What is ROSALIA?

The primary mission of ROSALIA is to provide an estimate of the sky background level of an image obtained with a space telescope. Most researchers combine multiple images obtained with telescopes to generate deeper images (more precise). However, due to tiny - but noticeable - differences in the conditions of the observation (i.e., zodiacal light level, stray-light contamination, thermal background) the baseline level of the images (empty regions that we would expect to be zero) can present a certain level of light that must be removed. This is called sky background correction and it is one of the most critical steps in astronomical imaging.

Until now, most astronomers attempted to model and correct the background level using the science images themselves. However, this method has a number of problems associated, like sky background oversubtraction. ROSALIA takes a different approach: Use all the information available from other telescopes to predict the sky background level as a combination of stray-light, zodiacal light, and thermal background.