THE SINS SURVEY: SINFONI INTEGRAL FIELD SPECTROSCOPY OF z∼ 2 STAR-FORMING GALAXIES

Abstract

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 10 10 M star-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 × 10 10 M , ≈70 M 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.