Which physics determines the location of the mean molecular weight minimum in red giants?
(2014) In Monthly Notices of the Royal Astronomical Society 443(2). p.977-984- Abstract
- Stars ascending the red giant branch develop an inversion in mean molecular weight (mu) owing to the burning of He-3 in the region immediately above their hydrogen-burning shells. This inversion may drive thermohaline mixing and thereby be responsible for the extra mixing which is observationally indicated on the red giant branch. In this paper, we investigate the physical influences that determine the mass and temperature at which the inversion in mu develops. We find that it depends most strongly on the thermal structure of the envelope - the profiles of density and temperature in the region of the star immediately above the shell - and is otherwise relatively insensitive to abundances and nuclear reaction rates. The changes in the... (More)
- Stars ascending the red giant branch develop an inversion in mean molecular weight (mu) owing to the burning of He-3 in the region immediately above their hydrogen-burning shells. This inversion may drive thermohaline mixing and thereby be responsible for the extra mixing which is observationally indicated on the red giant branch. In this paper, we investigate the physical influences that determine the mass and temperature at which the inversion in mu develops. We find that it depends most strongly on the thermal structure of the envelope - the profiles of density and temperature in the region of the star immediately above the shell - and is otherwise relatively insensitive to abundances and nuclear reaction rates. The changes in the effects of thermohaline mixing as stars proceed up the giant branch can mostly be understood in terms of their changing thermal structure, driven by their increasing core mass. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/4656193
- author
- Church, Ross
LU
; Lattanzio, John ; Angelou, George ; Tout, Christopher A. and Stancliffe, Richard J.
- organization
- publishing date
- 2014
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- methods: numerical, stars: abundances, stars: evolution
- in
- Monthly Notices of the Royal Astronomical Society
- volume
- 443
- issue
- 2
- pages
- 977 - 984
- publisher
- Oxford University Press
- external identifiers
-
- wos:000340436800004
- scopus:84905672851
- ISSN
- 1365-2966
- DOI
- 10.1093/mnras/stu1195
- language
- English
- LU publication?
- yes
- id
- be08fe0e-bb95-4474-8e94-818cc3f618f0 (old id 4656193)
- date added to LUP
- 2016-04-01 10:52:28
- date last changed
- 2024-01-07 03:19:22
@article{be08fe0e-bb95-4474-8e94-818cc3f618f0, abstract = {{Stars ascending the red giant branch develop an inversion in mean molecular weight (mu) owing to the burning of He-3 in the region immediately above their hydrogen-burning shells. This inversion may drive thermohaline mixing and thereby be responsible for the extra mixing which is observationally indicated on the red giant branch. In this paper, we investigate the physical influences that determine the mass and temperature at which the inversion in mu develops. We find that it depends most strongly on the thermal structure of the envelope - the profiles of density and temperature in the region of the star immediately above the shell - and is otherwise relatively insensitive to abundances and nuclear reaction rates. The changes in the effects of thermohaline mixing as stars proceed up the giant branch can mostly be understood in terms of their changing thermal structure, driven by their increasing core mass.}}, author = {{Church, Ross and Lattanzio, John and Angelou, George and Tout, Christopher A. and Stancliffe, Richard J.}}, issn = {{1365-2966}}, keywords = {{methods: numerical; stars: abundances; stars: evolution}}, language = {{eng}}, number = {{2}}, pages = {{977--984}}, publisher = {{Oxford University Press}}, series = {{Monthly Notices of the Royal Astronomical Society}}, title = {{Which physics determines the location of the mean molecular weight minimum in red giants?}}, url = {{http://dx.doi.org/10.1093/mnras/stu1195}}, doi = {{10.1093/mnras/stu1195}}, volume = {{443}}, year = {{2014}}, }