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Selfinteracting dark matter halos and the gravothermal catastrophe

4 Pith papers cite this work. Polarity classification is still indexing.

4 Pith papers citing it
abstract

We study the evolution of an isolated, spherical halo of self-interacting dark matter (SIDM) in the gravothermal fluid formalism. We show that the thermal relaxation time, $t_r$, of a SIDM halo with a central density and velocity dispersion of a typical dwarf galaxy is significantly shorter than its age. We find a self-similar solution for the evolution of a SIDM halo in the limit where the mean free path between collisions, $\lambda$, is everywhere longer than the gravitational scale height, $H$. Typical halos formed in this long mean free path regime relax to a quasistationary gravothermal density profile characterized by a nearly homogeneous core and a power-law halo where $\rho \propto r^{-2.19}$. We solve the more general time-dependent problem and show that the contracting core evolves to sufficiently high density that $\lambda$ inevitably becomes smaller than $H$ in the innermost region. The core undergoes secular collapse to a singular state (the ``gravothermal catastrophe'') in a time $t_{coll} \approx 290 t_r$, which is longer than the Hubble time for a typical dark matter-dominated galaxy core at the present epoch. Our model calculations are consistent with previous, more detailed, N-body simulations for SIDM, providing a simple physical interpretation of their results and extending them to higher spatial resolution and longer evolution times. At late times, mass loss from the contracting, dense inner core to the ambient halo is significantly moderated, so that the final mass of the inner core may be appreciable when it becomes relativistic and radially unstable to dynamical collapse to a black hole.

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2026 3 2025 1

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UNVERDICTED 4

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representative citing papers

Role of prompt cusps in driving the core collapse of SIDM halos

astro-ph.GA · 2025-11-28 · unverdicted · novelty 7.0

Prompt cusps delay core formation by a factor of ~2 in SIDM halos but later collapse tracks align after rescaling, with ~5% late-stage deviations depending on concentration and outer velocity dispersion.

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Showing 4 of 4 citing papers.