THE 3D-HST SURVEY: HUBBLE SPACE TELESCOPE WFC3/G141 GRISM SPECTRA, REDSHIFTS, AND EMISSION LINE MEASUREMENTS FOR ∼100,000 GALAXIES

Abstract

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, 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 (PI: B. Weiner). We developed software to automatically and optimally extract interlaced two-dimensional (2D) and one-dimensional (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 redshifts and line strengths (where available) for 22,548 unique objects down to JH(IR) <= 24 (79,609 unique objects down to JH(IR) <= 26). Of these, 5459 galaxies are at z > 1.5 and 9621 are at 0.7 < z < 1.5, where Ha falls in the G141 wavelength coverage. The typical redshift error for JH(IR) <= 24 galaxies is sigma(z) approximate to 0.003 x (1 + z), i.e., one native WFC3 pixel. The 3 sigma limit for emission line fluxes of point sources is 2.1 x 10(-17) erg s(-1) cm(-2). All 2D and 1D spectra, as well as redshifts, line fluxes, and other derived parameters, are publicly available.(18)