Initial Results from the USNO Dispersed Fourier Transform Spectrograph

• Main Authors: Hajian, Arsen R, Behr, Bradford B, Cenko, Andrew T, Olling, Robert P, Mozurkewich, David, Armstrong, J. Thomas, Pohl, Brian, Petrossian, Sevan, Knuth, Kevin H, Hindsley, Robert B, Murison, Marc, Efroimsky, Michael, Dantowitz, Ronald, Kozubal, Marek, Currie, Douglas G, Nordgren, Tyler E, Tycner, Christopher, McMillan, Robert S
• Format: Journal Article
• Language: English
• Published: 15.11.2006
• Subjects: Physics - Astrophysics of Galaxies; Physics - Cosmology and Nongalactic Astrophysics; Physics - Earth and Planetary Astrophysics; Physics - High Energy Astrophysical Phenomena; Physics - Instrumentation and Methods for Astrophysics; Physics - Solar and Stellar Astrophysics
• DOI: 10.48550/arxiv.astro-ph/0611495

Astrophys.J.661:616-633,2007 We have designed and constructed a ``dispersed Fourier Transform Spectrometer'' (dFTS), consisting of a conventional FTS followed by a grating spectrometer. By combining these two devices, we negate a substantial fraction of the sensitivity disadvantage of a conventional FTS for high resolution, broadband, optical spectroscopy, while preserving many of the advantages inherent to interferometric spectrometers. In addition, we have implemented a simple and inexpensive laser metrology system, which enables very precise calibration of the interferometer wavelength scale. The fusion of interferometric and dispersive technologies with a laser metrology system yields an instrument well-suited to stellar spectroscopy, velocimetry, and extrasolar planet detection, which is competitive with existing high-resolution, high accuracy stellar spectrometers. In this paper, we describe the design of our prototype dFTS, explain the algorithm we use to efficiently reconstruct a broadband spectrum from a sequence of narrowband interferograms, and present initial observations and resulting velocimetry of stellar targets.