Vertical Shear Instability in Thermally Stratified Protoplanetary Disks. II. Hydrodynamic Simulations and Observability
We conduct 3D hydrodynamic simulations to investigate the nonlinear outcomes and observability of vertical shear instability (VSI) in protoplanetary disks. Our models include both vertically isothermal and thermally stratified disks, with the latter representing realistic conditions featuring a hott...
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IOP Publishing
2025-01-01
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| Series: | The Astrophysical Journal |
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| Online Access: | https://doi.org/10.3847/1538-4357/ad9f42 |
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| author | Han-Gyeol Yun Woong-Tae Kim Jaehan Bae Cheongho Han |
| author_facet | Han-Gyeol Yun Woong-Tae Kim Jaehan Bae Cheongho Han |
| author_sort | Han-Gyeol Yun |
| collection | DOAJ |
| description | We conduct 3D hydrodynamic simulations to investigate the nonlinear outcomes and observability of vertical shear instability (VSI) in protoplanetary disks. Our models include both vertically isothermal and thermally stratified disks, with the latter representing realistic conditions featuring a hotter atmosphere above the midplane. We find that the VSI grows more rapidly and becomes stronger in thermally stratified disks due to enhanced shear, resulting in higher levels of turbulence. At saturation, the turbulence stress reaches α _Rϕ ≳ 10 ^−3 , more than 1 order of magnitude stronger than the isothermal case. The saturated turbulence is more pronounced near the disk surfaces than at the midplane. On synthetic velocity residual maps, obtained by subtracting the Keplerian rotational velocity, perturbations driven by the VSI manifest as axisymmetric rings in isothermal disks and as ring segments in thermally stratified disks. The latter are visible at disk inclinations as high as 45° in thermally stratified disks. The amplitudes of these residual velocities range from ∼50 to ∼100 m s ^−1 at a 20° inclination, with larger values corresponding to greater thermal stratification. The magnitude of the observed velocity residual increases with the optical depth of the tracer used, as optically thick lines probe the regions near the disk surfaces. |
| format | Article |
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| institution | Kabale University |
| issn | 1538-4357 |
| language | English |
| publishDate | 2025-01-01 |
| publisher | IOP Publishing |
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| series | The Astrophysical Journal |
| spelling | doaj-art-4fe6d02eda7d4044b87aa65766983a562025-01-31T07:41:08ZengIOP PublishingThe Astrophysical Journal1538-43572025-01-0198011510.3847/1538-4357/ad9f42Vertical Shear Instability in Thermally Stratified Protoplanetary Disks. II. Hydrodynamic Simulations and ObservabilityHan-Gyeol Yun0https://orcid.org/0000-0003-4353-294XWoong-Tae Kim1https://orcid.org/0000-0003-4625-229XJaehan Bae2https://orcid.org/0000-0001-7258-770XCheongho Han3https://orcid.org/0000-0002-2641-9964Department of Physics & Astronomy, Seoul National University , Seoul 08826, Republic of Korea ; hangyeol@snu.ac.kr, wkim@astro.snu.ac.kr; SNU Astronomy Research Center, Seoul National University , 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of KoreaDepartment of Physics & Astronomy, Seoul National University , Seoul 08826, Republic of Korea ; hangyeol@snu.ac.kr, wkim@astro.snu.ac.kr; SNU Astronomy Research Center, Seoul National University , 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of KoreaDepartment of Astronomy, University of Florida , Gainesville, FL 32611, USA ; jbae@ufl.eduDepartment of Physics, Chungbuk National University , Cheongju 28644, Republic of Korea ; cheongho@astroph.chungbuk.ac.krWe conduct 3D hydrodynamic simulations to investigate the nonlinear outcomes and observability of vertical shear instability (VSI) in protoplanetary disks. Our models include both vertically isothermal and thermally stratified disks, with the latter representing realistic conditions featuring a hotter atmosphere above the midplane. We find that the VSI grows more rapidly and becomes stronger in thermally stratified disks due to enhanced shear, resulting in higher levels of turbulence. At saturation, the turbulence stress reaches α _Rϕ ≳ 10 ^−3 , more than 1 order of magnitude stronger than the isothermal case. The saturated turbulence is more pronounced near the disk surfaces than at the midplane. On synthetic velocity residual maps, obtained by subtracting the Keplerian rotational velocity, perturbations driven by the VSI manifest as axisymmetric rings in isothermal disks and as ring segments in thermally stratified disks. The latter are visible at disk inclinations as high as 45° in thermally stratified disks. The amplitudes of these residual velocities range from ∼50 to ∼100 m s ^−1 at a 20° inclination, with larger values corresponding to greater thermal stratification. The magnitude of the observed velocity residual increases with the optical depth of the tracer used, as optically thick lines probe the regions near the disk surfaces.https://doi.org/10.3847/1538-4357/ad9f42Protoplanetary disksHydrodynamicsHydrodynamical simulationsRadiative transferAccretion |
| spellingShingle | Han-Gyeol Yun Woong-Tae Kim Jaehan Bae Cheongho Han Vertical Shear Instability in Thermally Stratified Protoplanetary Disks. II. Hydrodynamic Simulations and Observability The Astrophysical Journal Protoplanetary disks Hydrodynamics Hydrodynamical simulations Radiative transfer Accretion |
| title | Vertical Shear Instability in Thermally Stratified Protoplanetary Disks. II. Hydrodynamic Simulations and Observability |
| title_full | Vertical Shear Instability in Thermally Stratified Protoplanetary Disks. II. Hydrodynamic Simulations and Observability |
| title_fullStr | Vertical Shear Instability in Thermally Stratified Protoplanetary Disks. II. Hydrodynamic Simulations and Observability |
| title_full_unstemmed | Vertical Shear Instability in Thermally Stratified Protoplanetary Disks. II. Hydrodynamic Simulations and Observability |
| title_short | Vertical Shear Instability in Thermally Stratified Protoplanetary Disks. II. Hydrodynamic Simulations and Observability |
| title_sort | vertical shear instability in thermally stratified protoplanetary disks ii hydrodynamic simulations and observability |
| topic | Protoplanetary disks Hydrodynamics Hydrodynamical simulations Radiative transfer Accretion |
| url | https://doi.org/10.3847/1538-4357/ad9f42 |
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