Figure Rotation of IllustrisTNG Halos
We use the TNG50 and TNG50 dark matter (DM)-only simulations from the IllustrisTNG simulation suite to conduct an updated survey of halo figure rotation in the presence of baryons. We develop a novel methodology to detect coherent figure rotation about an arbitrary axis and for arbitrary durations,...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
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IOP Publishing
2023-01-01
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| Series: | The Astrophysical Journal |
| Subjects: | |
| Online Access: | https://doi.org/10.3847/1538-4357/acf30c |
| _version_ | 1797674735479291904 |
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| author | Neil Ash Monica Valluri |
| author_facet | Neil Ash Monica Valluri |
| author_sort | Neil Ash |
| collection | DOAJ |
| description | We use the TNG50 and TNG50 dark matter (DM)-only simulations from the IllustrisTNG simulation suite to conduct an updated survey of halo figure rotation in the presence of baryons. We develop a novel methodology to detect coherent figure rotation about an arbitrary axis and for arbitrary durations, and we apply it to a catalog of 1577 DM halos from the DM-only run and 1396 DM halos from the DM+baryons (DM+B) run that are free of major mergers. Figure rotation was detected in 94% of DM-only halos and 82% of the DM+B halos. The pattern speeds of rotations lasting ≳1 h ^−1 Gyr were log-normally distributed with medians of 0.25 h km s ^−1 kpc ^−1 for DM-only in agreement with past results, but 14% higher at 0.29 h km s ^−1 kpc ^−1 in the DM+B halos. We find that rotation axes are typically aligned with the halo minor or major axis in 57% of DM-only halos and in 62% of DM+B halos. The remaining rotation axes were not strongly aligned with any principal axis but typically lie in the plane containing the halo minor and major axes. Longer-lived rotations showed greater alignment with the halo minor axis in both simulations. Our results show that, in the presence of baryons, figure rotation is marginally less common, shorter-lived, faster, and better aligned with the minor axis than in DM-only halos. This updated understanding will be consequential for future efforts to constrain figure rotation in the Milky Way dark halo using the morphology and kinematics of tidal streams. |
| first_indexed | 2024-03-11T22:04:28Z |
| format | Article |
| id | doaj.art-0687965b96774c359943551b5541dfe1 |
| institution | Directory Open Access Journal |
| issn | 1538-4357 |
| language | English |
| last_indexed | 2024-03-11T22:04:28Z |
| publishDate | 2023-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | The Astrophysical Journal |
| spelling | doaj.art-0687965b96774c359943551b5541dfe12023-09-25T09:14:41ZengIOP PublishingThe Astrophysical Journal1538-43572023-01-01955211110.3847/1538-4357/acf30cFigure Rotation of IllustrisTNG HalosNeil Ash0https://orcid.org/0009-0003-7613-3109Monica Valluri1https://orcid.org/0000-0002-6257-2341University of Michigan Department of Astronomy 1085 S. University Ann Arbor, MI 48109, USAUniversity of Michigan Department of Astronomy 1085 S. University Ann Arbor, MI 48109, USAWe use the TNG50 and TNG50 dark matter (DM)-only simulations from the IllustrisTNG simulation suite to conduct an updated survey of halo figure rotation in the presence of baryons. We develop a novel methodology to detect coherent figure rotation about an arbitrary axis and for arbitrary durations, and we apply it to a catalog of 1577 DM halos from the DM-only run and 1396 DM halos from the DM+baryons (DM+B) run that are free of major mergers. Figure rotation was detected in 94% of DM-only halos and 82% of the DM+B halos. The pattern speeds of rotations lasting ≳1 h ^−1 Gyr were log-normally distributed with medians of 0.25 h km s ^−1 kpc ^−1 for DM-only in agreement with past results, but 14% higher at 0.29 h km s ^−1 kpc ^−1 in the DM+B halos. We find that rotation axes are typically aligned with the halo minor or major axis in 57% of DM-only halos and in 62% of DM+B halos. The remaining rotation axes were not strongly aligned with any principal axis but typically lie in the plane containing the halo minor and major axes. Longer-lived rotations showed greater alignment with the halo minor axis in both simulations. Our results show that, in the presence of baryons, figure rotation is marginally less common, shorter-lived, faster, and better aligned with the minor axis than in DM-only halos. This updated understanding will be consequential for future efforts to constrain figure rotation in the Milky Way dark halo using the morphology and kinematics of tidal streams.https://doi.org/10.3847/1538-4357/acf30cDark matter distributionGalaxy dark matter halosMilky Way dark matter haloGalaxy evolutionMilky Way evolution |
| spellingShingle | Neil Ash Monica Valluri Figure Rotation of IllustrisTNG Halos The Astrophysical Journal Dark matter distribution Galaxy dark matter halos Milky Way dark matter halo Galaxy evolution Milky Way evolution |
| title | Figure Rotation of IllustrisTNG Halos |
| title_full | Figure Rotation of IllustrisTNG Halos |
| title_fullStr | Figure Rotation of IllustrisTNG Halos |
| title_full_unstemmed | Figure Rotation of IllustrisTNG Halos |
| title_short | Figure Rotation of IllustrisTNG Halos |
| title_sort | figure rotation of illustristng halos |
| topic | Dark matter distribution Galaxy dark matter halos Milky Way dark matter halo Galaxy evolution Milky Way evolution |
| url | https://doi.org/10.3847/1538-4357/acf30c |
| work_keys_str_mv | AT neilash figurerotationofillustristnghalos AT monicavalluri figurerotationofillustristnghalos |