Laboratory Spectra of Astronomical Dust Analogs at Ultraviolet-Visible Wavelengths
Abstract
The absorption, scattering, and re-emission of light by dust grains in space affects the interpretation of stellar formation processes, galactic star formation rates, intrinsic spectral energy distributions of stars along given sightlines, and observed spectral signatures of a variety of astronomical object classes. Quantifying optical properties of dust grains (silicates, carbides, sulfides, oxides) is therefore highly necessary for such investigations. Whereas data at IR wavelengths can provide information on dust grain composition, spectral features should also be present and accounted for at visible-UV wavelengths. Several forms of laboratory data are needed to determine optical and spectroscopic properties of astronomical dust grains: (1) absorbance spectra, which can be converted to mass absorption coefficients for direct comparison to observational spectra, under the assumption that the grain sizes and shapes of the laboratory samples are similar to those dispersed in space, (2) reflectivity spectra, which may be used to derive (3) optical functions that are used as inputs for radiative transfer models and in analyzing the effect of grain morphologies on spectral features. However, astronomers do not have access to such laboratory data for many of the compounds believed to exist in space across the full electromagnetic spectrum, particularly at wavelengths below 2 μm. To address this need, we present a set of lab data at λ = 0.19-1.1 μm for astronomical dust proxies that may be used to better constrain dust models and interpret extinction curves from the ISM, PNe, and SNe.
- Publication:
-
American Astronomical Society Meeting Abstracts #215
- Pub Date:
- January 2010
- Bibcode:
- 2010AAS...21547603P