Large Millimeter Telescope

The Large Millimeter Telescope (LMT, aka Gran Telescopio Milimétrico, GTM) is a 50-meter diameter telescope at Volcan Sierra Negra, Mexico, aimed at wavelengths on the order of 1 mm, i.e., short microwave and long infrared wavelengths. It is situated at 4,640 metres (15200 feet) and detects 0.85 to 4 mm (75-350 GHz) signal. At its location, only part of the year provides ideal observation. It does not approach the angular resolution of Atacama Large Millimeter Array (ALMA) but features a much larger field of view. Its first light was in 2011, and went into operation in 2013 using the inner 32 m of the reflector, with 50 m becoming operational in 2017. Its angular resolution at 1.1 mm was 8.5 arcsec with the 32 m reflector and 5.5 arcsec with 50 m. The 50 m size gives it the ability to detect a star formation of 10 solar masses per year in galaxies at high redshift. Instruments include:

• SEQUOIA - 32 pixel, 3 mm camera.
• RSR - Redshift Search Receiver - 4 pixel camera covering the 90 GHz atmospheric window to detect redshift of carbon monoxide spectrum features.
• B4R - 2 mm receiver and spectrometer.
• MSIP1mm - single-pixel 1 mm receiver.
• TolTEC - a camera imaging simultaneously in three bands, for rapid surveying.

Past:

• AzTEC - 144 pixel 1.1 mm camera, replaced by TolTEC.

Future:

• OMAyA "One Millimeter Array for Astronomy".

LMT suffered an outage in August 2023, with expected resumption in January 2024, but as of February 2024, I'm not sure if that has occurred.