Automatic Morphological Classification of Galaxies in SDSS/GALEX Based on Catalog Photometry

Mathematics – Logic

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

Scientific paper

Galaxies have been historically classified based on their morphologies, requiring visual identification of their defining structural features. This can be extremely time consuming and especially difficult for galaxies that are poorly resolved or at certain orientations. To quell these issues, a new automated proxy for visual morphological classification is needed. We utilized photometric magnitudes and angular size information from the Sloan Digital Sky Survey (SDSS) and Galaxy Evolution Explorer (GALEX) data releases to categorize galaxies at redshifts near z=0.1 as elliptical, lenticular, spiral, or irregular. A galaxy of interest has its catalog photometry corrected for redshift and is then compared to galaxies of known type from the Third Reference Catalog of Bright Galaxies (RC3) by a chi-squared goodness-of-fit analysis of their spectral energy distributions, radial light concentrations, ellipticities, and UV-to-optical size ratios. Testing this method on the RC3 galaxies themselves yielded probabilities that each of the four outcomes result from each source type. Overall, results are drawn from the correct sources a majority of the time, at 52% for ellipticals, 45% for lenticulars, 61% for spirals, and 71% for irregular galaxies. These likelihoods held up when the method was tested on galaxies near the target z 0.1 redshift with rough classifications available from the COSMOS survey. Finally, the method was applied to numerous galaxies at z 0.1 with established star formation rates and stellar masses to reveal connections between these values and galactic type. Most notably, lenticular galaxies, while of comparable mass to ellipticals, were shown to be undergoing more current star formation, and irregular galaxies were observed to contain generally less stellar material than spirals. This project was supported by the National Science Foundation as part of the Summer 2010 Astronomy REU Program at Indiana University.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

Automatic Morphological Classification of Galaxies in SDSS/GALEX Based on Catalog Photometry does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Automatic Morphological Classification of Galaxies in SDSS/GALEX Based on Catalog Photometry, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Automatic Morphological Classification of Galaxies in SDSS/GALEX Based on Catalog Photometry will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1402010

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.