Effects of axions on Population III stars

Abstract

Following the renewed interest for axions as a dark matter component, we revisit the effects of energy loss by axion emission on the evolution of the first generation of stars. These stars with zero metallicity are supposed to be massive, more compact, and hotter than subsequent generations. It is hence important to extend previous studies restricted to solar metallicity stars. Our analysis first compares the evolution of solar metallicity 8, 10 and 12 M${}_{\odot }$ stars to previous work. We then calculate the evolution of 8 zero metallicity stars with and without axion losses and with masses ranging from 20 to 150 M${}_{\odot }$. For the solar metallicity models, we confirm the disappearance of the blue loop phase for a value of the axion-photon coupling, $g_{a\gamma }=10^{-10}{\mathrm{GeV}}^{-1}$. Regarding the Pop. III stars, we show that for $g_{a\gamma }=10^{-10}{\mathrm{GeV}}^{-1}$, their evolution is not much affected by axion losses except within the range of masses 80$-$130 M${}_{\odot }$. Such stars show significant differences both in their tracks within the $T_c$-${\rho }_c$ diagram and in their central composition (in particular ${}^{20}$Ne and ${}^{24}$Mg). We discuss the origin of these modifications from the stellar physics point of view, and their potential observational signatures.

10 pages, 11 figures, accepted for publication in A&A

References in corpus (7)

• Pulsational Pair-Instability Supernovae
• Revisiting the bound on axion-photon coupling from Globular Clusters
• Effects of rotation on the evolution of primordial stars
• Constraining the Axion-Photon Coupling with Massive Stars
• Neon Abundances in B-Stars of the Orion Association: Solving the Solar Model Problem?
• On the Blue Loops of Intermediate-Mass Stars
• Can very massive stars avoid Pair-Instability Supernovae?

Cited by in corpus (7)

• Axion Astrophysics
• Rapidly rotating Population III stellar models as a source of primary nitrogen
• Elimination of the Blue Loops in the Evolution of Intermediate-mass Stars by the Neutrino Magnetic Moment and Large Extra Dimensions
• Asteroseismology: Looking for axions in the red supergiant star Alpha Ori
• Light Axion Emission and the Formation of Merging Binary Black Holes
• Blue Loops, Cepheids, and Forays into Axions
• Constraints on the Axion-Photon Coupling Using Stellar Modelling