Strong Dark Matter Self-interactions Diversify Halo Populations within and surrounding the Milky Way
We perform a high-resolution cosmological zoom-in simulation of a Milky Way (MW)–like system, which includes a realistic Large Magellanic Cloud analog, using a large differential elastic dark matter self-interaction cross section that reaches ≈100 cm ^2 g ^−1 at relative velocities of ≈10 km s ^−1 ,...
| Main Authors: | , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
IOP Publishing
2023-01-01
|
| Series: | The Astrophysical Journal |
| Subjects: | |
| Online Access: | https://doi.org/10.3847/1538-4357/acc73e |
| _version_ | 1797699862733520896 |
|---|---|
| author | Daneng Yang Ethan O. Nadler Hai-Bo Yu |
| author_facet | Daneng Yang Ethan O. Nadler Hai-Bo Yu |
| author_sort | Daneng Yang |
| collection | DOAJ |
| description | We perform a high-resolution cosmological zoom-in simulation of a Milky Way (MW)–like system, which includes a realistic Large Magellanic Cloud analog, using a large differential elastic dark matter self-interaction cross section that reaches ≈100 cm ^2 g ^−1 at relative velocities of ≈10 km s ^−1 , motivated by the diverse and orbitally dependent central densities of dwarf galaxies within and surrounding the MW. We explore the effects of dark matter self-interactions on satellite, splashback, and isolated halos through their abundance, central densities, maximum circular velocities, orbital parameters, and correlations between these variables. We use an effective constant cross section model to analytically predict the stages of our simulated halos’ gravothermal evolution, demonstrating that deviations from the collisionless ${R}_{\max }$ – ${V}_{\max }$ relation can be used to select deeply core-collapsed halos, where ${V}_{\max }$ is a halo’s maximum circular velocity, and ${R}_{\max }$ is the radius at which it occurs. We predict that a sizable fraction (≈20%) of subhalos with masses down to ≈10 ^8 M _⊙ is deeply core collapsed in our SIDM model. Core-collapsed systems form ≈10% of the isolated halo population down to the same mass; these isolated, core-collapsed halos would host faint dwarf field galaxies with extremely steep central density profiles. Finally, most halos with masses above ≈10 ^9 M _⊙ are core-forming in our simulation. Our study thus demonstrates how self-interactions diversify halo populations in an environmentally dependent fashion within and surrounding MW-mass hosts, providing a compelling avenue to address the diverse dark matter distributions of observed dwarf galaxies. |
| first_indexed | 2024-03-12T04:13:56Z |
| format | Article |
| id | doaj.art-74c2f9c94c744b05863e5075d8e0b1fc |
| institution | Directory Open Access Journal |
| issn | 1538-4357 |
| language | English |
| last_indexed | 2024-03-12T04:13:56Z |
| publishDate | 2023-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | The Astrophysical Journal |
| spelling | doaj.art-74c2f9c94c744b05863e5075d8e0b1fc2023-09-03T10:44:25ZengIOP PublishingThe Astrophysical Journal1538-43572023-01-0194926710.3847/1538-4357/acc73eStrong Dark Matter Self-interactions Diversify Halo Populations within and surrounding the Milky WayDaneng Yang0https://orcid.org/0000-0002-5421-3138Ethan O. Nadler1https://orcid.org/0000-0002-1182-3825Hai-Bo Yu2https://orcid.org/0000-0002-8421-8597Department of Physics and Astronomy, University of California , Riverside, CA 92521, USA ; danengy@ucr.eduCarnegie Observatories , 813 Santa Barbara Street, Pasadena, CA 91101, USA ; enadler@carnegiescience.edu; Department of Physics & Astronomy, University of Southern California , Los Angeles, CA 90007, USA ; haiboyu@ucr.eduDepartment of Physics and Astronomy, University of California , Riverside, CA 92521, USA ; danengy@ucr.eduWe perform a high-resolution cosmological zoom-in simulation of a Milky Way (MW)–like system, which includes a realistic Large Magellanic Cloud analog, using a large differential elastic dark matter self-interaction cross section that reaches ≈100 cm ^2 g ^−1 at relative velocities of ≈10 km s ^−1 , motivated by the diverse and orbitally dependent central densities of dwarf galaxies within and surrounding the MW. We explore the effects of dark matter self-interactions on satellite, splashback, and isolated halos through their abundance, central densities, maximum circular velocities, orbital parameters, and correlations between these variables. We use an effective constant cross section model to analytically predict the stages of our simulated halos’ gravothermal evolution, demonstrating that deviations from the collisionless ${R}_{\max }$ – ${V}_{\max }$ relation can be used to select deeply core-collapsed halos, where ${V}_{\max }$ is a halo’s maximum circular velocity, and ${R}_{\max }$ is the radius at which it occurs. We predict that a sizable fraction (≈20%) of subhalos with masses down to ≈10 ^8 M _⊙ is deeply core collapsed in our SIDM model. Core-collapsed systems form ≈10% of the isolated halo population down to the same mass; these isolated, core-collapsed halos would host faint dwarf field galaxies with extremely steep central density profiles. Finally, most halos with masses above ≈10 ^9 M _⊙ are core-forming in our simulation. Our study thus demonstrates how self-interactions diversify halo populations in an environmentally dependent fashion within and surrounding MW-mass hosts, providing a compelling avenue to address the diverse dark matter distributions of observed dwarf galaxies.https://doi.org/10.3847/1538-4357/acc73eDark matterGalaxy abundancesN-body simulationsGalaxy dark matter halosComputational methods |
| spellingShingle | Daneng Yang Ethan O. Nadler Hai-Bo Yu Strong Dark Matter Self-interactions Diversify Halo Populations within and surrounding the Milky Way The Astrophysical Journal Dark matter Galaxy abundances N-body simulations Galaxy dark matter halos Computational methods |
| title | Strong Dark Matter Self-interactions Diversify Halo Populations within and surrounding the Milky Way |
| title_full | Strong Dark Matter Self-interactions Diversify Halo Populations within and surrounding the Milky Way |
| title_fullStr | Strong Dark Matter Self-interactions Diversify Halo Populations within and surrounding the Milky Way |
| title_full_unstemmed | Strong Dark Matter Self-interactions Diversify Halo Populations within and surrounding the Milky Way |
| title_short | Strong Dark Matter Self-interactions Diversify Halo Populations within and surrounding the Milky Way |
| title_sort | strong dark matter self interactions diversify halo populations within and surrounding the milky way |
| topic | Dark matter Galaxy abundances N-body simulations Galaxy dark matter halos Computational methods |
| url | https://doi.org/10.3847/1538-4357/acc73e |
| work_keys_str_mv | AT danengyang strongdarkmatterselfinteractionsdiversifyhalopopulationswithinandsurroundingthemilkyway AT ethanonadler strongdarkmatterselfinteractionsdiversifyhalopopulationswithinandsurroundingthemilkyway AT haiboyu strongdarkmatterselfinteractionsdiversifyhalopopulationswithinandsurroundingthemilkyway |