Abstract
We present self-consistent star formation rates derived through pan-spectral analysis of galaxies drawn from the Galaxy and Mass Assembly (GAMA) survey. We determine the most appropriate form of dust obscuration correction via application of a range of extinction laws drawn from the literature as applied to H alpha, [O II] and UV luminosities. These corrections are applied to a sample of 31 508 galaxies from the GAMA survey at z < 0.35. We consider several different obscuration curves, including those of Milky Way, Calzetti and Fischera & Dopita curves and their effects on the observed luminosities. At the core of this technique is the observed Balmer decrement, and we provide a prescription to apply optimal obscuration corrections using the Balmer decrement. We carry out an analysis of the star formation history (SFH) using stellar population synthesis tools to investigate the evolutionary history of our sample of galaxies as well as to understand the effects of variation in the initial mass function (IMF) and the effects this has on the evolutionary history of galaxies. We find that the Fischera & Dopita obscuration curve with an R-v value of 4.5 gives the best agreement between the different SFR indicators. The 2200 angstrom feature needed to be removed from this curve to obtain complete consistency between all SFR indicators suggesting that this feature may not be common in the average integrated attenuation of galaxy emission. We also find that the UV dust obscuration is strongly dependent on the SFR.
Original language | English |
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Pages (from-to) | 2291-2301 |
Number of pages | 11 |
Journal | Monthly Notices of the Royal Astronomical Society |
Volume | 410 |
Issue number | 4 |
DOIs | |
Publication status | Published - Feb 2011 |
Keywords
- galaxies: evolution
- galaxies: formation
- galaxies: fundamental parameters
- galaxies: general
- galaxies: luminosity function, mass function
- SPECTRAL ENERGY-DISTRIBUTION
- SMALL MAGELLANIC CLOUD
- DIGITAL SKY SURVEY
- FORMATION RATES
- STARBURST GALAXIES
- SPIRAL GALAXIES
- H-ALPHA
- INTERSTELLAR EXTINCTION
- ULTRAVIOLET EXTINCTION
- COMPACT GALAXIES