High Resolution Multi-Object Fiber-Fed Spectroscopy with Microwave Kinetic Inductance Detectors

University Of California-Santa Barbara, Santa Barbara CA

Investigators

Abstract

This project seeks to develop a new detector technology, called Microwave Kinetic Inductance Detectors (MKIDs), that would permit a spectrograph to be built that can take the spectra of many objects at the same time. An MKID detector also allows the color of all arriving light to be determined without the need for additional optics that result in some of the light being lost. This device has applications across and even beyond astronomy, from detecting life on planets around nearby stars to looking at the chemical compositions of stars in the Milky Way and nearby galaxies. Spectrographs with spectral resolution R>10,000 are one of the most important tools for nearly every discipline in astronomy, but design has been nearly static for the last several decades. A high-resolution spectrograph usually contains a collimator, echelle grating, cross disperser, and finally a camera and science detector. The 2-d nature of the resulting light (echellogram) makes use of long slits practical but prevents spectral coverage of more than about a single order at the high multiplex factors demanded by modern spectroscopic observations. This means that observations with these instruments are limited to medium or low (R<6,000) resolution, or very narrow spectral ranges at higher resolution, and this can preclude in depth chemical abundance analysis of the targets. This project proposes to build a testbed for new type of high-resolution multi-object spectrograph (HRMOS) using Microwave Kinetic Inductance Detectors, or MKIDs. MKIDs can determine the energy of each arriving photon without added read noise or dark current, and with microsecond temporal resolution. The wavelength discrimination of photons enabled by using MKID detectors removes the need of the optical cross disperser allowing the resulting echelle spectrograph to have a considerably simpler optical design. It allows the simultaneous measurement of the full echellogram of the output of many fibers using a series of parallel linear strips of MKIDs. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.