Abstract
The Herschel space telescope hosts two infrared photometers having an unprecedented resolution, sensitivity and dynamic range. The map making, i.e. the formation of sky images from the instruments’ data, is critical for the full exploitation of the satellite and is a difficult task, since the readouts are affected by several disturbances, most notably by correlated noise. An effective map making approach is based on generalized least squares (GLS). However, when applied to Herschel data this approach poses several challenges and requires a specific pre- and post-processing. In the paper, we describe these challenges and introduce a set of algorithms and procedures which successfully address the issues. We also describe the implementation of the procedures and how these are integrated into an image formation software called UNIMAP, which is the first GLS map maker capable of automatically producing quality Herschel images with manageable memory and complexity requirements.
Author
Piazzo, Lorenzo; Calzoletti, Luca; Faustini, Fabiana; Pestalozzi, Michele; Pezzuto, Stefano; Elia, Davide; di Giorgio, Anna; Molinari, Sergio
Journal
Monthly Notices of the Royal Astronomical Society: Letters
Paper Publication Date
February 2015
Paper Type
Astroinformatics