Galaxy structure in the low-redshift universe
Studying stellar populations in local barred galaxies using structural decomposition of multiband galaxy images
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.


16:30 - 18:00
EX - C3 (150)