We present interferometric CO observations made with the Combined Array for Millimeter-wave Astronomy (CARMA) of galaxies from the Extragalactic Database for Galaxy Evolution survey (EDGE). These galaxies are selected from the Calar Alto Legacy Integral Field Area (CALIFA) sample, mapped with optical integral field spectroscopy. EDGE provides good quality CO data (3σ sensitivitity Σ mol ∼ 11 M pc −2 before inclination correction, resolution ∼ 1.4 kpc) for 126 galaxies, constituting the largest interferometric CO survey of galaxies in the nearby universe. We describe the survey, the data characteristics, the data products, and present initial science results. We find that the exponential scale-lengths of the molecular, stellar, and star-forming disks are approximately equal, and galaxies that are more compact in molecular gas than in stars tend to show signs of interaction. We characterize the molecular to stellar ratio as a function of Hubble type and stellar mass, present preliminary results on the resolved relations between the molecular gas, stars, and star formation rate, and discuss the dependence of the resolved molecular depletion time on stellar surface density, nebular extinction, and gas metallicity. EDGE provides a key dataset to address outstanding topics regarding gas and its role in star formation and galaxy evolution, which will be publicly available on completion of the quality assessment.

The [CII] 157.74 µm transition is the dominant coolant of the neutral interstellar gas, and has great potential as a star formation rate (SFR) tracer. Using the Herschel KINGFISH sample of 46 nearby galaxies, we investigate the relation of [CII] surface brightness and luminosity with SFR. We conclude that [CII] can be used for measurements of SFR on both global and kiloparsec scales in normal star-forming galaxies in the absence of strong active galactic nuclei (AGN). The uncertainty of the Σ [CII] − Σ SFR calibration is ±0.21 dex. The main source of scatter in the correlation is associated with regions that exhibit warm IR colors, and we provide an adjustment based on IR color that reduces the scatter. We show that the color-adjusted Σ [CII] − Σ SFR correlation is valid over almost 5 orders of magnitude in Σ SFR , holding for both normal star-forming galaxies and non-AGN luminous infrared galaxies. Using [CII] luminosity instead of surface brightness to estimate SFR suffers from worse systematics, frequently underpredicting SFR in luminous infrared galaxies even after IR color adjustment (although this depends on the SFR measure employed). We suspect that surface brightness relations are better behaved than the luminosity relations because the former are more closely related to the local far-UV field strength, most likely the main parameter controlling the efficiency of the conversion of far-UV radiation into gas heating. A simple model based on Starburst99 populationsynthesis code to connect SFR to [CII] finds that heating efficiencies are 1% − 3% in normal galaxies.

We present 0 ′′ .2-resolution Atacama Large Millimeter/submillimeter Array observations at 870 µm for 25 Hα-seleced star-forming galaxies around the main-sequence at z = 2.2 − 2.5. We detect significant 870 µm continuum emission in 16 (64%) of these galaxies. The high-resolution maps reveal that the dust emission is mostly radiated from a single region close to the galaxy center. Exploiting the visibility data taken over a wide uv distance range, we measure the half-light radii of the rest-frame far-infrared emission for the best sample of 12 massive galaxies with log(M * /M ⊙ ) >11. We find nine galaxies to be associated with extremely compact dust emission with R 1/2,870µm < 1.5 kpc, which is more than a factor of 2 smaller than their rest-optical sizes, R 1/2,1.6µm =3.2 kpc, and is comparable with optical sizes of massive quiescent galaxies at similar redshifts. As they have an exponential disk with Sérsic index of n 1.6µm =1.2 in the rest-optical, they are likely to be in the transition phase from extended disks to compact spheroids. Given their high star formation rate surface densities within the central 1 kpc of ΣSFR 1kpc = 40 M ⊙ yr −1 kpc −2 , the intense circumnuclear starbursts can rapidly build up a central bulge with ΣM * ,1kpc > 10 10 M ⊙ kpc −2 in several hundred Myr, i.e. by z ∼ 2. Moreover, ionized gas kinematics reveal that they are rotation-supported with an angular momentum as large as that of typical star-forming galaxies at z = 1 − 3. Our results suggest bulges are commonly formed in extended rotating disks by internal processes, not involving major mergers.

We report high quality, Hα or CO rotation curves (RCs) to several Re for 41 large, massive, star-forming disk galaxies (SFGs), across the peak of cosmic galaxy evolution (z~0.67-2.45), taken with the ESO-VLT, the LBT and IRAM-NOEMA. Most RC41 SFGs have reflection symmetric RCs plausibly described by equilibrium dynamics. We fit the major axis position-velocity cuts with beam-convolved, forward modeling with a bulge, a turbulent rotating disk, and a dark matter (DM) halo. We include priors for stellar and molecular gas masses, optical light effective radii and inclinations, and DM masses from abundance matching scaling relations. Two-thirds or more of the z ³ 1.2 SFGs are baryon dominated within a few Re of typically 5.5 kpc, and have DM fractions less than maximal disks ( = 0.12). At lower redshift (z<1.2) that fraction is less than one-third. DM fractions correlate inversely with the baryonic angular momentum parameter, baryonic surface density and bulge mass. Inferred low DM fractions cannot apply to the entire disk & halo but more plausibly reflect a flattened, or cored, inner DM density distribution. The typical central 'DM deficit' in these cores relative to NFW distributions is ~30 % of the bulge mass. The observations are consistent with rapid radial transport of baryons in the first generation massive gas rich halos forming globally gravitationally unstable disks, and leading to efficient build-up of massive bulges and central black holes. A combination of heating due to dynamical friction and AGN feedback may drive DM out of the initial cusps.

We use Herschel 70 to 160 µm images to study the size of the far-infrared emitting region in about 400 local galaxies and quasar (QSO) hosts. The sample includes normal 'main-sequence' star-forming galaxies, as well as infrared luminous galaxies and Palomar-Green QSOs, with different levels and structures of star formation. Assuming Gaussian spatial distribution of the far-infrared (FIR) emission, the excellent stability of the Herschel point spread function (PSF) enables us to measure sizes well below the PSF width, by subtracting widths in quadrature. We derive scalings of FIR size and surface brightness of local galaxies with FIR luminosity, with distance from the star-forming main-sequence, and with FIR color. Luminosities L FIR ∼10 11 L ⊙ can be reached with a variety of structures spanning 2 dex in size. Ultraluminous L FIR 10 12 L ⊙ galaxies far above the main-sequence inevitably have small R e,70 ∼0.5 kpc FIR emitting regions with large surface brightness, and can be close to optically thick in the FIR on average over these regions. Compared to these local relations, first ALMA sizes for the dust emission regions in high redshift galaxies, measured at somewhat longer rest wavelengths, suggest larger sizes at the same IR luminosity. We report a remarkably tight relation with 0.15 dex scatter between FIR surface brightness and the ratio of [Cii] 158 µm emission and FIR emission -the so-called [Cii]-deficit is more tightly linked to surface brightness than to FIR luminosity or FIR color. Among 33 z≤0.1 PG QSOs with typical L FIR /L Bol,AGN ≈0.1, 19 have a measured 70 µm half light radius, with median R e,70 =1.1 kpc. This is consistent with the FIR size for galaxies with similar L FIR but lacking a QSO, in accordance with a scenario where the rest FIR emission of these types of QSOs is, in most cases, due to host star formation.