Potential UV standards for UVIT filter system

摘要

We propose a set of eleven faint UV white dwarf stars as potential UV standards for the UVIT filter system on-board AstroSat mission. Synthetic photometry of these stars has been carried out using the in-orbit filter curves of UVIT, GALEX, UVOT and model spectra in the literature. The synthetic photometry of GALEX and UVOT is well correlated with their respective observations. The synthetic UVIT photometry is found to be strongly correlated with that of GALEX. The UV extinction A(lambda) for these stars has been computed using CCM-89 extinction model and its value for the lambda of each UVIT filter band has been listed. These results motivate us to recommend this set of stars as additional UVIT flux calibrators.