GOODS-Herschel:dust attenuation properties of UV selected high redshift
  galaxies
  We study dust attenuation at UV wavelengths at high redshift, where the UV is
redshifted to the observed visible. In particular, we search for a UV bump and
related implications for dust attenuation determinations. We use data in the
CDFS, obtained in intermediate and broad band filters by the MUSYC project, to
sample the UV rest-frame of 751 galaxies with 0.95<z<2.2. When available,
Herschel/PACS data (GOODS-Herschel project), and Spitzer/MIPS measurements, are
used to estimate the dust emission. The SED of each source is fit using the
CIGALE code. The amount of dust attenuation and the dust attenuation curve are
obtained as outputs of the SED fitting process, together with other parameters
linked to the SFH. The global amount of dust attenuation at UV wavelengths is
found to increase with stellar mass and to decrease as UV luminosity increases.
A UV bump at 2175A is securely detected in 20% of the galaxies, and the mean
amplitude of the bump for the sample is similar to that observed in the LMC
supershell region. This amplitude is found to be lower in galaxies with very
high SSFRs, and 90% of the galaxies exhibiting a secure bump are at z<1.5. The
attenuation curve is confirmed to be steeper than that of local starburst
galaxies for 20$% of the galaxies. The large dispersion found for these two
parameters describing the attenuation law is likely to reflect a wide diversity
of attenuation laws among galaxies. The relations between dust attenuation,
IR-to-UV flux ratio, and the slope of the UV continuum are derived for the mean
attenuation curve found for our sample. Deviations from the average trends are
found to correlate with the age of the young stellar population and the shape
of the attenuation curve.(abriged)
