Integral Field Spectroscopy of Compact Elliptical Galaxies.

Abstract

The rare compact elliptical galaxies (cEs) are thought to have been formed through atidal stripping process of a once much larger progenitor, as they do not adhere to themass-size, mass-metalicity and black hole-bulge mass scaling relations like their moremassive early-type cousins. By using observations taken with the FLAMES/GI-RAFFE integral field spectrographs of the European Southern Observatory’s (ESO)8.2m Very Large Telescope (VLT), we searched for evidence for the presence ofoverly massive SMBHs in our sample of cEs. The raw reduction was performed bythe workflow environment EsoReflex, Voronoi binned spectra from 4 target cEs wereobtained using the VorBin method. We performed a full spectrum fit of cE spectrausing the Penalized Pixel Fitting (pPXF) method, to extract resolved kinematics i.ethe Line Of Sight Velocity Distribution (LOSVD). Dynamical mass estimates of or-der 109Mwere obtained. Dynamical to stellar mass ratios for 3 cEs (NGC5846cE,NGC3268cE1 and AHcE0) reveal the likely presence of an overly massive SMBH,favoring the tidal stripping scenario for cE formation