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(Abridged) The Las Campanas Infrared Survey, based on broad-band 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 square degrees of sky in six separate fields. The average 5 sigma detection limit in a four arcsecond diameter aperture is H ~ 20. 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. We perform object detection in all bandpasses and identify ~ 54,000 galaxies over 1,408 square arcminutes of sky in the two fields. Of these galaxies, ~ 14,000 are detected in the H-band and ~ 2,000 have the colors of evolved galaxies, I - H >3, at z > 1. We find that (1) the differential number counts N(m) for the H-band detected objects has a slope of 0.44 at H < 19 and 0.27 for H > 19. In addition, we find that (2) the differential number counts for the H detected red objects has a slope of 0.85 at H < 20 and 0.32 at H > 20, with a mean surface density ~ 3,000 degree^{-2} mag^{-1} at H=20. Finally, we find that (3) galaxies with red optical to near-IR colors (I-H > 3) constitute ~ 20% of the H detected galaxies at H ~ 21, but only 2% at H = 19. 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 on-going star formation as indicated by the large scatter in their V-I colors., 48 pages, 13 figures, accepted for publication in the Astrophysical Journal

We present the first detection of a gravitational depletion signal at near-infrared wavelengths, based on deep panoramic images of the cluster Abell 2219 (z=0.22) taken with the Cambridge Infrared Survey Instrument (CIRSI) at the prime focus of the 4.2m William Herschel Telescope. Infrared studies of gravitational depletion offer a number of advantages over similar techniques applied at optical wavelengths, and can provide reliable total masses for intermediate redshift clusters. Using the maximum likelihood technique developed by Schneider, King & Erben (1999), we detect the gravitational depletion at the 3 sigma confidence level. By modeling the mass distribution as a singular isothermal sphere and ignoring uncertainty in the unlensed number counts, we find an Einstein radius of 13.7 +3.9/-4.2 arcsec (66% confidence limit). This corresponds to a projected velocity dispersion of approximately 800 km/s, in agreement with constraints from strongly-lensed features. For a Navarro, Frenk and White mass model, the radial dependence observed indicates a best-fitting halo scale length of 125/h kpc}. We investigate the uncertainties arising from the observed fluctuations in the unlensed number counts, and show that clustering is the dominant source of error. We extend the maximum likelihood method to include the effect of incompleteness, and discuss the prospects of further systematic studies of lensing in the near-infrared band., 12 pages, 12 figures. Accepted for publication in MNRAS, minor changes

This paper describes the results of a test program to evaluate four Rockwell HAWAII and two PICNIC near IR array detectors with a view to their application in imaging, spectroscopy and in fast telescope tracking and interferometer fringe detection. Results of the laboratory test of the arrays are presented, together with a guide for their general operation.

COHSI was successfully commissioned at the United Kingdom IR Telescope on Mauna Kea during a seven night observing run which coincided with this conference. Here we briefly describe the instrument and give a preliminary report on its performance at this time. The suppression optics and masks worked extremely well and the instrument background was found to be very low.

We have built a panoramic wide field near infrared imaging camera based on 4 Rockwell HAWAII 1024 X 1024 detectors. The baseline survey instrument operates in the region 0.8 to 1.8 micrometers on non-IR optimized telescopes with an upgrade at K band in 1999. The instrument was commission on the 2.5m INT and 4.2m WHT telescopes in December 1997 and January 1998. The main design goals in this project were to produce a highly productive astronomical instrument in a very short space of time and for low cost. Survey instruments are by their nature very versatile and CIRSI will support the wide range of astronomical interests at the Institute of Astronomy. Furthermore, since CIRSI is a traveling instrument and we are able to operate at a number of different telescopes to take opportunity of a range of image sizes and scales.

There are difficult problems involved in building a near-infrared interferometer which uses more than two elements simultaneously. These problems have been overcome at the Cambridge Optical Aperture Synthesis Telescope(COAST). This has allowed us to make the first closure phase measurements on an astronomical source in the infrared. We describe a scheme for fast, low noise readout of an infrared focal-plane array detector, capable of adequately sampling pupil plane fringes on three simultaneous baselines, as well as a procedure for aligning a many-component beam-combiner in the infrared. Finally, the performance of the working COAST infrared system is discussed.

We are currently building a panoramic wide field near infrared imaging camera based on 4 Rockwell Hawaii HgCdTe 10242 detectors. The survey instrument will operate in the J and H bands and will be as scientifically versatile and as easy to use as a large format CCD camera. It is expected to be ready for astronomical use by late 1997. It will be particularly well-suited for surveys of star-forming regions, low mass stars, distant galaxies, clusters and QSOs. The camera will be commissioned at the prime focus of the 2.5 m Isaac Newton telescope, where the image scale is 0.45'/pixel, giving an effective field of view of 14.6 by 14.6 arc minutes. The field of view of this camera with 0.15' pixels is 5.1 by 5.1 arc minutes and is thus approximately 60 times larger than the current near-infrared imager on Keck (NIRC). When combined with a 4.0 m class telescope, the combination is approximately 10 times as powerful as the Keck 10.0 m, when the apertures are taken into account. The options for upgrading the camera into a wide field spectroscopic survey instrument are currently being investigated.© (1997) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.