title: Dispersed single-phase-step Michelson interferometer for Doppler imaging using sunlight.
abstract: A Michelson interferometer is dispersed with a fiber array-fed spectrograph, providing 59 Doppler sensing channels using sunlight in the 510-570 nm wavelength region. The interferometer operates at a single-phase-step mode, which is particularly advantageous in multiplexing and data processing compared to the phase-stepping mode of other interferometer spectrometer instruments. Spectral templates are prepared using a standard solar spectrum and simulated interferometer modulations, such that the correlation function with a measured 1D spectrum determines the Doppler shift. Doppler imaging of a rotating cylinder is demonstrated. The average Doppler sensitivity is ~12 m/s, with some channels reaching ~5 m/s.
authors.affiliation: Department of Astronomy, University of Florida, Gainesville, Florida 32611, USA. xwan@astro.ufl.edu
authors.forename: Xiaoke
authors.initials: X
authors.lastname: Wan
authors.forename: Jian
authors.initials: J
authors.lastname: Ge