UVIT data release version 7: Regenerated high-level UVIT data products

Abstract

Ultra-Violet Imaging Telescope (UVIT) on board AstroSat is an active telescope capable of highresolution far-ultraviolet imaging (<1.5) and low-resolution (λ/δλ ≈ 100) slitless spectroscopy with a fieldof-view as large as ∼ 0.5◦. Now almost a decade old, UVIT continues to be operational and generates valuable data for the scientific community. UVIT is also capable of near-ultraviolet imaging (<1.5); however, the nearultraviolet channel stopped working in August 2018 after providing data for nearly 3 years. This paper gives an overview of the latest version (7.0.1) of the UVIT pipeline and UVIT data release version 7. The high-level products generated using pipeline versions having a major ver. no. 7 will be called ‘UVIT data release version 7’. The latest pipeline version overcomes two limitations of the previous version (6.3), namely: (a) inability to combine all episode-wise images; and (b) failure of the astrometry module in a large fraction of the observations. The procedures adopted to overcome these two limitations as well as a comparison of the performance of this new version over the previous one, are presented in this paper. The UVIT data release version 7 products are available at the Indian Space Science Data Center of the Indian Space Research Organization for archival and dissemination from 1 June 2024. New pipeline version is open source and made available on GitHub