High-resolution (6") surface densities in a Cygnus X sub-field (DR21), derived from the Herschel Space Observatory images observed within the HOBYS key project (Motte et al. 2010).
This page highlights a new method, called getsf, for extracting sources and filaments in astronomical images using separation of their structural components. The method is universal, not limited to any particular area of astronomical research. It is specifically designed to handle multi-wavelength sets of images and extremely complex filamentary backgrounds. The code is freely downloadable from its webpage (http://irfu.cea.fr/getsf/).
The main processing steps of getsf are:
(1) preparation of a complete set of images and derivation of high-resolution surface densities,
(2) separation of the structural components of sources, filaments, and backgrounds,
(3) flattening of the residual noise and background fluctuations for sources and filaments,
(4) combination of the components of sources and filaments over several wavebands,
(5) detection of sources and filaments in the wavelength-combined images,
(6) measurements of the physical properties of the detected sources and filaments.
The getsf method is fully automated, with a single user-definable free parameter: the maximum size of the structures of interest to extract. Its internal parameters have been calibrated and verified in numerous tests using various images (both simulated and observed ones) to make sure that it works well in all cases. It provides superior extraction qualities over the older methods: getsources (Men'shchikov et al. 2012), getfilaments (Men'shchikov 2013), and getimages (Men'shchikov 2017).