Abstract
In this paper, we calculate new line lists and opacities for the 12 bands of the A(6)Sigma(+)-X(6)Sigma(+) transitions of the CrH molecule. Identified in objects of the new L dwarf spectroscopic class (many of which are brown dwarfs), as well as in sunspots, the CrH molecule plays an important role in the diagnosis of low-temperature atmospheres. As a tentative first application of these opacities, we employ our new theoretical CrH data in an atmospheres code to obtain a CrH/H-2 number ratio for the skin of the L5 dwarf 2MASSI J1507038-151648 of similar to(2-4) x 10(-9), in rough agreement with chemical equilibrium expectations. Since in previous compilations the oscillator strength was off by more than an order of magnitude, this agreement represents a modest advance. However, in order to fit the CrH abundance in the L dwarf spectral class, silicate clouds need to be incorporated into the model. Given that this subject is still in a primitive stage of development, one should view any spectral model in the L dwarf range as merely tentative. Nevertheless, a necessary first step in L dwarf modeling is a reliable CrH opacity algorithm, and this is what we have here attempted to provide.
| Original language | English |
|---|---|
| Pages (from-to) | 986-992 |
| Number of pages | 7 |
| Journal | The Astrophysical Journal |
| Volume | 577 |
| Issue number | 2 |
| DOIs | |
| Publication status | Published - 1 Oct 2002 |
Keywords
- astrochemistry
- infrared : stars
- molecular data
- stars : atmospheres
- stars : fundamental parameters
- stars : low-mass, brown dwarfs
- LASER MAGNETIC-RESONANCE
- STATE
- SPECTROSCOPY
- ABUNDANCES
- SPECTRA
- STARS
- BAND