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arXiv · 1110.0726

Extinction in Nebular Luminosities & Star Formation Rate of Disk Galaxies: Inclination Correction

Ching-Wa Yip·Alex S. Szalay
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Abstract

Star formation is one of the most important processes in galaxy formation. The luminosity of Halpha recombination and [OII] forbidden emissions remain to be most used in measuring formation rate of massive stars in galaxies. Here we report the inclination dependency of continuum-subtracted and aperture-corrected nebular luminosities, including Halpha, Hbeta, Hgamma, [OII], [NII], of disk-dominated galaxies in the local universe. Their luminosities decrease by a factor of three from face-on to edge-on (axis ratio limit = 0.17) orientations. This dependence is deduced to be caused by extinction due to diffuse dust within the disks with an amplitude of 1.2 mag. The line-luminosity--inclination relation provides a novel way to remove extinction in emission lines and present star formation rate of disk galaxies out to redshift of 1.6.

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Ching-Wa Yip, Alex S. Szalay. 2011-10-04. Extinction in Nebular Luminosities & Star Formation Rate of Disk Galaxies: Inclination Correction. https://arxiv.org/abs/1110.0726

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