Auto-Guiding System for CQUEAN (Camera for QUasars in EArly uNiverse)

TL;DR

This paper presents an auto-guiding system for the CQUEAN camera, enabling stable long-exposure imaging of red objects like high-redshift quasars and brown dwarfs by increasing guiding star availability and system stability.

Contribution

Development of a novel auto-guiding system with a rotating guiding camera mechanism for the CQUEAN instrument, enhancing long-exposure imaging capabilities.

Findings

Achieved stable 1200-second exposures with the system.

Successfully increased guiding star availability via a rotating mechanism.

Confirmed system stability through observational tests.

Abstract

To perform imaging observation of optically red objects such as high redshift quasars and brown dwarfs, the Center for the Exploration of the Origin of the Universe (CEOU) recently developed an optical CCD camera, Camera for QUasars in EArly uNiverse(CQUEAN), which is sensitive at 0.7-1.1 um. To enable observations with long exposures, we developed an auto-guiding system for CQUEAN. This system consists of an off-axis mirror, a baffle, a CCD camera, a motor and a differential decelerator. To increase the number of available guiding stars, we designed a rotating mechanism for the off-axis guiding camera. The guiding field can be scanned along the 10 acrmin ring offset from the optical axis of the telescope. Combined with the auto-guiding software of the McDonald Observatory, we confirmed that a stable image can be obtained with an exposure time as long as 1200 seconds.