Planck CO revisited: Improved CO line-emission maps from Planck space-mission observations

Abstract

The Planck space mission has observed the first three rotational lines of emission of Galactic carbon monoxide (CO). Those maps, however, are either noisy or contaminated by astrophysical emissions from different origin. We revisit those data products to deliver new full-sky CO maps with low astrophysical contamination and significantly enhanced noise properties. To that effect, a specific pipeline is designed to evaluate and postprocess the existing Planck Galactic CO maps. Specifically, we use an extension of the generalized needlet Internal Linear Combination method to extract multicomponent astrophysical emissions from multifrequency observations. Well-characterized, clean, CO full-sky maps at 10′ angular resolution are produced. These maps are made available to the scientific community and can be used to trace CO emission over the entire sky and to generate sky simulations in preparation for future cosmic microwave background (CMB) observations.