We present an Atacama Large Millimeter/submillimeter Array (ALMA) Cycle 0 survey of 126 submillimeter sources from the LABOCA ECDFS Submillimeter Survey (LESS). Our 870 μm survey with ALMA (ALESS) has produced maps ∼3× deeper and with a beam area ∼200× smaller than the original LESS observations, doubling the current number of interferometrically-observed submillimeter sources. The high resolution of these maps allows us to resolve sources that were previously blended and accurately identify the origin of the submillimeter emission. We discuss the creation of the ALESS submillimeter galaxy (SMG) catalog, including the main sample of 99 SMGs and a supplementary sample of 32 SMGs. We find that at least 35% (possibly up to 50%) of the detected LABOCA sources have been resolved into multiple SMGs, and that the average number of SMGs per LESS source increases with LESS flux density. Using the (now precisely known) SMG positions, we empirically test the theoretical expectation for the uncertainty in the single-dish source positions. We also compare our catalog to the previously predicted radio/mid-infrared counterparts, finding that 45% of the ALESS SMGs were missed by this method. Our ∼1. 6 resolution allows us to measure a size of ∼9 kpc × 5 kpc for the rest-frame ∼300 μm emission region in one resolved SMG, implying a star formation rate surface density of 80 M yr −1 kpc −2 , and we constrain the emission regions in the remaining SMGs to be <10 kpc. As the first statistically reliable survey of SMGs, this will provide the basis for an unbiased multiwavelength study of SMG properties.

We present the evolution of the luminosity-size and stellar massYsize relations of luminous (L V k 3:4 ; 10 10 h À2 70 L) and massive (M Ã k 3 ; 10 10 h À2 70 M) galaxies in the last $11 Gyr. We use very deep near-infrared images of the Hubble Deep FieldYSouth and the MS 1054-03 field in the J s , H, and K s bands from FIRES to retrieve the sizes in the optical rest frame for galaxies with z > 1. We combine our results with those from GEMS at 0:2 < z < 1 and SDSS at z $ 0:1 to achieve a comprehensive picture of the optical rest-frame size evolution from z ¼ 0 to 3. Galaxies are differentiated according to their light concentration using the Sérsic index n. For less concentrated objects, the galaxies at a given luminosity were typically $3 AE 0:5 (AE2) times smaller at z $ 2:5 than those we see today. The stellar massYsize relation has evolved less: the mean size at a given stellar mass was $2 AE 0:5 times smaller at z $ 2:5, evolving proportionally to (1 þ z) À0:40AE0:06. Simple scaling relations between dark matter halos and baryons in a hierarchical cosmogony predict a stronger (although consistent within the error bars) than observed evolution of the stellar massYsize relation. The observed luminosity-size evolution out to z $ 2:5 matches well recent infall model predictions for Milky WayYtype objects. For low-n galaxies, the evolution of the stellar massYsize relation would follow naturally if the individual galaxies grow inside out. For highly concentrated objects, the situation is as follows: at a given luminosity, these galaxies were $2:7 AE 1:1 times smaller at z $ 2:5 (or, put differently, were typically $2:2 AE 0:7 mag brighter at a given size than they are today), and at a given stellar mass the size has evolved proportionally to (1 þ z) À0:45AE0:10 .

We use very deep near-infrared photometry of the Hubble Deep Field-South taken with ISAAC on the Very Large Telescope to identify a population of high-redshift galaxies with rest-frame optical colors similar to those of nearby galaxies. The galaxies are chosen by their infrared colors , aimed at selecting galaxies with J ϪK 1 2.3 s s redshifts above 2. When applied to our data set, we find 14 galaxies with , corresponding to a surface K ! 22.5 s density of arcmin. The photometric redshifts all lie above 1.9, with a median of 2.6 and an rms of Ϫ2 3 ‫ע‬ 0.8 0.7. The spectral energy distributions of these galaxies show a wide range. One is very blue in the rest-frame UV and satisfies the normal Lyman break criteria for high-redshift, star-forming galaxies. Others are quite red throughout the observed spectral range and are extremely faint in the optical, with a median. Hence, V p 26.6 these galaxies would not be included in photometric samples based on optical ground-based data, and spectroscopic follow-up is difficult. The spectral energy distributions often show a prominent break, identified as the Balmer break or the 4000 Å break. The median age is 1 Gyr when fitted with a constant star formation model with dust or 0.7 Gyr when fitted with a single burst model. Although significantly younger ages cannot be excluded when a larger range of models is allowed, the results indicate that these galaxies are among the oldest at these redshifts. The volume density to is half that of Lyman break galaxies at. Since the mass-to-light ratios K p 22.5 z ≈ 3 s of the red galaxies are likely to be higher, the stellar mass density is inferred to be comparable to that of Lyman break galaxies. These red galaxies may be the descendants of galaxies that started to form stars at very high redshifts, and they may evolve into the most massive galaxies at low redshift.

