Galaxy and Mass Assembly (GAMA): dust obscuration in galaxies and their recent star formation histories

Dinuka Wijesinghe, Andrew Hopkins, Robert Sharp, Madusha Gunawardhana, Sarah Brough, Elaine Sadler, Simon Driver, Ivan Baldry, Steven Bamford, J Liske, J Loveday, Peder Norberg, John Peacock, Cristina Popescu, R Tuffs, Jonathan Bland-Hawthorn, Ewan Cameron, Scott Croom, C Frenk, D HillDavid Jones, E van Kampen, L Kelvin, K Kuijken, Barry Madore, B Nichol, H Parkinson, Kevin Pimbblet, Matthew Prescott, A Robotham, M Seibert, E Simmat, W Sutherland, Edward Taylor, D Thomas

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    33 Citations (Scopus)

    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 HI?, [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 and 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 and Dopita obscuration curve with an Rv value of 4.5 gives the best agreement between the different SFR indicators. The 2200 ?? 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 languageEnglish
    Pages (from-to)2291 - 2301
    Number of pages11
    JournalMonthly Notices of the Royal Astronomical Society
    Volume410
    Issue number4
    DOIs
    Publication statusPublished - 2011

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