Thermal-instability-driven Turbulent Mixing in Galactic Disks. I. Effective Mixing of Metals
(2012) In The Astrophysical Journal 758(1).- Abstract
- Observations show that radial metallicity gradients in disk galaxies are relatively shallow, if not flat, especially at large galactocentric distances and for galaxies in the high-redshift universe. Given that star formation and metal production are centrally concentrated, this requires a mechanism to redistribute metals. However, the nature of this mechanism is poorly understood, let alone quantified. To address this problem, we conduct magnetohydrodynamical simulations of a local shearing sheet of a thin, thermally unstable, gaseous disk driven by a background stellar spiral potential, including metals modeled as passive scalar fields. Contrary to what a simple α prescription for the gas disk would suggest, we find that turbulence driven... (More)
- Observations show that radial metallicity gradients in disk galaxies are relatively shallow, if not flat, especially at large galactocentric distances and for galaxies in the high-redshift universe. Given that star formation and metal production are centrally concentrated, this requires a mechanism to redistribute metals. However, the nature of this mechanism is poorly understood, let alone quantified. To address this problem, we conduct magnetohydrodynamical simulations of a local shearing sheet of a thin, thermally unstable, gaseous disk driven by a background stellar spiral potential, including metals modeled as passive scalar fields. Contrary to what a simple α prescription for the gas disk would suggest, we find that turbulence driven by thermal instability is very efficient at mixing metals, regardless of the presence or absence of stellar spiral potentials or magnetic fields. The timescale for homogenizing randomly distributed metals is comparable to or less than the local orbital time in the disk. This implies that turbulent mixing of metals is a significant process in the history of chemical evolution of disk galaxies. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/4361506
- author
- Yang, Chao-Chin LU and Krumholz, Mark
- publishing date
- 2012
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- galaxies: abundances galaxies: ISM galaxies: kinematics and dynamics instabilities methods: numerical turbulence
- in
- The Astrophysical Journal
- volume
- 758
- issue
- 1
- article number
- 48
- publisher
- American Astronomical Society
- external identifiers
-
- scopus:84866897492
- DOI
- 10.1088/0004-637X/758/1/48
- language
- English
- LU publication?
- no
- id
- 26974101-f7e6-49cc-87f0-f1211e42a536 (old id 4361506)
- date added to LUP
- 2016-04-04 11:11:21
- date last changed
- 2025-04-04 15:16:53
@article{26974101-f7e6-49cc-87f0-f1211e42a536,
abstract = {{Observations show that radial metallicity gradients in disk galaxies are relatively shallow, if not flat, especially at large galactocentric distances and for galaxies in the high-redshift universe. Given that star formation and metal production are centrally concentrated, this requires a mechanism to redistribute metals. However, the nature of this mechanism is poorly understood, let alone quantified. To address this problem, we conduct magnetohydrodynamical simulations of a local shearing sheet of a thin, thermally unstable, gaseous disk driven by a background stellar spiral potential, including metals modeled as passive scalar fields. Contrary to what a simple α prescription for the gas disk would suggest, we find that turbulence driven by thermal instability is very efficient at mixing metals, regardless of the presence or absence of stellar spiral potentials or magnetic fields. The timescale for homogenizing randomly distributed metals is comparable to or less than the local orbital time in the disk. This implies that turbulent mixing of metals is a significant process in the history of chemical evolution of disk galaxies.}},
author = {{Yang, Chao-Chin and Krumholz, Mark}},
keywords = {{galaxies: abundances galaxies: ISM galaxies: kinematics and dynamics instabilities methods: numerical turbulence}},
language = {{eng}},
number = {{1}},
publisher = {{American Astronomical Society}},
series = {{The Astrophysical Journal}},
title = {{Thermal-instability-driven Turbulent Mixing in Galactic Disks. I. Effective Mixing of Metals}},
url = {{http://dx.doi.org/10.1088/0004-637X/758/1/48}},
doi = {{10.1088/0004-637X/758/1/48}},
volume = {{758}},
year = {{2012}},
}