| Authors Affiliation: | 1 Sonika Pridi, Ananta C Pradhan National Institute of Technology, Rourkela -769008,India
2 Ranjan Kumar Physical Research Laboratory, Navrangpura, Ahmedabad - 380009, India
3 Divya Pandey Tartu Observatory, University of Tartu, Observatooriumi 1, Tõravere 61602, Estonia |
| Abstract: | The Ultraviolet Imaging Telescope (UVIT) onboard AstroSat observes pointed observations simultaneously in far-UV (FUV) and near-UV (NUV). It has observed around ~1800 observations, including stellar clusters, galaxies, and nebulae. We present UVIT DR1, the first release of the comprehensive catalog for the observations taken during the first two years of its launch. UVIT DR1 encompasses an area of ~58 square degrees in 291 fields. We use the CCDLAB pipeline to reduce the L1 data and source-extractor for source detection. UVIT DR1 provides photometric magnitudes measured using different procedures such as aperture (for three different apertures), Kron, Isophotal, and point-spread function techniques. We verify our catalog by cross-matching with GALEX and Gaia source catalogs. The FUV depth in the magnitude where most of the sources are detected is found to be 22.75, 22.25, 21.75, and 20.75 mag for CaF2, BaF2, Sapphire, and Silica, respectively, while for NUV, this ranges from 23.75, 20.75, 22.25, 21.25, and 20.25 mag for Silica15, NUVB15, NUVB13, NUVB4, and NUVN2 filters, respectively. There are 239,520 unique sources in the combined UVIT DR1, of which 70,488 sources have FUV magnitudes and 211,410 have NUV magnitudes. UVIT DR1 would further help in various multi-wavelength analyses of UV sources. |
