| Abstract |
An understanding of the star formation process is key to probe the way galaxies form and
evolve. Stars are the fundamental components of galaxies, providing insights to their physical conditions and fundamental parameters. The Star Formation Reference Survey (SFRS)
is a multi-wavelength project, studying the processes of star formation in the local Universe
using a sample of 369 nearby galaxies. The main theme of this work is the activity classification of the 47 galaxies in the SFRS which have available optical spectra, in order to
discriminate the galaxies hosting active galactic nuclei (AGN), fueled by accretion on a central black hole, from those who are dominated by star formation processes. We analyze the
spectra of the galaxies in the 3800°A − 7800°A wavelength range obtained with the FAST spectrograph at the 60-inch telescope of the Fred Lawrence Whipple Observatory (FLWO) at Mt.
Hopkins in Arizona. We measure prominent emission lines, and use optical spectroscopic diagnostics in order to determine their activity classification. We find that the sample consists
of 32 star-forming galaxies, 6 LINERs, 8 Composite objects, and 1 Seyfert galaxy.
We find that both methods give similar
metallicity results. The 03N2-method gives an average metallicity of 12 + log(O/H) = 8.70 for
star-forming galaxies, 12 + log(O/H) = 8.79 for LINERs, 12 + log(O/H) = 8.77 for composite
objects, and 12 + log(O/H) = 8.52 for the Seyfert galaxy. The N2-method, yields an average
metallicity of: 12 + log(O/H) = 8.72 for the star-forming galaxies and 12 + log(O/H) = 8.71 for composite objects.
These metallicity measurements are similar to Galactic metallicity, which
suggests that there is not a large population of low metallicity objects in the sample.
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Optical activity diagnostics for the star formation reference survey (SFRS)
