Computer Science – Numerical Analysis
Scientific paper
Feb 1995
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1995apj...439.1011f&link_type=abstract
The Astrophysical Journal, Part 1 (ISSN 0004-637X), vol. 439, no. 2, p. 1011-1020
Computer Science
Numerical Analysis
18
A Stars, Chromosphere, Emission Spectra, Lyman Alpha Radiation, Stellar Gravitation, Stellar Models, Stellar Temperature, Data Reduction, Numerical Analysis, Spectrum Analysis, X Ray Analysis
Scientific paper
The star, Altair (A7 IV-V), is clearly shown to have Lyman-alpha emission of chromospheric origin, while no evidence is found for the Mg II emission reported in previous investigations. We present non-Local Thermodymanic Equilibrium (non-LTE) semiempirical models incorporating partial redistribution of the chromosphere of Altair that reproduce the observed Lyman-alpha emission and the Mg II resonance absorption at 2800 A. We unambiguously establihed that chromospheres exist at spectral types as early as A7 on the main sequence, and we also demonstrate that it very unlikely that the observed emission originates in a corotating expanding wind. This result represents a new challenge for chromospheric heating theories. It may indicate that both differential rotation and convection layers, at least near the equator, exist in this fast rotating (v sin i = 220 km/s) star.
Bruhweiler Fred
Catalano Santo
Ferrero Rubens Freire
Gouttebroze Pierre
Kondo Yoshihiko
No associations
LandOfFree
Chromospheric models for ALTAIR (A7 IV-V) does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Chromospheric models for ALTAIR (A7 IV-V), we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Chromospheric models for ALTAIR (A7 IV-V) will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1630712