2025/09/30 by Konstantinos Topalakis, Devesh Nandal, Topalakis, Konstantinos +3
Physics and Astronomy · #Astro and Planetary Science #Astrophysics and Star Formation Studies #Astrophysics of Galaxies (astro-ph.GA) #Cosmology and Nongalactic Astrophysics (astro-ph.CO) #FOS: Physical sciences #High Energy Astrophysical Phenomena (astro-ph.HE) #High Energy Physics - Phenomenology (hep-ph) #Solar and Stellar Astrophysics (astro-ph.SR) #Stellar, planetary, and galactic studies
paper · pdf · doi:10.48550/arxiv.2510.00216
openalex publication_date 2025/09/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The rapid appearance of supermassive black holes (SMBHs) at z\gtrsim7 requires efficient pathways to form massive black hole seeds. We investigate whether annihilation of weakly interacting massive particles (WIMPs) can alter primordial (Pop III.1) protostellar evolution sufficiently to enable formation of such `heavy'' seeds. Using the one-dimensional Geneva stellar-evolution code (GENEC) with an implemented Gould single-scatter capture module, we compute a grid of protostellar evolution models covering ambient WIMP mass densities ρχ=1012-1016 \mathrmGeV cm-3, WIMP masses mχ=30-3000 GeV, spin-dependent cross sections σ\rm SD=10-42-10-40 cm2, and baryonic accretion rates M_*=(1-3)×10-3 M_\odot \rm yr-1. We find a robust bifurcation of outcomes. For sufficiently high ambient dark matter density (ρχ\gtrsim5×1014 \mathrmGeV cm-3) and capture efficiency (σ\rm SD\gtrsim10-41 cm2) WIMP annihilation supplies enough energy to inflate protostars onto extended, cool (Hayashi-track) configurations that dramatically suppress ionizing feedback and permit uninterrupted growth to ∼105 M_\odot. Lighter WIMPs and larger σ\rm SD favour earlier and stronger annihilation support; heavier WIMPs delay the effect. For our fiducial case, WIMP masses <3 TeV are essential for allowing growth to the supermassive regime, otherwise the protostar evolves to the compact, feedback-limited regime that results in `light'' seeds. These results indicate that, under plausible halo conditions, DM annihilation provides a viable channel for forming heavy black hole seeds.