Publication Date:
2016-08-17
Description:
We perform automated bulge + disc decomposition on a sample of ~7500 galaxies from the Galaxy And Mass Assembly (GAMA) survey in the redshift range of 0.002 〈 z 〈 0.06 using Structural Investigation of Galaxies via Model Analysis, a wrapper around galfit 3. To achieve robust profile measurements, we use a novel approach of repeatedly fitting the galaxies, varying the input parameters to sample a large fraction of the input parameter space. Using this method, we reduce the catastrophic failure rate significantly and verify the confidence in the fit independently of 2 . Additionally, using the median of the final fitting values and the 16th and 84th percentile produces more realistic error estimates than those provided by galfit , which are known to be underestimated. We use the results of our decompositions to analyse the stellar mass – half-light radius relations of bulges, discs and spheroids. We further investigate the association of components with a parent disc or elliptical relation to provide definite z = 0 disc and spheroid $\mathcal {M_\star }\text{--}R_{\rm e}$ relations. We conclude by comparing our local disc and spheroid $\mathcal {M_\star }\text{--}R_{\rm e}$ to simulated data from eagle and high-redshift data from Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey-Ultra Deep Survey. We show the potential of using the $\mathcal {M_\star }\text{--}R_{\rm e}$ relation to study galaxy evolution in both cases but caution that for a fair comparison, all data sets need to be processed and analysed in the same manner.
Print ISSN:
0035-8711
Electronic ISSN:
1365-2966
Topics:
Physics
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