The location of the CA II ions in the beta Pictoris disk

Abstract

view Abstract Citations (55) References (12) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The Location of the CA II Ions in the Beta Pictoris Disk Hobbs, L. M. ; Lagrange-Henri, A. M. ; Ferlet, R. ; Vidal-Madjar, A. ; Welty, D. E. Abstract Echelle spectra of beta Pictoris have been obtained in the region of the Ca II 8542A line which arises from the metastable 3d 2D5/2 level. A narrow, weak, circumstellar absorption line is seen at the stellar radial velocity. A simple theory is developed of the radiative pumping of the metastable levels of the Ca II ions by the radiation from the star at the H and K lines. The relatively large fractional population, N3(Ca II)/N1(Ca II) of roughly 0.05, observed for the metastable level then requires that the calcium absorbers be largely concentrated within about 1 AU of the star. This result confirms two previous, independent estimates of the location of this gas. A time-variable circumstellar component of the 8542A line also is found at an infall velocity of about 15 km/s. Publication: The Astrophysical Journal Pub Date: November 1988 DOI: 10.1086/185308 Bibcode: 1988ApJ...334L..41H Keywords: Atomic Energy Levels; Calcium; Line Spectra; Stellar Envelopes; Absorption Spectra; Echelle Gratings; Interstellar Extinction; Parity; Radial Velocity; Astrophysics; LINE FORMATION; STARS: CIRCUMSTELLAR SHELLS full text sources ADS | data products SIMBAD (2)