How does the shape of the stellar spectrum affect the Raman scattering features in the albedo of exoplanets?
arXiv:1708.04243 · doi:10.3847/1538-4357/aa8630
Abstract
Diagnostic potential of the spectral signatures of Raman scattering imprinted in planetary albedo spectra at short optical wavelengths has been demonstrated in research on Solar System planets and has recently been proposed as a probe of exoplanet atmospheres, complementary to albedo studies at longer wavelengths. Spectral features caused by Raman scattering offer insight into the properties of planetary atmospheres, such as the atmospheric depth, composition, and temperature, as well as the possibility of detecting and spectroscopically identifying spectrally inactive species, such as H and N, in the visible wavelength range. Raman albedo features, however, depend on both the properties of the atmosphere and the shape of the incident stellar spectrum. Identical planetary atmospheres can produce very different albedo spectra depending on the spectral properties of the host star. Here we present a set of geometric albedo spectra calculated for atmospheres with H/He, N, and CO composition, irradiated by different stellar types ranging from late A to late K stars. Prominent albedo features caused by Raman scattering appear at different wavelengths for different types of host stars. We investigate how absorption due to alkali elements, sodium and potassium, may affect the intensity of Raman features, and discuss the preferred observing strategies for detecting Raman features in future observations.
12 pages; accepted for publication in ApJ
References in corpus (15)
- Contributions to the Nearby Stars (NStars) Project: Spectroscopy of Stars Earlier than M0 within 40 parsecs: The Southern Sample
- Atomic and Molecular Opacities for Brown Dwarf and Giant Planet Atmospheres
- The Very Low Albedo of an Extrasolar Planet: MOST Spacebased Photometry of HD 209458
- Spectropolarimetric signatures of Earth-like extrasolar planets
- Discovery of water at high spectral resolution in the atmosphere of 51 Peg b
- Optical Albedo Theory of Strongly-Irradiated Giant Planets: The Case of HD 209458b
- Analytical Models of Exoplanetary Atmospheres. II. Radiative Transfer via the Two-stream Approximation
- Evidence for a spectroscopic direct detection of reflected light from 51 Peg b
- Clouds on the hot Jupiter HD189733b: constraints from the reflection spectrum
- Sulfur Hazes in Giant Exoplanet Atmospheres: Impacts on Reflected Light Spectra
- A grid of polarization models for Rayleigh scattering planetary atmospheres
- The Albedos of Kepler's Close-in super-Earths
- Atmospheric Retrieval for Direct Imaging Spectroscopy of Gas Giants In Reflected Light II: Orbital Phase and Planetary Radius
- Accurate and Approximate Calculations of Raman Scattering in the Atmosphere of Neptune
- The influence of non-isotropic scattering of thermal radiation on spectra of brown dwarfs and hot exoplanets