SIDM on fire: hydrodynamical self-interacting dark matter simulations of low-mass dwarf galaxies
| Autor: | James S. Bullock, Victor H. Robles, Christopher C. Hayward, Michael Boylan-Kolchin, Alejandro González-Samaniego, Philip F. Hopkins, Dušan Kereš, Claude André Faucher-Giguère, Oliver D. Elbert, Alex Fitts |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
Physics
Cold dark matter Stellar mass 010308 nuclear & particles physics Self-interacting dark matter Dark matter FOS: Physical sciences Local Group Astronomy Astronomy and Astrophysics Astrophysics::Cosmology and Extragalactic Astrophysics Astrophysics Astrophysics - Astrophysics of Galaxies 01 natural sciences Article Galaxy Space and Planetary Science Astrophysics of Galaxies (astro-ph.GA) 0103 physical sciences Galaxy formation and evolution 010303 astronomy & astrophysics Astrophysics::Galaxy Astrophysics Dwarf galaxy |
| Zdroj: | NASA Astrophysics Data System |
| ISSN: | 1365-2966 0035-8711 |
| Popis: | We compare a suite of four simulated dwarf galaxies formed in 10$^{10} M_{\odot}$ haloes of collisionless Cold Dark Matter (CDM) with galaxies simulated in the same haloes with an identical galaxy formation model but a non-zero cross-section for dark matter self-interactions. These cosmological zoom-in simulations are part of the Feedback In Realistic Environments (FIRE) project and utilize the FIRE-2 model for hydrodynamics and galaxy formation physics. We find the stellar masses of the galaxies formed in Self-Interacting Dark Matter (SIDM) with $\sigma/m= 1\, cm^2/g$ are very similar to those in CDM (spanning $M_{\star} \approx 10^{5.7 - 7.0} M_{\odot}$) and all runs lie on a similar stellar mass -- size relation. The logarithmic dark matter density slope ($\alpha=d\log \rho / d\log r$) in the central $250-500$ pc remains steeper than $\alpha= -0.8$ for the CDM-Hydro simulations with stellar mass $M_{\star} \sim 10^{6.6} M_{\odot}$ and core-like in the most massive galaxy. In contrast, every SIDM hydrodynamic simulation yields a flatter profile, with $\alpha >-0.4$. Moreover, the central density profiles predicted in SIDM runs without baryons are similar to the SIDM runs that include FIRE-2 baryonic physics. Thus, SIDM appears to be much more robust to the inclusion of (potentially uncertain) baryonic physics than CDM on this mass scale, suggesting SIDM will be easier to falsify than CDM using low-mass galaxies. Our FIRE simulations predict that galaxies less massive than $M_{\star} < 3 \times 10^6 M_{\odot}$ provide potentially ideal targets for discriminating models, with SIDM producing substantial cores in such tiny galaxies and CDM producing cusps. Comment: 10 Pages, 7 figures, submitted to MNRAS |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|