We make use of deep 1.2 mm-continuum observations (12.7µJy/beam RMS) of a 1 arcmin 2 region in the Hubble Ultra Deep Field (HUDF) to probe dust-enshrouded star formation from 330 Lyman-break galaxies spanning the redshift range z = 2-10 (to ∼2-3 M ⊙ /yr at 1σ over the entire range). Given the depth and area of ASPECS, we would expect to tentatively detect 35 galaxies extrapolating the Meurer z ∼ 0 IRX-β relation to z ≥ 2 (assuming T d ∼ 35 K). However, only 6 tentative detections are found at z 2 in ASPECS, with just three at >3σ. Subdividing z = 2-10 galaxies according to stellar mass, U V luminosity, and U V -continuum slope and stacking the results, we only find a significant detection in the most massive (>10 9.75 M ⊙ ) subsample, with an infrared excess (IRX=L IR /L UV ) consistent with previous z ∼ 2 results. However, the infrared excess we measure from our large selection of sub-L * (<10 9.75 M ⊙ ) galaxies is 0.11 +0.32 −0.42 ±0.34 (bootstrap and formal uncertainties) and 0.14 +0.15 −0.14 ±0.18 at z = 2-3 and z = 4-10, respectively, lying below even an SMC IRX-β relation (95% confidence). These results demonstrate the relevance of stellar mass for predicting the IR luminosity of z 2 galaxies. We find that the evolution of the IRX-stellar mass relationship depends on the evolution of the dust temperature. If the dust temperature increases monotonically with redshift (∝ (1 + z) 0.32 ) such that T d ∼ 44-50 K at z ≥ 4, current results are suggestive of little evolution in this relationship to z ∼ 6. We use these results to revisit recent estimates of the z ≥ 3 star-formation rate density.

Additional information: Use policyThe full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details. ) submillimeter galaxies (SMGs) from the ALESS survey of the Extended Chandra Deep Field South. This dust imaging traces the dust-obscured star formation in thesez 2.5 galaxies on ∼1.3 kpc scales. The emission has a median effective radius of R e = 0 24 ± 0 02, corresponding to a typical physical size of = R e 1.8±0.2 kpc. We derive a median Sérsic index of n=0.9±0.2, implying that the dust emission is remarkably disk-like at the current resolution and sensitivity. We use different weighting schemes with the visibilities to search for clumps on 0 12(∼1.0 kpc) scales, but we find no significant evidence for clumping in the majority of cases. Indeed, we demonstrate using simulations that the observed morphologies are generally consistent with smooth exponential disks, suggesting that caution should be exercised when identifying candidate clumps in even moderate signal-to-noise ratio interferometric data. We compare our maps to comparable-resolution Hubble Space Telescope H 160 -band images, finding that the stellar morphologies appear significantly more extended and disturbed, and suggesting that major mergers may be responsible for driving the formation of the compact dust disks we observe. The stark contrast between the obscured and unobscured morphologies may also have implications for SED fitting routines that assume the dust is co-located with the optical/near-IR continuum emission. Finally, we discuss the potential of the current bursts of star formation to transform the observed galaxy sizes and light profiles, showing that thez 0 descendants of these SMGs are expected to have stellar masses, effective radii, and gas surface densities consistent with the most compact massive ( *M 1-2×1011  M ) earlytype galaxies observed locally.