CIII] Emission in Star-forming Galaxies at z ~ 1
  The CIII]{\lambda}{\lambda}1907, 1909 rest-frame UV emission doublet has
recently been detected in galaxies during the epoch of reionization (z > 6),
with high equivalent width (>10 {\AA}, rest frame). Currently, it is possible
to obtain much more detailed information for star-forming galaxies at
significantly lower redshift. Accordingly, studies of their far-UV spectra are
useful for understanding the factors modulating the strength of CIII] emission.
We present the first statistical sample of CIII] emission measurements in
star-forming galaxies at z ~ 1. Our sample is drawn from the DEEP2 survey and
spans the redshift 0.64 < z < 1.35 (<z> = 1.08). We find that the median
equivalent width (EW) of individual CIII] detections in our sample (1.30 {\AA})
is much smaller than the typical value observed thus far at z > 6. Furthermore,
out of 184 galaxies with coverage of CIII], only 40 have significant
detections. Galaxies with individual CIII] detections have bluer colors and
lower luminosities on average than those without, implying that strong CIII]
emitters are in general young and low-mass galaxies without significant dust
extinction. Using stacked spectra, we further investigate how CIII] strength
correlates with multiple galaxy properties (M_B, U-B, M*, star-formation rate,
specific star-formation rate) and rest-frame near-UV (FeII* and MgII) and
optical [OIII] and H{\beta}) emission line strengths. These results provide a
detailed picture of the physical environment in star-forming galaxies at z ~ 1,
and motivate future observations of strong CIII] emitters at similar redshifts.
