Analysis of the Intrinsic βλ,0 Ratio using Spectral Synthesis Models of Composite Stellar Populations
Abstract
Light from galaxies is extincted by dust via scattering and absorbtion. Studying galaxies without correcting for this extinction could lead to incorrect results. Therefore, a careful study of dust correction in the nearby universe should be done first. Tamura et al. (2009) developed an approximate method, dubbed the "βV" method, which corrects for dust extinction on a pixel by pixel basis by comparing the observed and the intrinsic flux ratios of optical and MIR (L~3.5μm) broadband data. A NASA/ADAP funded program "Magellanic Clues to Spatially-resolved Extinction Corrections for Distant Galaxies in the HST/JWST Era" (P.I. : Rolf Jansen), aims to validate and test the limits of the "βV" method by using imagery of the LMC and SMC in various filters and extensive modeling to test assumptions for the intrinsic flux ratios. For the latter, we build spectral energy distribution (SED) models of simple stellar population (SSP), by adopting Starburst99 and BC03 models for young (<9Myr) and old (>100Myr) stellar populations, respectively, and linear combinations of these for intermediate ages. We then construct composite stellar population (CSP) SEDs by combining SSP SEDs as functions of various star formation histories (SFHs). Filter response/throughput curves (V,I,WISE W1(3.4μm), Spitzer IRAC-1 (3.6μm) and L-band) were convolved with the model SEDs to obtain the intrinsic flux ratios (βλ,0). We present the values of βλ,0 as a function of the age and metallicity of stellar populations, and discuss the effect of various SFHs. We also present ranges of βλ,0 values for different types of galaxies.
- Publication:
-
American Astronomical Society Meeting Abstracts #225
- Pub Date:
- January 2015
- Bibcode:
- 2015AAS...22514314K