TolTEC is a three-band imaging polarimeter for the Large Millimeter Telescope. Simultaneously observing with passbands at 1.1mm, 1.4mm and 2.0mm, TolTEC has diffraction-limited beams with FWHM of 5, 7, and 11 arcsec, respectively. Over the coming decade, TolTEC will perform a combination of PI-led and Open-access Legacy Survey projects. Herein we provide an overview of the instrument and give the first quantitative measures of its performance in the lab prior to shipping to the telescope in 2021.
The Large Millimeter Telescope Alfonso Serrano (LMT) is a 50m-diameter radio telescope for millimeter-wave astronomy. In this paper we describe a number of initiatives underway to upgrade the antenna systems and permit scientific observations during daylight hours. We summarize recent efforts to characterize the thermal gradients that occur within the LMT structure and to identify important modes of surface deformation. The mitigation program involves use of the LMT's active surface to counteract the effects of measured thermal gradients within the antenna structure. It also includes active measures such as the installation of a ventilation system in the antenna backup structure. Prospects for additional active metrology measurements of the antenna surface for real-time surface corrections are also discussed.
The Large Millimeter Telescope (LMT) Alfonso Serrano is a 50m-diameter single-dish radio telescope constructed at an altitude of 4600 meters on the summit of Volcan Sierra Negra, an extinct volcano in the Mexican state of Puebla. The LMT is a bi-national scientific collaboration between Mexico and the USA, led by the Instituto Nacional de Astrofisica, Optica y Electronica (INAOE) and the University of Massachusetts at Amherst. The telescope currently operates at wavelengths from 4mm to 1mm, and during the dry winter months the LMT site provides the highest levels of atmospheric transmission and potential future access to submillimeter observing windows. This paper describes the current status and scientific performance of the LMT, the suite of scientific instrumentation and future engineering upgrades that will optimize the optical efficiency of the telescope and increase its scientific productivity.
The Large Millimeter Telescope (LMT) Alfonso Serrano is a bi-national (Mexico and USA) telescope facility operated by the Instituto Nacional de Astrofisica, Optica y Electronica (INAOE) and the University of Massachusetts. The LMT is designed as a 50-m diameter single-dish millimeter-wavelength telescope that is optimized to conduct scientific observations at frequencies between ~70 and 350 GHz. The LMT is constructed on the summit of Sierra Negra at an altitude of 4600m in the Mexican state of Puebla. The site offers excellent mm-wavelength atmospheric transparency all-year round, and the opportunity to conduct submillimeter wavelength observations during the winter months. Following first-light observations in mid-2011, the LMT began regular scientific operations in 2014 with a shared-risk Early Science observing program using the inner 32-m diameter of the primary reflector with an active surface control system. The LMT has already performed successful VLBI observations at 3mm with the High Sensitivity Array and also at 1.3mm as part of the Event Horizon Telescope. Since early 2018 the LMT has begun full scientific operations as a 50-m diameter telescope, making the LMT 50-m the world´s largest single-dish telescope operating at 1.1mm. I will describe the current status of the telescope project, including the early scientific results from the LMT 50-m, as well the instrumentation development program, the plan to improve the overall performance of the telescope, and the on-going transition towards the formation of the LMT Observatory to support the scientific community in their use of the LMT to study the formation and evolution of structure at all cosmic epochs.