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We explore the application of Bayesian image analysis to infer the properties of an SDSS early-type galaxy sample including AGN. We use GALPHAT (Yoon et al. 2010) with a Bayes-factor model comparison to photometrically infer an AGN population and verify this using spectroscopic signatures. Our combined posterior sample for the SDSS sample reveals distinct low and high concentration modes after the point-source flux is modeled. This suggests that ETG parameters are intrinsically bimodal. The bimodal signature was weak when analyzed by GALFIT (Peng et al. 2002, 2010). This led us to create several ensembles of synthetic images to investigate the bias of inferred structural parameters and compare with GALFIT. GALPHAT inferences are less biased, especially for high-concentration profiles: GALPHAT Sersic index $n$, $r_{e}$ and MAG deviate from the true values by $6%$, $7.6%$ and $-0.03 ,mathrm{mag}$, respectively, while GALFIT deviates by $15%$, $22%$ and $-0.09$, mag, respectively. In addition, we explore the reliability for the photometric detection of AGN using Bayes factors. For our SDSS sample with $r_{e}ge 7.92,$arcsec, we correctly identify central point sources with $mathrm{Mag_{PS}}-mathrm{Mag_{Sersic}}le 5$ for $nle6$ and $mathrm{Mag_{PS}}-mathrm{Mag_{Sersic}}le 3$ for $n>6$. The magnitude range increases and classification error decreases with increasing resolution, suggesting that this approach will excel for upcoming high-resolution surveys. Future work will extend this to models that test hypotheses of galaxy evolution through the cosmic time.
Isolated early-type galaxies (iETGs) are evolving in unusually poor environments for this morphological family, which is typical of cluster inhabitants. We investigate the mechanisms driving the evolution of these galaxies. Several studies indicate t
We have carried out surface photometry and an isophotal analysis for a sample of 25 early-type dwarf (dE and dS0) galaxies in the Virgo cluster based on CCD images taken at the VLT with FORS1 and FORS2. For each galaxy we present $B$ and $R$-band sur
We make use of the images from the Sloan Digital Sky Survey Stripe 82 to present an analysis of r band surface brightness profiles and radial color gradients (g - r, u - r) in 111 nearby early-type galaxies (ETGs). With Stripe 82 images, we are able
We present deep B- and R-band surface photometry for a sample of 21 galaxies with morphological types between S0 and Sab. We present radial profiles of surface brightness, colour, ellipticity, position angle and deviations of axisymmetry for all gala
Accretion onto central massive black holes in galaxies is often modelled with the Bondi solution. In this paper we study a generalization of the classical Bondi accretion theory, considering the additional effects of the gravitational potential of th