Measurement of Telescope Transmission Using a Collimated Beam Projector. (15th March 2023)

• Record Type: Journal Article
• Authors: Mondrik, Nicholas; Coughlin, Michael; Betoule, Marc; Bongard, Sébastien; Rice, Joseph P.; Shaw, Ping-Shine; Stubbs, Christopher W.; Woodward, John T.
• Is Part Of: Publications of the Astronomical Society of the Pacific. Volume 135:Number 1045(2023)
• Publication Date: 2023-03-15
• Subjects: Astronomy -- Periodicals; Astronomy; Periodicals; Periodicals; 520.5
• DOI: 10.1088/1538-3873/acbe1c
• Languages: English
• ISSNs: 0004-6280

Abstract

Abstract: With the increasingly large number of Type Ia supernova being detected by current-generation survey telescopes, and even more expected with the upcoming Rubin Observatory Legacy Survey of Space and Time, the precision of cosmological measurements will become limited by systematic uncertainties in flux calibration rather than statistical noise. One major source of systematic error in determining SNe Ia color evolution (needed for distance estimation) is uncertainty in telescope transmission, both within and between surveys. We introduce here the Collimated Beam Projector (CBP), which is meant to measure a telescope transmission with collimated light. The collimated beam more closely mimics a stellar wave front as compared to flat-field-based instruments, allowing for more precise handling of systematic errors such as those from ghosting and filter angle-of-incidence dependence. As a proof of concept, we present CBP measurements of the StarDICE prototype telescope, achieving a standard (1 σ ) uncertainty of 3% on average over the full wavelength range measured with a single beam illumination.