The SINS Survey: SINFONI Integral Field Spectroscopy of z ~ 2 Star-forming Galaxies

We present the Spectroscopic Imaging survey in the near-infrared (near-IR) with SINFONI (SINS) of high-redshift galaxies. With 80 objects observed and 63 detected in at least one rest-frame optical nebular emission line, mainly Hα, SINS represents the largest survey of spatially resolved gas kinematics, morphologies, and physical properties of star-forming galaxies at z ~ 1-3. We describe the selection of the targets, the observations, and the data reduction. We then focus on the "SINS Hα sample," consisting of 62 rest-UV/optically selected sources at 1.3 < z < 2.6 for which we targeted primarily the Hα and [N II] emission lines. Only ≈30% of this sample had previous near-IR spectroscopic observations. The galaxies were drawn from various imaging surveys with different photometric criteria; as a whole, the SINS Hα sample covers a reasonable representation of massive M _sstarf gsim 10¹⁰ M _sunstar-forming galaxies at z ≈ 1.5-2.5, with some bias toward bluer systems compared to pure K-selected samples due to the requirement of secure optical redshift. The sample spans 2 orders of magnitude in stellar mass and in absolute and specific star formation rates, with median values ≈3 × 10¹⁰ M _sun, ≈70 M _sun yr^-1, and ≈3 Gyr^-1. The ionized gas distribution and kinematics are spatially resolved on scales ranging from ≈1.5 kpc for adaptive optics assisted observations to typically ≈4-5 kpc for seeing-limited data. The Hα morphologies tend to be irregular and/or clumpy. About one-third of the SINS Hα sample galaxies are rotation-dominated yet turbulent disks, another one-third comprises compact and velocity dispersion-dominated objects, and the remaining galaxies are clear interacting/merging systems; the fraction of rotation-dominated systems increases among the more massive part of the sample. The Hα luminosities and equivalent widths suggest on average roughly twice higher dust attenuation toward the H II regions relative to the bulk of the stars, and comparable current and past-averaged star formation rates.

Based on observations obtained at the Very Large Telescope (VLT) of the European Southern Observatory, Paranal, Chile (ESO Programme IDs 070.A-0229, 070.B-0545, 073.B-9018, 074.A-9011, 075.A-0466, 076.A-0527, 077.A-0576, 078.A-0055, 078.A-0600, 079.A-0341, 080.A-0330, 080.A-0635, and 080.A-0339).