on the sky is achieved using a fast Faraday rotation polarization switch and a wire-grid to interchange the reflected and transmitted beams to each receiver. This ultra-wide-band receiver typically achieves noise temperatures < 50K between 75 and 110 GHz. The Redshift Search Receiver has exceptional baseline stability because it does not involve mechanical moving parts, therefore being well-suited to the detection of redshifted transitions of the CO ladder from star-forming galaxies at cosmological distances. An innovative wide-band analog autocorrelator system which covers the full 38 GHz with 31 MHz (100 km/s at 90 GHz) resolution serves as the backed spectrometer. Decommissioned AzTEC The AzTEC millimetre camera was developed to operate at 1.1mm. It is formed by a 144 silicon nitride micromesh bolometer array arranged in a compact hexagonal package and fed by an array of horns separated by 1.4 fλ. The detectors are cooled down to ~250 mK inside a 3He closed-cycle cryostat, achieving a ~3 mJy Hz-1/2 pixel sensibility. The AzTEC field of view at the LMT is 2.4 arcminutes square and manages to take completely sampled images through telescope or reflecting secondary surface movements. References External links Instituto Nacional de Astrofísica, Óptica y Electrónica University of Massachusetts Astronomy Department TolTEC instrument website National Science Foundation (NSF) Radio telescopes Astronomical observatories in Mexico Buildings and structures in Puebla Trans-Mexican Volcanic Belt