The 3D-HST Survey: Hubble Space Telescope WFC3/G141 grism spectra,
  redshifts, and emission line measurements for $\sim 100,000$ galaxies
  We present reduced data and data products from the 3D-HST survey, a 248-orbit
HST Treasury program. The survey obtained WFC3 G141 grism spectroscopy in four
of the five CANDELS fields: AEGIS, COSMOS, GOODS-S, and UDS, along with WFC3
$H_{140}$ imaging, parallel ACS G800L spectroscopy, and parallel $I_{814}$
imaging. In a previous paper (Skelton et al. 2014) we presented photometric
catalogs in these four fields and in GOODS-N, the fifth CANDELS field. Here we
describe and present the WFC3 G141 spectroscopic data, again augmented with
data from GO-1600 in GOODS-N. The data analysis is complicated by the fact that
no slits are used: all objects in the WFC3 field are dispersed, and many
spectra overlap. We developed software to automatically and optimally extract
interlaced 2D and 1D spectra for all objects in the Skelton et al. (2014)
photometric catalogs. The 2D spectra and the multi-band photometry were fit
simultaneously to determine redshifts and emission line strengths, taking the
morphology of the galaxies explicitly into account. The resulting catalog has
98,663 measured redshifts and line strengths down to $JH_{IR}\leq 26$ and
22,548 with $JH_{IR}\leq 24$, where we comfortably detect continuum emission.
Of this sample 5,459 galaxies are at $z>1.5$ and 9,621 are at $0.7<z<1.5$,
where H$\alpha$ falls in the G141 wavelength coverage. Based on comparisons
with ground-based spectroscopic redshifts, and on analyses of paired galaxies
and repeat observations, the typical redshift error for $JH_{IR}\leq 24$
galaxies in our catalog is $\sigma_z \approx 0.003 \times (1+z)$, i.e., one
native WFC3 pixel. The $3\sigma$ limit for emission line fluxes of point
sources is $1.5\times10^{-17}$ ergs s$^{-1}$ cm$^{-2}$. We show various
representations of the full dataset, as well as individual examples that
highlight the range of spectra that we find in the survey.
