On the Significance of the Thick Disks of Disk Galaxies
Thick disks are a prevalent feature observed in numerous disk galaxies, including our own Milky Way. Their significance has been reported to vary widely, ranging from a few percent to 100% of the disk mass, depending on the galaxy and the measurement method. We use the NewHorizon simulation, which h...
| Main Authors: | , , , , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
IOP Publishing
2024-01-01
|
| Series: | The Astrophysical Journal Supplement Series |
| Subjects: | |
| Online Access: | https://doi.org/10.3847/1538-4365/ad0e71 |
| _version_ | 1797316399512682496 |
|---|---|
| author | Sukyoung K. Yi J. K. Jang Julien Devriendt Yohan Dubois San Han Taysun Kimm Katarina Kraljic Minjung Park Sebastien Peirani Christophe Pichon Jinsu Rhee |
| author_facet | Sukyoung K. Yi J. K. Jang Julien Devriendt Yohan Dubois San Han Taysun Kimm Katarina Kraljic Minjung Park Sebastien Peirani Christophe Pichon Jinsu Rhee |
| author_sort | Sukyoung K. Yi |
| collection | DOAJ |
| description | Thick disks are a prevalent feature observed in numerous disk galaxies, including our own Milky Way. Their significance has been reported to vary widely, ranging from a few percent to 100% of the disk mass, depending on the galaxy and the measurement method. We use the NewHorizon simulation, which has high spatial and stellar mass resolutions, to investigate the issue of the thick-disk mass fraction. We also use the NewHorizon2 simulation, which was run on the same initial conditions, but additionally traced nine chemical elements. Based on a sample of 27 massive disk galaxies with M _* > 10 ^10 M _⊙ in NewHorizon, the contribution of the thick disk was found to be 20% ± 11% in r -band luminosity or 35% ± 15% in mass to the overall galactic disk, which seems in agreement with observational data. The vertical profiles of 0, 22, and 5 galaxies are best fitted by 1, 2, or 3 ${{\rm{sech}} }^{2}$ components, respectively. The NewHorizon2 data show that the selection of thick-disk stars based on a single [ α /Fe] cut is contaminated by stars of different kinematic properties, while missing the bulk of kinematically thick disk stars. Vertical luminosity profile fits recover the key properties of thick disks reasonably well. The majority of stars are born near the galactic midplane with high circularity and get heated with time via fluctuations in the force field. Depending on the star formation and merger histories, galaxies may naturally develop thick disks with significantly different properties. |
| first_indexed | 2024-03-08T03:17:50Z |
| format | Article |
| id | doaj.art-956967faba0649f3b5cf292ecceb5a7e |
| institution | Directory Open Access Journal |
| issn | 0067-0049 |
| language | English |
| last_indexed | 2024-03-08T03:17:50Z |
| publishDate | 2024-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | The Astrophysical Journal Supplement Series |
| spelling | doaj.art-956967faba0649f3b5cf292ecceb5a7e2024-02-12T14:46:47ZengIOP PublishingThe Astrophysical Journal Supplement Series0067-00492024-01-012711110.3847/1538-4365/ad0e71On the Significance of the Thick Disks of Disk GalaxiesSukyoung K. Yi0https://orcid.org/0000-0002-4556-2619J. K. Jang1https://orcid.org/0000-0002-0858-5264Julien Devriendt2https://orcid.org/0000-0002-8140-0422Yohan Dubois3https://orcid.org/0000-0003-0225-6387San Han4https://orcid.org/0000-0001-9939-713XTaysun Kimm5https://orcid.org/0000-0002-3950-3997Katarina Kraljic6https://orcid.org/0000-0001-6180-0245Minjung Park7https://orcid.org/0000-0002-8435-9402Sebastien Peirani8Christophe Pichon9https://orcid.org/0000-0003-0695-6735Jinsu Rhee10https://orcid.org/0000-0002-0184-9589Department of Astronomy and Yonsei University Observatory, Yonsei University , Seoul 03722, Republic of Korea ; starbrown816@yonsei.ac.krDepartment of Astronomy and Yonsei University Observatory, Yonsei University , Seoul 03722, Republic of Korea ; starbrown816@yonsei.ac.krDepartment of Physics, University of Oxford , Keble Road, Oxford, OX1 3RH, UKInstitut d’Astrophysique de Paris, Sorbonne Université , CNRS, UMR 7095, 98 bis bd Arago, F-75014 Paris, FranceDepartment of Astronomy and Yonsei University Observatory, Yonsei University , Seoul 03722, Republic of Korea ; starbrown816@yonsei.ac.krDepartment