Verification of the Optical System of the 9.7-m Prototype Schwarzschild-Couder Telescope

TL;DR

This paper reports the first on-axis performance verification of the innovative Schwarzschild-Couder optical system in a 9.7-meter Cherenkov telescope, demonstrating its potential for enhanced gamma-ray astronomy observations.

Contribution

It presents the first successful demonstration of the Schwarzschild-Couder optical system's on-axis performance in a ground-based gamma-ray telescope, showcasing its alignment and imaging capabilities.

Findings

Achieved on-axis performance verification of the dual mirror system.

Demonstrated potential for improved angular resolution and off-axis sensitivity.

Provided initial alignment procedures and point-spread-function results.

Abstract

For the first time in the history of ground-based $\gamma$-ray astronomy, the on-axis performance of the dual mirror, aspheric, aplanatic Schwarzschild-Couder optical system has been demonstrated in a $9.7$-m aperture imaging atmospheric Cherenkov telescope. The novel design of the prototype Schwarzschild-Couder Telescope (pSCT) is motivated by the need of the next-generation Cherenkov Telescope Array (CTA) observatory to have the ability to perform wide ($\geq 8^{\circ}$) field-of-view observations simultaneously with superior imaging of atmospheric cascades (resolution of $0.067^{\circ}$ per pixel or better). The pSCT design, if implemented in the CTA installation, has the potential to improve significantly both the $\gamma$-ray angular resolution and the off-axis sensitivity of the observatory, reaching nearly the theoretical limit of the technique and thereby making a major impact on the CTA observatory sky survey programs, follow-up observations of multi-messenger transients with poorly known initial localization, as well as on the spatially resolved spectroscopic studies of extended $\gamma$-ray sources. This contribution reports on the initial alignment procedures and point-spread-function results for the challenging segmented aspheric primary and secondary mirrors of the pSCT.