Self-Consistent Quiescent Model Atmospheres for M Dwarfs
Abstract
H alpha and Ca II K are two of the strongest emission lines in M dwarf chromospheres, responsible for
cooling the atmosphere, balancing the magnetic heating, and determining the resulting equilibrium structure. To investigate the relationship between these two important lines, I captured simultaneous observations of Ca II K and H alpha for 85 dM3 stars of varying activity strength. The results of my observing program reveal a complex relationship between the two, where even so-called "inactive" stars (those with H alpha in absorption) may display substantial Ca II K emission. A new generation of quiescent model atmospheres is required to further investigate the chromospheric heating required to produce both of these lines at the observed levels. I present the observed results, and discuss their application as empirical constraints on static models of quiescent M dwarf atmospheres. I also present initial model calculations and place them in the context of the data.- Publication:
-
American Astronomical Society Meeting Abstracts
- Pub Date:
- December 2007
- Bibcode:
- 2007AAS...211.2105W