2018/09/30 by Rouven Essig, Samuel D. McDermott, Hai-Bo Yu +1 · 2 citations
Physics and Astronomy · #astro-ph.CO #astro-ph.GA #hep-ph
paper · pdf · doi:10.1103/physrevlett.123.121102
published as Phys. Rev. Lett. 123, 121102 (2019) · v2 as published in PRL
arxiv created 2019/09/21 · arxiv updated 2019/09/25
We study the gravothermal evolution of dark matter halos in the presence of dissipative dark matter self-interactions. Dissipative interactions are present in many particle-physics realizations of the dark-sector paradigm and can significantly accelerate the gravothermal collapse of halos compared to purely elastic dark matter self-interactions. This is the case even when the dissipative interaction timescale is longer than the free-fall time of the halo. Using a semianalytical fluid model calibrated with isolated and cosmological N-body simulations, we calculate the evolution of the halo properties -- including its density profile and velocity dispersion profile -- as well as the core-collapse time as a function of the particle model parameters that describe the interactions. A key property is that the inner density profile at late times becomes cuspy again. Using 18 dwarf galaxies that exhibit a corelike dark matter density profile, we derive constraints on the strength of the dissipative interactions and the energy loss per collision.