. We show that the growth of DSs is not limited by astrophysical effects: DSs up to ∼1000M_⊙ exhibit no dynamical instabilities; DSs are not subject to mass-loss driven by super-Eddington winds. We test the assumption of previous work that the injected energy per WIMP annihilation is constant throughout the star; relaxing this assumption does not change the properties of the DSs. Furthermore, we study DS pulsations, for the first time investigating non-adiabatic pulsation modes, using the linear pulsation code GYRE. We find that acoustic modes in DSs of masses smaller than ∼200M_⊙ are excited by the κ - γ and γ mechanism in layers where hydrogen or helium is (partially) ionized. Moreover, we show that the mass-loss rates potentially induced by pulsations are negligible compared to the accretion rates.

Organisation(en)

Institut für Astrophysik

Externe Organisation(en)

University of Texas, Austin, University of Amsterdam (UvA), Stockholm University, University of Wisconsin, Madison

Journal

Monthly Notices of the Royal Astronomical Society

Band

503

Seiten

3677-3691

Anzahl der Seiten

15

ISSN

0035-8711

DOI

https://doi.org/10.1093/mnras/stab420

Publikationsdatum

05-2021

Peer-reviewed

Ja

ÖFOS 2012

103003 Astronomie, 103004 Astrophysik, 103044 Kosmologie

Schlagwörter

ASJC Scopus Sachgebiete

Astronomy and Astrophysics, Space and Planetary Science

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/c930746f-7bbf-4e57-99f6-b39574ca4f7d