Aztica [arXiv:1711.08456] is an implementation of a blind source separation algorithm to remove foregrounds off millimeter surveys; it can benefit a lot from multi-frequency data but has the ability to work even with observations taken with single-channel instruments. Ground based millimeter observations face different challenges, starting with atmospheric contamination. But beyond the Earth's atmosphere, different layers of astrophysical emissions hinder distant extragalactic sources. In reality, an astrophysical map is a mixture of all those layers. The job of Aztica is to recognize and unmix signals of different statistical (and physical) origin, allowing the astronomer to analyze each emission separately. We have tested Aztica using mock extragalactic data: atmospheric fluctuations, extended astrophysical foregrounds, and sub-millimeter galaxies (SMGs). We also revisited the AzTEC/ASTE survey of the Great Observatories Origins Deep Survey-South (GOODS-S). In both applications, Aztica robustly decomposes maps into their underlying components, reducing flux bias, improving signal-to-noise, and minimizing information loss. In particular, the GOODS-S survey is decomposed into four independent physical components, one of them is the already known map of SMGs, two are atmospheric and systematic foregrounds, and the fourth component is an extended emission that we have interpreted as the confusion background of faint millimeter sources.
Enviado por ivrguez@gmail.com, 2019 Oct