Jan 28, 2015
B. Mason (NRAO), S. Dicker, S. Stanchfield & M. Devlin (U. Penn)
The MUSTANG-2 array of 223 feed horns, which are machined out of a single aluminum block that has been gold-coated. Dual-polarization detector modules are affixed to each feed.
In December 2014, a new bolometer camera (MUSTANG-2) was installed on the NRAO Green Bank Telescope (GBT). This camera employs many of the technologies used in its predecessor – MUSTANG, used by GBT observers from 2009 to 2013 – including Transition Edge Sensor (TES) bolometers; Superconducting QUantum Interference Device (SQUID) amplifiers to read out the detectors; a low-vibration pulse tube refrigerator; and closed-cycle helium-3 and helium-4 refrigerators to cool the detectors to 300 mK.
MUSTANG-2 features many improvements: more sensitive microstrip- and feedhorn-coupled TES bolometers; a wider (75-105 GHz) band pass; a 5x larger instantaneous field-of-view; and much more robust cryogenic performance. Readout is accomplished via four ROACH boards using a microwave-resonator multiplexer that has been adapted for use with TES detectors. The receiver has been designed to accommodate 223 dual-polarization detectors, and the full 223 feedhorn detector array has been fabricated and deployed on the GBT (Figure 1). Available funding permitted populating only 64 of the 223 feeds; the current version of the instrument has thus been dubbed MUSTANG-1.5.
Similar to its predecessor, MUSTANG-2 will have a ~8.5″ (FWHM) beam when used on the GBT. It is available for early science observing in collaboration with the instrument team. Commissioning is ongoing and we expect that early science observing will begin in late January 2015. MUSTANG-2 will excel at making high-resolution images of the Sunyaev-Zel’dovich effect, and mapping the large-scale context of star formation in our own Galaxy and nearby galaxies.
See the full article here.
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The NRAO operates a complementary, state-of-the-art suite of radio telescope facilities for use by the scientific community, regardless of institutional or national affiliation: the Very Large Array (VLA), the Robert C. Byrd Green Bank Telescope (GBT), and the Very Long Baseline Array (VLBA)*.
The NRAO is building two new major research facilities in partnership with the international community that will soon open new scientific frontiers: the Atacama Large Millimeter/submillimeter Array (ALMA), and the Expanded Very Large Array (EVLA). Access to ALMA observing time by the North American astronomical community will be through the North American ALMA Science Center (NAASC).
*The Very Long Baseline Array (VLBA) comprises ten radio telescopes spanning 5,351 miles. It’s the world’s largest, sharpest, dedicated telescope array. With an eye this sharp, you could be in Los Angeles and clearly read a street sign in New York City!
Astronomers use the continent-sized VLBA to zoom in on objects that shine brightly in radio waves, long-wavelength light that’s well below infrared on the spectrum. They observe blazars, quasars, black holes, and stars in every stage of the stellar life cycle. They plot pulsars, exoplanets, and masers, and track asteroids and planets.