  We present the analysis of the deepest near-UV image obtained with HST using
the WFPC2(F300W) as part of the parallel observations of the Ultra Deep Field
campaign. The U-band 10sigma limiting magnitude measured over 0.2 arcsec square
is m(AB)=27.5 which is 0.5 magnitudes deeper than that in the HDF-North. We
matched the U-band catalog with those in the ACS images taken during the GOODS
observations of the CDF-South and obtained photometric-z for 306 matched
objects. We find that the UV-selected galaxies span all the major morphological
types at 0.2<z_phot<1.2. However, disks are more common at lower redshifts,
0.2<z_phot<0.8. Higher-z objects (0.7<z_phot<1.2) are on average bluer than
lower-z and have spectral type typical of starbursts. Their morphologies are
compact, peculiar or low surface brightness galaxies. The average half-light
radius (rest-frame 1200--1800 A) of the UV-selected galaxies at 0.66<z_
phot<1.5 is 0.26 +- 0.01 arcsec (2.07 +- 0.08 kpc). The UV-selected galaxies
are on average fainter (M_B=-18.43+-0.13) than Lyman Break Galaxies
(M_B=-23+-1). Our sample includes early-type galaxies that are presumably
massive and forming stars only in their cores, as well as starburst-type
systems that are more similar to the LBGs, although much less luminous. This
implies that even the starbursts in our sample are either much less massive
than LBGs or are forming stars at a much lower rate or both. The low surface
brightness galaxies have no overlap with the LBGs and form an interesting new
class of their own.
