HIRMES – HIgh Resolution Mid-infrarEd Spectrometer for SOFIA

Abstract

HIRMES is a third generation SOFIA instrument designed to cover the gap in the middle infrared region with a broad range of spectra resolution from very low (300-600) to high resolving power of 10⁵ . With its high resolving power modes (R from 50,000 to 100,000), HIRMES will provide unique access to HD in protoplanetary disks, and allows velocity resolved spectroscopy of water at temperatures characteristic of the snow line. HIRMES measures the velocities of orbiting gas in [OI] 63 µm line, one of the strongest fine structure lines, a tracer of spatial structure that is not available from direct imaging. HIRMES uses its grating mode (R ~ 600) to determine the mass of water ice in the system and to explore the crystalline mass fraction of the ice, providing information about its thermal evolution. HIRMES observations of the distribution of water ice, water vapor (including heavy isotopologues), and oxygen in planet-forming disks will illuminate the fossil record of these components in our own Solar System, as preserved in comets and asteroids. HIRMES is a direct photon detecting spectrometer, thus it achieves the sensitivity necessary to be in the discovery space which is fundamentally inaccessible to heterodyne receiver instruments. Hundreds of protoplanetary disks in associations within 500 parsecs of our Solar System, including well over 100 in the three nearest Young Stellar Object (YSO) associations 140-160 pc away, are within HIRMES grasp.