High‐resolution morphology and surface photometry of KIG 685 and KIG 895 with ARGOS+LUCI using the Large Binocular Telescope

Abstract

AbstractWe aim to refine the sample of isolated early‐type galaxies in the Analysis of the interstellar Medium of Isolated Galaxies (AMIGA) catalog via high‐resolution imaging. Here, we report the result from a pilot study investigating two candidates, KIG 685 and KIG 895, in K‐band with the laser guide star and wavefront sensing facility ARGOS using the Large Binocular Telescope (LBT). Observations, obtained during the commissioning time, achieved a point spread function (PSF) of ≈0.25″. We present the data reduction and the PSF analysis from the best closed‐loop exposures to investigate the galaxies' morphological structure, including their nuclear region. We used PROFILER for the decomposition of the azimuthal 1D light distribution and GALFIT for the 2D analysis, accounting for ARGOS's PSF. KIG 685 was found to be a S0 galaxy and has been modeled with two Sérsic components representing a pseudobulge (n1D = 2.87 ± 0.21, n2D = 2.29 ± 0.10) and a disk (n1D = 0.95 ± 0.16, n2D = 0.78 ± 0.10). Nearly symmetric ring‐/shell‐like structures emerge after subtracting the GALFIT model from the image. KIG 895 shows a clear irregular arm‐like structure, in which the northern outer arm is reminiscent of a tail. The galaxy body is a disk, best fitted by a single Sérsic profile (n1D = 1.22 ± 0.1; n2D = 1.32 ± 0.12), that is, KIG 895 is a bulge‐less, very late‐type spiral. ARGOS high‐resolution images clearly showed interaction signatures in KIG 895. We suggest that the ring‐/shell‐like residuals in KIG 685, a bona fide early‐type galaxy, point toward a past accretion event.