Satellite stellar-to-halo mass relations in primordial black hole universes
Abstract
Primordial black holes (PBHs), in particular with a fixed-conformal-time (FCT) extended mass function, can modify small-scale structure through enhanced primordial power and discreteness-driven Poisson fluctuations, altering subhalo abundances and internal structure. We study their effects on satellite stellar-to-halo mappings, bound-remnant compactness, and the link to compact dark perturbers. We compare two dark-matter-only simulations, a fiducial CDM run and an FCT/PBH run. As these runs form no galaxies, we construct an approximate abundance-based stellar-to-halo mapping using the progenitor virial mass at last isolation. The CDM mapping is anchored to a redshift-dependent abundance-matching stellar-to-halo relation, and the FCT mapping is derived from the relative cumulative subhalo abundances. We use resolved SOAP (V_max) and (R_max) to characterize present-day subhalo compactness, supplemented by a subgrid estimate of mass segregation in the unresolved PBH population. FCT enhances the subhalo abundance in a mass-dependent way, but abundance-based stellar-mass reassignment makes satellite stellar-mass functions weak discriminants. Internal structure is a stronger test: FCT subhaloes are more compact and have larger NFW-reconstructed enclosed masses at fixed radius, strengthening a Too-Big-To-Fail-like tension if all compact subhaloes host luminous satellites. FCT subhaloes also form earlier, accounting for much of the low-mass compactness difference, while PBH mass segregation adds a central perturbation with typical μ~ 0.4-0.5. Neither effect fully explains the resolved FCT compactness enhancement. Changes in the galaxy--halo mapping can partly hide the enhanced FCT subhalo abundance in satellite counts, whereas internal dynamics remain more discriminating. Satellite abundances, dynamics, and compact dark perturbers are complementary probes of PBH-induced small-scale structure.
Related
- Accretion of Primordial Black Holes in Stellar Interiors
- Physics-based phenomenological modeling of binary black hole hierarchical formation 1: Synthetic universes from globular cluster simulations for GWTC
- Investigating the formation of small Solar System objects using stellar occultations by satellites: present, future and its use to update satellite orbits
- Search for subsolar primordial black holes in low mass-ratio binaries with LIGO-Virgo O2 data and implications for the primordial black hole dark matter fraction
- Primordial black hole interpretation of the subsolar merger event S251112cm
BibTeX
@misc{colazo2026satellite,
title = {{Satellite stellar-to-halo mass relations in primordial black hole universes}},
author = {Patricio Colazo and Nelson Padilla and Federico Stasyszyn},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.35988},
eprint = {2609.35988},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.35988},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Satellite stellar-to-halo mass relations in primordial black hole universes
AU - Patricio Colazo
AU - Nelson Padilla
AU - Federico Stasyszyn
PY - 2026
DA - 2026/09/28
PB - arXiv
DO - 10.48550/arxiv.2609.35988
UR - https://arxiv.org/abs/2609.35988
AB - Primordial black holes (PBHs), in particular with a fixed-conformal-time (FCT) extended mass function, can modify small-scale structure through enhanced primordial power and discreteness-driven Poisson fluctuations, altering subhalo abundances and internal structure. We study their effects on satellite stellar-to-halo mappings, bound-remnant compactness, and the link to compact dark perturbers. We compare two dark-matter-only simulations, a fiducial CDM run and an FCT/PBH run. As these runs form no galaxies, we construct an approximate abundance-based stellar-to-halo mapping using the progenitor virial mass at last isolation. The CDM mapping is anchored to a redshift-dependent abundance-matching stellar-to-halo relation, and the FCT mapping is derived from the relative cumulative subhalo abundances. We use resolved SOAP (V_max) and (R_max) to characterize present-day subhalo compactness, supplemented by a subgrid estimate of mass segregation in the unresolved PBH population. FCT enhances the subhalo abundance in a mass-dependent way, but abundance-based stellar-mass reassignment makes satellite stellar-mass functions weak discriminants. Internal structure is a stronger test: FCT subhaloes are more compact and have larger NFW-reconstructed enclosed masses at fixed radius, strengthening a Too-Big-To-Fail-like tension if all compact subhaloes host luminous satellites. FCT subhaloes also form earlier, accounting for much of the low-mass compactness difference, while PBH mass segregation adds a central perturbation with typical μ~ 0.4-0.5. Neither effect fully explains the resolved FCT compactness enhancement. Changes in the galaxy--halo mapping can partly hide the enhanced FCT subhalo abundance in satellite counts, whereas internal dynamics remain more discriminating. Satellite abundances, dynamics, and compact dark perturbers are complementary probes of PBH-induced small-scale structure.
ER -