The Las Campanas Infrared Survey, based on broadband optical and near-infrared photometry, is designed to robustly identify a statistically significant and representative sample of evolved galaxies at redshifts z > 1. We have completed an H-band imaging survey over 1.1 deg 2 of sky in six separate fields. The average 5 detection limit in a 4 00 diameter aperture is H $ 20:8. Here we describe the design of the survey, the observation strategies, data-reduction techniques, and object identification procedures. We present sample near-infrared and optical photometric catalogs for objects identified in two survey fields. The optical images of the Hubble Deep Field-South region obtained from the literature reach 5 detection thresholds in a 4 00 diameter aperture of U $ 24:6, B $ 26:1, V $ 25:6, R $ 25:1, and I $ 24:2 mag. The optical images of the Chandra Deep Field-South region obtained from our own observations reach 5 detection thresholds in a 4 00 diameter aperture of V $ 26:8, R $ 26:2, I $ 25:3, and z 0 $ 23:7 mag. We perform object detection in all bandpasses and identify e 54,000 galaxies over 1408 arcmin 2 of sky in the two fields. Of these galaxies, $14,000 are detected in the H band and $2000 have the colors of evolved galaxies, IÀHe3, at ze1. We find that (1) the differential number counts NðmÞ for the H-band-detected objects has a slope of d log NðmÞ=dm ¼ 0:45 AE 0:01 mag À2 at Hd19 and 0:27 AE 0:01 mag À2 at He19, with a mean surface density %7200 deg À2 mag À1 at H ¼ 19. In addition, we find that (2) the differential number counts for the H-banddetected red objects has a very steep slope, d log Nðm; I À He3Þ=dm ¼ 0:84 AE 0:06 mag À2 at Hd20 and 0:32 AE 0:07 mag À2 at He20, with a mean surface density %3000 deg À2 mag À1 at H ¼ 20. Finally, we find that (3) galaxies with red optical to near-IR colors (IÀH > 3) constitute %20% of the H-band-detected galaxies at Hd21, but only %2% at Hd19. We show that red galaxies are strongly clustered, which results in a strong field-to-field variation in their surface density. Comparisons of observations and predictions based on various formation scenarios indicate that these red galaxies are consistent with mildly evolving early-type galaxies at z $ 1, although with a significant amount of ongoing star formation, as indicated by the large scatter in their VÀI colors.

The Las Campanas Infrared (LCIR) Survey, using the Cambridge Infra‐Red Survey Instrument (CIRSI), reaches H∼21 over nearly 1 deg2. In this paper we present results from 744 arcmin2 centred on the Hubble Deep Field South for which UBVRI optical data are publicly available. Making conservative magnitude cuts to ensure spatial uniformity, we detect 3177 galaxies to H=20.0 in 744 arcmin2 and a further 842 to H=20.5 in a deeper subregion of 407 arcmin2. We compare the observed optical–infrared (IR) colour distributions with the predictions of semi‐analytic hierarchical models and find reasonable agreement. We also determine photometric redshifts, finding a median redshift of ∼0.55. We compare the redshift distributions N(z) of E, Sbc, Scd and Im spectral types with models, showing that the observations are inconsistent with simple passive‐evolution models while semi‐analytic models provide a reasonable fit to the total N(z) but underestimate the number of z∼1 red spectral types relative to bluer spectral types. We also present N(z) for samples of extremely red objects (EROs) defined by optical–IR colours. We find that EROs with R‐H>4 and H<20.5 have a median redshift zm∼1 while redder colour cuts have slightly higher zm. In the magnitude range 194 comprise ∼18 per cent of the observed galaxy population, while in semi‐analytic models they contribute only ∼4 per cent. We also determine the angular correlation function w(θ) for magnitude, colour, spectral type and photometric redshift‐selected subsamples of the data and use the photometric redshift distributions to derive the spatial clustering statistic ξ(r) as a function of spectral type and redshift out to z∼1.2. Parametrizing ξ(r) by ξ(rc,z)=[rc/r∗(z)]‐1.8, where rc is in comoving coordinates, we find that r∗(z) increases by a factor of 1.5–2 from z=0 to z∼1.2. We interpret this as a selection effect – the galaxies selected at z∼1.2 are intrinsically very luminous, about 1–1.5 mag brighter than L∗. When galaxies are selected by absolute magnitude, we find no evidence for evolution in r∗ over this redshift range. Extrapolated to z=0, we find r∗(z=0)∼6.5 h‐1 Mpc for red galaxies and r∗(z=0)∼2–4 h‐1 Mpc for blue galaxies. We also find that, while the angular clustering amplitude of EROs with R‐H>4 or I‐H>3 is up to four times that of the whole galaxy population, the spatial clustering length r∗(z=1) is ∼7.5–10.5 h‐1 Mpc, which is only a factor of ∼1.7 times r∗(z=1) for R‐H<4 and I‐H<3 galaxies lying in a similar redshift and luminosity range. This difference is similar to that observed between red and blue galaxies at low redshifts.

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In this paper we develop machinery for studying sequences of representations of any of the three families of classical Weyl groups, extending work of Church, Ellenberg, Farb, and Nagpal [CEF12], [CEFN14] on the symmetric groups S n to the signed permutation groups B n and the even-signed permutation groups D n . For each family W n , we present an algebraic framework where a sequence V n of W n -representations is encoded into a single object we call an FI W -module. We prove that if an FI W -module V satisfies a simple finite generation condition then the structure of the sequence is highly constrained. One consequence is that the sequence is uniformly representation stable in the sense of Church-Farb, that is, the pattern of irreducible representations in the decomposition of each V n eventually stabilizes in a precise sense. Using the theory developed here we obtain new results about the cohomology of generalized flag varieties associated to the classical Weyl groups, and more generally the r-diagonal coinvariant algebras.We analyze the algebraic structure of the category of FI W -modules, and introduce restriction and induction operations that enable us to study interactions between the three families of groups. We use this theory to prove analogues of Murnaghan's 1938 stability theorem for Kronecker coefficients for the families B n and D n . The theory of FI W -modules gives a conceptual framework for stability results such as these.

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