Astrometric and Photometric Standard Candidates for the Upcoming 4-m International Liquid Mirror Telescope Survey
Abstract
The International Liquid Mirror Telescope (ILMT) is a 4-m class survey telescope that has recently achieved first light and is expected to swing into full operations by January 1, 2023. It scans the sky in a fixed 22′ wide strip centered at the declination of 29∘21′41′′ and works in Time Delay Integration (TDI) mode. We present a full catalog of sources in the ILMT strip that can serve as astrometric calibrators. The characteristics of the sources for astrometric calibration are extracted from Gaia EDR3 as it provides a very precise measurement of astrometric properties such as RA (α), Dec (δ), parallax (π), and proper motions (μα∗ & μδ). We have crossmatched the Gaia EDR3 with SDSS DR17 and PanSTARRS-1 (PS1) and supplemented the catalog with apparent magnitudes of these sources in g,r, and i filters. We also present a catalog of spectroscopically confirmed white dwarfs with Sloan Digital Sky Survey (SDSS) magnitudes that may serve as photometric calibrators. The catalogs generated are stored in an SQLite database for query-based access. We also report the offsets in equatorial positions compared to Gaia for an astrometrically calibrated TDI frame observed with the ILMT.
- Publication:
-
Journal of Astronomical Instrumentation
- Pub Date:
- 2022
- DOI:
- 10.1142/S2251171722400013
- arXiv:
- arXiv:2210.06473
- Bibcode:
- 2022JAI....1140001D
- Keywords:
-
- Liquid mirror telescope;
- survey;
- crossmatching;
- astrometry;
- photometry;
- Astrophysics - Instrumentation and Methods for Astrophysics;
- Astrophysics - Solar and Stellar Astrophysics
- E-Print:
- Accepted for Publication in Journal of Astronomical Instrumentation