Michelle Creech-Eakman, New Mexico Tech/MRO Interferometer; Van Romero, NMT; Chris Haniff, University of Cambridge; David Buscher, University of Cambridge; John Young, University of Cambridge; Chris Salcido, New Mexico Tech/MRO Interferometer
Keywords: long-baseline optical interferometry, high-resolution imaging, astronomical interferometer
Abstract:
The Magdalena Ridge Observatory Interferometer (MROI) was initially proposed as an ambitious, long-baseline optical/near-infrared astronomical imaging interferometer in the early 2000s. Today, it is being developed through a collaboration between New Mexico Tech and researchers and faculty at Cambridge University in the UK and funded by the Air Force Research Lab via a Cooperative Agreement with the university. When completed, MROI will be comprised of ten 1.4m aperture telescopes distributed in an equilateral-Y configuration at 10,500 feet altitude in the mountains of central New Mexico. The telescopes are used in coordination with each other, moved across 28 stations, allowing for baselines ranging from 7.8 to 343 meters. At the observing wavelengths in the optical and near-infrared, this translates to angular resolutions of 40 milliarcseconds down to 0.5 milliarcseconds. The telescopes are being built by AMOS in Belgium and are an alt-alt design, decreasing the number of reflections before injecting the collected light into the beam transport system. The enclosures are being built by EIE in Italy and both protect and are used to transport the telescopes between stations. The beam transport is all accomplished in vacuum with active optical systems for beam steering. Delay compensation is done using custom delay carts being developed and built by Cambridge University. The beam combining facilities, completed nearly a decade ago, are built to support the full 10-telescope facility while minimizing vibrations, temperature excursions, and presenting a polarization preserving approach to beam transport and sensing. The beam combining activities are conducted in open air at near-infrared wavelengths for fringe sensing, and optical and near-infrared for scientific measurements. They employ new photon counting infrared detectors for both fringe tracking and science using custom developed infrared cryostats built by Universal Cryogenics in Arizona.
A key science program has been developed from which all design choices for the facility flow-down. The key science mission includes: 1) young stars and the earliest phases of planet formation, 2) ubiquitous topics of stellar astrophysics centered on binary systems, mass loss/transfer, and time-varying phenomena such as pulsation and convection, and finally, 3) the immediate surroundings of active galactic nuclei (AGN) in nearby galaxies. MROIs anticipated sensitivity, closure phase precision and angular resolution needed for this ambitious astrophysics program is also uniquely useful for questions in space domain awareness (SDA).
We will present an overview of the optical layout of the facility, a description of the function and current state of all major subsystems, and a brief look at the aspirational astrophysics capabilities for the key science program. Special emphasis on the next few years activities, including initial demonstrations of sensitivity, closure phase precision, and visibilities on shorter baselines ( < 4 0m) will also be presented. Date of Conference: September 27-20, 2022
Track: Optical Systems & Instrumentation