MIRAC-5: A ground-based mid-IR instrument with the potential to detect ammonia in gas giants

Abstract

We present the fifth incarnation of the Mid-Infrared Array Camera (MIRAC-5) instrument which will use a new GeoSnap (3 – 13 microns) detector. Advances in adaptive optics (AO) systems and detectors are enabling ground-based mid-infrared systems capable of high spatial resolution and deep contrast. As one of the only 3 – 13 micron cameras used in tandem with AO, MIRAC-5 will be complementary to the James Webb Space Telescope (JWST) and capable of characterizing gas giant exoplanets and imaging forming protoplanets (helping to characterize their circumplanetary disks). We describe key features of the MIRAC-5 GeoSnap detector, a long-wave Mercury-Cadmium-Telluride (MCT) array produced by Teledyne Imaging Sensors (TIS), including its high quantum efficiency (> 65%), large well-depth, and low noise. We summarize MIRAC-5’s important capabilities, including prospects for obtaining the first continuum mid-infrared measurements for several gas giants and the first 10.2-10.8 micron NH3 detection in the atmosphere of the warm companion GJ 504b (Teff ~ 550 K) within 8 hours of observing time. Finally, we describe plans for future upgrades to MIRAC-5 such as adding a coronagraph. MIRAC-5 will be commissioned on the MMT utilizing the new MAPS AO system in late 2022 with plans to move to Magellan with the MagAO system in the future. © 2022 SPIE.