Strong lensing signatures of self-interacting dark matter in low-mass haloes
| Autor: | Simon Birrer, Tommaso Treu, Andrew J. Benson, Jo Bovy, Anna Nierenberg, Daniel Gilman, Omid Sameie |
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| Rok vydání: | 2021 |
| Předmět: |
Physics
Cosmology and Nongalactic Astrophysics (astro-ph.CO) Cold dark matter 010308 nuclear & particles physics Self-interacting dark matter Image (category theory) Dark matter FOS: Physical sciences Astronomy and Astrophysics Quasar Astrophysics::Cosmology and Extragalactic Astrophysics Astrophysics 01 natural sciences Galaxy Amplitude 13. Climate action Space and Planetary Science 0103 physical sciences Elliptical galaxy 010303 astronomy & astrophysics Astrophysics::Galaxy Astrophysics Astrophysics - Cosmology and Nongalactic Astrophysics |
| Zdroj: | Monthly Notices of the Royal Astronomical Society. 507:2432-2447 |
| ISSN: | 1365-2966 0035-8711 |
| Popis: | Core formation and runaway core collapse in models with self-interacting dark matter (SIDM) significantly alter the central density profiles of collapsed halos. Using a forward modeling inference framework with simulated datasets, we demonstrate that flux ratios in quadruple image strong gravitational lenses can detect the unique structural properties of SIDM halos, and statistically constrain the amplitude and velocity dependence of the interaction cross section in halos with masses between $10^6 - 10^{10} M_{\odot}$. Measurements on these scales probe self-interactions at velocities below $30 \ \rm{km} \ \rm{s^{-1}}$, a relatively unexplored regime of parameter space, complimenting constraints at higher velocities from galaxies and clusters. We cast constraints on the amplitude and velocity dependence of the interaction cross section in terms of $\sigma_{20}$, the cross section amplitude at $20 \ \rm{km} \ \rm{s^{-1}}$. With 50 lenses, a sample size available in the near future, and flux ratios measured from spatially compact mid-IR emission around the background quasar, we forecast $\sigma_{20} < 11-23 \ \rm{cm^2} \rm{g^{-1}}$ at $95 \%$ CI, depending on the amplitude of the subhalo mass function, and assuming cold dark matter (CDM). Alternatively, if $\sigma_{20} = 19.2 \ \rm{cm^2}\rm{g^{-1}}$ we can rule out CDM with a likelihood ratio of 20:1, assuming an amplitude of the subhalo mass function that results from doubly-efficient tidal disruption in the Milky Way relative to massive elliptical galaxies. These results demonstrate that strong lensing of compact, unresolved sources can constrain SIDM structure on sub-galactic scales across cosmological distances, and the evolution of SIDM density profiles over several Gyr of cosmic time. Comment: matches version accepted to MNRAS |
| Databáze: | OpenAIRE |
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