Two micron CO absorption lines in the spectrum of Epsilon Aurigae during eclipse

Abstract

view Abstract Citations (18) References (30) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Two Micron CO Absorption Lines in the Spectrum of Epsilon Aurigae during Eclipse Hinkle, Kenneth H. ; Simon, Theodore Abstract CO Delta-v = 2 absorption lines have been detected in the infrared eclipse spectrum of Epsilon Aur. These lines arise within a gas torus associated with the 'unseen' companion to the F Ia star. The torus is asymmetric about its center, having a CO column density at least a factor of 80 larger on its trailing edge than on its leading edge. The CO excitation temperature on the trailing edge is 1000 + or - 150 K. The largest column density observed along a line of sight through the torus to the primary is 3 x 10 to the 20th CO/sq cm. Accurate CO velocity measurements were made at third and fourth contact. Assuming that the gas follows Keplerian motion around the secondary star(s), the velocities imply M1 less than about 7 solar mass and M2 less than about 10 solar mass. These limits favor a low-mass, post-asymptotic giant branch interpretation of the F0 Ia component. (C-12)/(C-13) = 10 + or - 3 in the gas torus, indicating that the gas has been accreted from the primary. The accretion of material from the primary suggests that the UV continuum detected at wavelengths below 1400 A arises in a warm boundary layer of an accretion disk surrounding the central star(s) of the secondary. Publication: The Astrophysical Journal Pub Date: April 1987 DOI: 10.1086/165134 Bibcode: 1987ApJ...315..296H Keywords: Absorption Spectra; Accretion Disks; Carbon Monoxide; Eclipsing Binary Stars; Infrared Spectra; Stellar Spectra; Abundance; Asymptotic Giant Branch Stars; Companion Stars; Stellar Mass; Stellar Mass Accretion; Astrophysics full text sources ADS | data products SIMBAD (1)