of Astronomy and Yonsei University Observatory, Yonsei University , Seoul 03722, Republic of Korea ; starbrown816@yonsei.ac.krUniversité de Strasbourg , CNRS, Observatoire astronomique de Strasbourg, UMR 7550, F-67000 Strasbourg, FranceCenter for Astrophysics ∣ Harvard & Smithsonian , 60 Garden Street, Cambridge, MA 02138, USAInstitut d’Astrophysique de Paris, Sorbonne Université , CNRS, UMR 7095, 98 bis bd Arago, F-75014 Paris, France; Observatoire de la Côte d’Azur, CNRS, Laboratoire Lagrange, Bd de l’Observatoire, Université Côte d’Azur , CS 34229, F-06304 Nice Cedex 4, FranceInstitut d’Astrophysique de Paris, Sorbonne Université , CNRS, UMR 7095, 98 bis bd Arago, F-75014 Paris, FranceDepartment of Astronomy and Yonsei University Observatory, Yonsei University , Seoul 03722, Republic of Korea ; starbrown816@yonsei.ac.kr; Korea Astronomy and Space Science Institute , 776, Daedeokdae-ro, Yuseong-gu, Daejeon 34055, Republic of KoreaThick disks are a prevalent feature observed in numerous disk galaxies, including our own Milky Way. Their significance has been reported to vary widely, ranging from a few percent to 100% of the disk mass, depending on the galaxy and the measurement method. We use the NewHorizon simulation, which has high spatial and stellar mass resolutions, to investigate the issue of the thick-disk mass fraction. We also use the NewHorizon2 simulation, which was run on the same initial conditions, but additionally traced nine chemical elements. Based on a sample of 27 massive disk galaxies with M _* > 10 ^10 M _⊙ in NewHorizon, the contribution of the thick disk was found to be 20% ± 11% in r -band luminosity or 35% ± 15% in mass to the overall galactic disk, which seems in agreement with observational data. The vertical profiles of 0, 22, and 5 galaxies are best fitted by 1, 2, or 3 ${{\rm{sech}} }^{2}$ components, respectively. The NewHorizon2 data show that the selection of thick-disk stars based on a single [ α /Fe] cut is contaminated by stars of different kinematic properties, while missing the bulk of kinematically thick disk stars. Vertical luminosity profile fits recover the key properties of thick disks reasonably well. The majority of stars are born near the galactic midplane with high circularity and get heated with time via fluctuations in the force field. Depending on the star formation and merger histories, galaxies may naturally develop thick disks with significantly different properties.https://doi.org/10.3847/1538-4365/ad0e71Galaxy disksGalaxy stellar disksGalaxy structureGalaxy chemical evolutionHydrodynamical simulations |
| spellingShingle | Sukyoung K. Yi J. K. Jang Julien Devriendt Yohan Dubois San Han Taysun Kimm Katarina Kraljic Minjung Park Sebastien Peirani Christophe Pichon Jinsu Rhee On the Significance of the Thick Disks of Disk Galaxies The Astrophysical Journal Supplement Series Galaxy disks Galaxy stellar disks Galaxy structure Galaxy chemical evolution Hydrodynamical simulations |
| title | On the Significance of the Thick Disks of Disk Galaxies |
| title_full | On the Significance of the Thick Disks of Disk Galaxies |
| title_fullStr | On the Significance of the Thick Disks of Disk Galaxies |
| title_full_unstemmed | On the Significance of the Thick Disks of Disk Galaxies |
| title_short | On the Significance of the Thick Disks of Disk Galaxies |
| title_sort | on the significance of the thick disks of disk galaxies |
| topic | Galaxy disks Galaxy stellar disks Galaxy structure Galaxy chemical evolution Hydrodynamical simulations |
| url | https://doi.org/10.3847/1538-4365/ad0e71 |
| work_keys_str_mv | AT sukyoungkyi onthesignificanceofthethickdisksofdiskgalaxies AT jkjang onthesignificanceofthethickdisksofdiskgalaxies AT juliendevriendt onthesignificanceofthethickdisksofdiskgalaxies AT yohandubois onthesignificanceofthethickdisksofdiskgalaxies AT sanhan onthesignificanceofthethickdisksofdiskgalaxies AT taysunkimm onthesignificanceofthethickdisksofdiskgalaxies AT katarinakraljic onthesignificanceofthethickdisksofdiskgalaxies AT minjungpark onthesignificanceofthethickdisksofdiskgalaxies AT sebastienpeirani onthesignificanceofthethickdisksofdiskgalaxies AT christophepichon onthesignificanceofthethickdisksofdiskgalaxies AT jinsurhee onthesignificanceofthethickdisksofdiskgalaxies |