THE MORPHOLOGY OF PASSIVELY EVOLVING GALAXIES AT z ∼ 2 FROM HUBBLE SPACE TELESCOPE/WFC3 DEEP IMAGING IN THE HUBBLE ULTRA DEEP FIELD*

We present near-IR images, obtained with the Hubble Space Telescope and the WFC3/IR camera, of six passive and massive galaxies at redshift 1.3 < z < 2.4 (specific star formation rate <10{sup -2} Gyr{sup -1}; stellar mass M {approx} 10{sup 11} M {sub sun}), selected from the Great Observatories Origins Deep Survey. These images, which have a spatial resolution of {approx}1.5 kpc, provide the deepest view of the optical rest-frame morphology of such systems to date. We find that the light profile of these galaxies is regular and well described by a Sersic model with index typical of today's spheroids. Their size, however, is generally much smaller than today's early types of similar stellar masses, with four out of six galaxies having r{sub e} {approx} 1 kpc or less, in quantitative agreement with previous similar measures made at rest-frame UV wavelengths. The images reach limiting surface brightness {mu}{approx} 26.5 mag arcsec{sup -2} in the F160W bandpass; yet, there is no evidence of a faint halo in the galaxies of our sample, even in their stacked image. We also find that these galaxies have very weak 'morphological k-correction' between the rest-frame UV (from the Advanced Camera for Surveys z band) andmore » the rest-frame optical (WFC3 H band): the Sersic index, physical size, and overall morphology are independent or only mildly dependent on the wavelength, within the errors.« less