Early-type galaxies in the Antlia Cluster: Catalogue and isophotal analysis

CALDERON J.P.; BASSINO L. P.; CELLONE S.A.; GOMEZ, M.

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2018 vol. 477 p. 1760 - 1771

0035-8711

We present a statistical isophotal analysis of 138 early-type galaxiesin the Antlia cluster, located at a distance of ? 35 Mpc. Theobservational material consists of CCD images of four 36 arcmin ×36 arcmin fields obtained with the MOSAIC II camera at the Blanco 4-mtelescope at CTIO. Our present work supersedes previous Antlia studiesin the sense that the covered area is four times larger, the limitingmagnitude is MB ? -9.6 mag, and the surface photometryparameters of each galaxy are derived from Sérsic model fitsextrapolated to infinity. In a companion previous study we focused onthe scaling relations obtained by means of surface photometry, and nowwe present the data, on which the previous paper is based, theparameters of the isophotal fits as well as an isophotal analysis. Foreach galaxy, we derive isophotal shape parameters along the semi-majoraxis and search for correlations within different radial bins. Throughextensive statistical tests, we also analyse the behaviour of thesevalues against photometric and global parameters of the galaxiesthemselves. While some galaxies do display radial gradients in theirellipticity (ɛ) and/or their Fourier coefficients, differencesin mean values between adjacent regions are not statisticallysignificant. Regarding Fourier coefficients, dwarf galaxies usuallydisplay gradients between all adjacent regions, while non-dwarfs tend toshow this behaviour just between the two outermost regions. Globally,there is no obvious correlation between Fourier coefficients andluminosity for the whole magnitude range (-12 ≳ MV≳ -22); however, dwarfs display much higher dispersions at allradii.