4K$\times$4K CCD Imager for the 3.6m DOT: Recent up-gradations and results

TL;DR

This paper discusses recent upgrades to the 4Kx4K CCD Imager on the 3.6m DOT, highlighting improvements, calibration, and new scientific observations of faint sources and galaxy clusters since 2015.

Contribution

It reports recent hardware upgrades and new scientific applications enabled by the CCD Imager on the 3.6m DOT.

Findings

Successful implementation of new filter wheel and stray light baffles

Improved calibration and fringe correction in red filters

New observations of faint point sources and low surface brightness galaxies

Abstract

The 4K$\times$4K CCD Imager is the first light instrument for the 3.6m Devasthal Optical Telescope and is producing broad-band imaging observations of many Galactic and extra-galactic sources since 2015-2016. Capabilities of the CCD Imager are demonstrated recently through several publications using the well-calibrated multi-band deep photometric results as expected from other similar facilities globally. In this article, we summarize some of the recent up-gradations made to improve the Imager, i.e., mounting the new filter wheel casing, replacing stray light baffles and discussing the fringe pattern corrections in redder filters. Some of the new science initiatives like galaxy-embedded faint point sources including WR stars and the observations of low surface brightness galaxy clusters are also discussed.