Orientations of Dark Matter Halos in FIRE-2 Milky Way–mass Galaxies
The shape and orientation of dark matter (DM) halos are sensitive to the microphysics of the DM particles, yet in many mass models, the symmetry axes of the Milky Way’s DM halo are often assumed to be aligned with the symmetry axes of the stellar disk. This is well motivated for the inner DM halo, b...
| 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/acea79 |
| _version_ | 1797632394641014784 |
|---|---|
| author | Jay Baptista Robyn Sanderson Dan Huber Andrew Wetzel Omid Sameie Michael Boylan-Kolchin Jeremy Bailin Philip F. Hopkins Claude-André Faucher-Giguere Sukanya Chakrabarti Drona Vargya Nondh Panithanpaisal Arpit Arora Emily Cunningham |
| author_facet | Jay Baptista Robyn Sanderson Dan Huber Andrew Wetzel Omid Sameie Michael Boylan-Kolchin Jeremy Bailin Philip F. Hopkins Claude-André Faucher-Giguere Sukanya Chakrabarti Drona Vargya Nondh Panithanpaisal Arpit Arora Emily Cunningham |
| author_sort | Jay Baptista |
| collection | DOAJ |
| description | The shape and orientation of dark matter (DM) halos are sensitive to the microphysics of the DM particles, yet in many mass models, the symmetry axes of the Milky Way’s DM halo are often assumed to be aligned with the symmetry axes of the stellar disk. This is well motivated for the inner DM halo, but not for the outer halo. We use zoomed-in cosmological baryonic simulations from the Latte suite of FIRE-2 Milky Way–mass galaxies to explore the evolution of the DM halo’s orientation with radius and time, with or without a major merger with a Large Magellanic Cloud analog, and when varying the DM model. In three of the four cold DM halos we examine, the orientation of the halo minor axis diverges from the stellar disk vector by more than 20° beyond about 30 galactocentric kpc, reaching a maximum of 30°–90°, depending on the individual halo’s formation history. In identical simulations using a model of self-interacting DM with σ = 1 cm ^2 g ^−1 , the halo remains aligned with the stellar disk out to ∼200–400 kpc. Interactions with massive satellites ( M ≳ 4 × 10 ^10 M _⊙ at pericenter; M ≳ 3.3 × 10 ^10 M _⊙ at infall) affect the orientation of the halo significantly, aligning the halo’s major axis with the satellite galaxy from the disk to the virial radius. The relative orientation of the halo and disk beyond 30 kpc is a potential diagnostic of self-interacting DM, if the effects of massive satellites can be accounted for. |
| first_indexed | 2024-03-11T11:37:22Z |
| format | Article |
| id | doaj.art-282059dc446c4407bba32fe7a3c84f63 |
| institution | Directory Open Access Journal |
| issn | 1538-4357 |
| language | English |
| last_indexed | 2024-03-11T11:37:22Z |
| publishDate | 2023-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | The Astrophysical Journal |
| spelling | doaj.art-282059dc446c4407bba32fe7a3c84f632023-11-10T12:47:05ZengIOP PublishingThe Astrophysical Journal1538-43572023-01-0195814410.3847/1538-4357/acea79Orientations of Dark Matter Halos in FIRE-2 Milky Way–mass GalaxiesJay Baptista0https://orcid.org/0000-0002-9306-1704Robyn Sanderson1https://orcid.org/0000-0003-3939-3297Dan Huber2https://orcid.org/0000-0001-8832-4488Andrew Wetzel3https://orcid.org/0000-0003-0603-8942Omid Sameie4https://orcid.org/0000-0003-4394-6085Michael Boylan-Kolchin5https://orcid.org/0000-0002-9604-343XJeremy Bailin6https://orcid.org/0000-0001-6380-010XPhilip F. Hopkins7https://orcid.org/0000-0003-3729-1684Claude-André Faucher-Giguere8https://orcid.org/0000-0002-4900-6628Sukanya Chakrabarti9https://orcid.org/0000-0001-6711-8140Drona Vargya10Nondh Panithanpaisal11https://orcid.org/0000-0001-5214-8822Arpit Arora12https://orcid.org/0000-0002-8354-7356Emily Cunningham13https://orcid.org/0000-0002-6993-0826Department of Astronomy and Astrophysics, Yale University , New Haven, CT 06520, USA ; jaymarie@stanford.edu; Institute for Astronomy, University of Hawai‘i , 2680 Woodlawn Drive, Honolulu, HI 96822, USA; Department of Physics, Stanford University , Stanford, CA 94305, USADepartment of Physics & Astronomy, University of Pennsylvania , Philadelphia, PA 19104, USA; Center for Computational Astrophysics, Flatiron Institute , New York, NY 10010, USAInstitute for Astronomy, University of Hawai‘i , 2680 Woodlawn Drive, Honolulu, HI 96822, USADepartment of Physics and Astronomy, University of California , Davis, CA 95616, USADepartment of Astronomy, The University of Texas Austin , 2515 Speedway, Stop C1400, Austin, TX 78712, USADepartment of Astronomy, The University of Texas Austin , 2515 Speedway, Stop C1400, Austin, TX 78712, USADepartment of