################## MUSTANG-2 Overview ################## MUSTANG-2 is a bolometer (continuum) camera with ~215 feedhorns and a bandpass from 75 to 105 GHz on the GBT. MUSTANG-2 is inherently a mapping instrument and observes by scanning “on-the-fly” (OTF). Our most common scan pattern is that of a Lissajous Daisy that can observe objects from our resolution (9″) to several arcminutes in size (more details on :ref:`mapping `). For scans of ~a degree, we have switched to a raster scan. If you would like to consider another mapping strategy, please contact a member of :ref:`the MUSTANG-2 instrument ` team to inquire about it. The instantaneous field of view (FOV) is just over 4 arcminutes (4.2′). For full bandpass details see :ref:`this page `. MUSTANG-2 was commissioned on the GBT in spring 2016 (see development :ref:`timeline `), and has been offered for observations on a shared risk basis, in collaboration with the instrument team, since the 2018A GBO proposal call. Several features distinguish it from its predecessor, MUSTANG: * A new, microstrip-coupled detector design yields higher sensitivity and less susceptibility to environmental microphonics. * Detectors are feedhorn coupled, with the sum of two linear polarizations measured by a single TES per feed. * The instantaneous field of view is 4 arcminutes (vs 42 arcseconds for MUSTANG) * The receiver design incorporates a tilted refrigerator and receiver rotator, resulting in much lower dependence of cooling performance on telescope elevation. * The detector readout is the first astronomical use of microwave resonators to multiplex TES bolometers. MUSTANG-2 has been developed by a collaboration including the University of Pennsylvania, NIST, NRAO, the University of Michigan, and Cardiff University. All critical MUSTANG-2 systems have already been proven in operation on the GBT in early 2015 during an engineering run using a partially populated version of the receiver (“MUSTANG-1.5”, which had 64 populated feed horns). Many :ref:`papers ` have been published using both MUSTANG and MUSTANG-2. Scientific Motivation for MUSTANG-2 and Future Upgrades ======================================================= See the `science cases for MUSTANG3 `__.