Astrometric and Photometric Calibrators for the 4-m International Liquid Mirror Telescope
Kumar, Brajesh; Surdej, Jean; Negi, Vibhore; Hickson, Paul; Dukiya, Naveen; Misra, Kuntal; Ailawadhi, Bhavya; Grewal, Baldeep; Akhunov, Talat; Borra, Ermanno; Dubey, Monalisa; Fu, Jiuyang; Pranshu, Kumar; Sun, Ethen
Abstract
The International Liquid Mirror Telescope (ILMT) is a 4-meter class survey telescope. It achieved its first light on 29th April 2022 and is now undergoing the commissioning phase. It scans the sky in a fixed wide strip centred at the declination of and works in Time Delay Integration (TDI) mode. We present a full catalog of sources in the ILMT strip derived by crossmatching Gaia DR3 with SDSS DR17 and PanSTARRS-1 (PS1) to supplement the catalog with apparent magnitudes of these sources in g, r, and i filters. These sources can serve as astrometric calibrators. The release of Gaia DR3 provides synthetic photometry in popular broadband photometric systems, including the SDSS g, r, and i bands for ∼220 million sources across the sky. We have used this synthetic photometry to verify our crossmatching performance and, in turn, create a subset of the catalog with accurate photometric measurements from two reliable sources.