Physics and Astronomy, University of Alabama , Box 870324, Tuscaloosa, AL 35487, USATAPIR, California Institute of Technology , MC 350-17, Pasadena, CA 91125, USADepartment of Physics and Astronomy and CIERA, Northwestern University , 1800 Sherman Avenue, Evanston, IL 60201, USASchool of Physics and Astronomy, University of Alabama , Huntsville, 301 Sparkman Drive, Huntsville, AL 35899, USA; Institute of Advanced Study , 1 Einstein Drive, Princeton, New Jersey 08540, USADepartment of Physics & Astronomy, University of Pennsylvania , Philadelphia, PA 19104, USADepartment of Physics & Astronomy, University of Pennsylvania , Philadelphia, PA 19104, USADepartment of Physics & Astronomy, University of Pennsylvania , Philadelphia, PA 19104, USACenter for Computational Astrophysics, Flatiron Institute , New York, NY 10010, USAThe shape and orientation of dark matter (DM) halos are sensitive to the microphysics of the DM particles, yet in many mass models, the symmetry axes of the Milky Way’s DM halo are often assumed to be aligned with the symmetry axes of the stellar disk. This is well motivated for the inner DM halo, but not for the outer halo. We use zoomed-in cosmological baryonic simulations from the Latte suite of FIRE-2 Milky Way–mass galaxies to explore the evolution of the DM halo’s orientation with radius and time, with or without a major merger with a Large Magellanic Cloud analog, and when varying the DM model. In three of the four cold DM halos we examine, the orientation of the halo minor axis diverges from the stellar disk vector by more than 20° beyond about 30 galactocentric kpc, reaching a maximum of 30°–90°, depending on the individual halo’s formation history. In identical simulations using a model of self-interacting DM with σ = 1 cm ^2 g ^−1 , the halo remains aligned with the stellar disk out to ∼200–400 kpc. Interactions with massive satellites ( M ≳ 4 × 10 ^10 M _⊙ at pericenter; M ≳ 3.3 × 10 ^10 M _⊙ at infall) affect the orientation of the halo significantly, aligning the halo’s major axis with the satellite galaxy from the disk to the virial radius. The relative orientation of the halo and disk beyond 30 kpc is a potential diagnostic of self-interacting DM, if the effects of massive satellites can be accounted for.https://doi.org/10.3847/1538-4357/acea79Dark matterGalaxiesComputational methodsDisk galaxiesMilky Way dark matter haloGalaxy dark matter halos |
| spellingShingle | Jay Baptista Robyn Sanderson Dan Huber Andrew Wetzel Omid Sameie Michael Boylan-Kolchin Jeremy Bailin Philip F. Hopkins Claude-André Faucher-Giguere Sukanya Chakrabarti Drona Vargya Nondh Panithanpaisal Arpit Arora Emily Cunningham Orientations of Dark Matter Halos in FIRE-2 Milky Way–mass Galaxies The Astrophysical Journal Dark matter Galaxies Computational methods Disk galaxies Milky Way dark matter halo Galaxy dark matter halos |
| title | Orientations of Dark Matter Halos in FIRE-2 Milky Way–mass Galaxies |
| title_full | Orientations of Dark Matter Halos in FIRE-2 Milky Way–mass Galaxies |
| title_fullStr | Orientations of Dark Matter Halos in FIRE-2 Milky Way–mass Galaxies |
| title_full_unstemmed | Orientations of Dark Matter Halos in FIRE-2 Milky Way–mass Galaxies |
| title_short | Orientations of Dark Matter Halos in FIRE-2 Milky Way–mass Galaxies |
| title_sort | orientations of dark matter halos in fire 2 milky way mass galaxies |
| topic | Dark matter Galaxies Computational methods Disk galaxies Milky Way dark matter halo Galaxy dark matter halos |
| url | https://doi.org/10.3847/1538-4357/acea79 |
| work_keys_str_mv | AT jaybaptista orientationsofdarkmatterhalosinfire2milkywaymassgalaxies AT robynsanderson orientationsofdarkmatterhalosinfire2milkywaymassgalaxies AT danhuber orientationsofdarkmatterhalosinfire2milkywaymassgalaxies AT andrewwetzel orientationsofdarkmatterhalosinfire2milkywaymassgalaxies AT omidsameie orientationsofdarkmatterhalosinfire2milkywaymassgalaxies AT michaelboylankolchin orientationsofdarkmatterhalosinfire2milkywaymassgalaxies AT jeremybailin orientationsofdarkmatterhalosinfire2milkywaymassgalaxies AT philipfhopkins orientationsofdarkmatterhalosinfire2milkywaymassgalaxies AT claudeandrefauchergiguere orientationsofdarkmatterhalosinfire2milkywaymassgalaxies AT sukanyachakrabarti orientationsofdarkmatterhalosinfire2milkywaymassgalaxies AT dronavargya orientationsofdarkmatterhalosinfire2milkywaymassgalaxies AT nondhpanithanpaisal orientationsofdarkmatterhalosinfire2milkywaymassgalaxies AT arpitarora orientationsofdarkmatterhalosinfire2milkywaymassgalaxies AT emilycunningham orientationsofdarkmatterhalosinfire2milkywaymassgalaxies |