Collisional line profiles of rubidium and cesium perturbed by helium and molecular hydrogen

Previous calculations of the far wings of the potassium and sodium doublets in a unified-line shape semi-classical theory have been used recently to improve theoretical modeling of synthetic spectra of brown dwarfs. However the comparison with observations shows missing opacity in the 0.85 to 1.1  μ m range. Contributions of other alkalis such as Rb I and Cs I may resolve this problem. We present new theoretical calculations of the line profiles of these two alkalis perturbed by helium and molecular hydrogen.

[1]  M. Baranger.  SIMPLIFIED QUANTUM-MECHANICAL THEORY OF PRESSURE BROADENING , 1958 .

[2]  F. Allard,et al.  Theoretical profiles of light alkali resonance lines for brown dwarf atmosphere conditions , 2005 .

[3]  J. Kielkopf,et al.  Observation of the Simultaneous Additive Effect of Several Xenon Perturbers on the Cs6s−9pDoublet , 1979 .

[4]  J. Pascale.  Use of l-dependent pseudopotentials in the study of alkali-metal-atom--He systems. The adiabatic molecular potentials , 1983 .

[5]  F. Allard,et al.  A new model for brown dwarf spectra including accurate unified line shape theory for the Na I and K I resonance line profiles , 2003 .

[6]  A. Burrows,et al.  Calculations of the Far-Wing Line Profiles of Sodium and Potassium in the Atmospheres of Substellar-Mass Objects , 2002, astro-ph/0210086.

[7]  M. Baranger.  Problem of Overlapping Lines in the Theory of Pressure Broadening , 1958 .

[8]  W. R. Hindmarsh,et al.  Collision broadening and satellite bands in the potassium line 4047 Angstrom perturbed by krypton , 1969 .

[9]  B. Schneider,et al.  Ground and excited states of Ne2 and Ne2+. I. Potential curves with and without spin‐orbit coupling , 1974 .

[10]  W. E. Baylis,et al.  Profiles of line wings and rainbow satellites associated with optical and radiative collisions , 1996 .

[11]  John F. Kielkopf,et al.  Effect of the variation of electric-dipole moments on the shape of pressure-broadened atomic spectral lines , 1999 .

[12]  W. E. Baylis,et al.  Unified Franck-Condon treatment of pressure broadening of spectral lines , 1975 .

[13]  Alkali-rare-gas line profiles in a square-well potential approximation. I. Satellites , 1978 .

[14]  Rossi,et al.  Pseudopotential molecular-structure calculations for alkali-metal-atom-H2 systems. , 1985, Physical review. A, General physics.

[15]  Shang-yi Ch'en,et al.  Pressure Effects of Foreign Gases on the Absorption Lines of Cesium. VI. Intensity Measurements of the Cesium Resonance Lines and Their Associated Satellites in the Presence of Various Foreign Gases , 1969 .

[16]  John F. Kielkopf,et al.  The effect of neutral nonresonant collisions on atomic spectral lines , 1982 .

[17]  A. Royer.  Shift, width, and asymmetry of pressure-broadened spectral lines at intermediate densities , 1980 .

[18]  David R. Alexander,et al.  THE LIMITING EFFECTS OF DUST IN BROWN DWARF MODEL ATMOSPHERES , 2001 .

[19]  Adam Burrows,et al.  The Near-Infrared and Optical Spectra of Methane Dwarfs and Brown Dwarfs , 1999, astro-ph/9908078.