Abstract

Studying stellar populations in local barred galaxies using structural decomposition of multiband galaxy images
Galaxy structure in the low-redshift universe
Sandor Kruk
Chris Lintott (Oxford) and the Galaxy Zoo Science Team
University of Oxford
We present the results of a three-component (disc/bulge/bar) multiwavelength photometric decomposition in five SDSS bands, ugriz, on the largest sample of barred galaxies to date. Using morphologies from the Galaxy Zoo citizen science project, we have created a representative sample of ~2,000 local barred galaxies (with redshifts lower than 0.06) which have been visually inspected for the presence of a bar. For a detailed structural analysis, we fitted this large sample with a disc, a bulge and a bar using the novel GALFITM software developed by the MegaMorph project. We estimate physical quantities such as the bar and bulge-to-total luminosity ratios, Sérsic indices and the colour distribution of the components. We also use our fitting to identify a subsample of galaxies with bars offset from their disc centres. By comparing the barred galaxies with a mass-matched sample of unbarred late-type galaxies, we examine the connection between the presence of a large-scale galactic bar and the properties of discs and bulges. We observe a clear difference in colour between the corresponding discs and bulges of the barred and unbarred galaxies suggesting different underlying stellar populations and star formation rates.

Schedule

16:30 - 18:00
17:15
Tuesday
EX - C3 (150)

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