A template of atmospheric molecular oxygen circularly polarized emission for CMB experiments

• Main Authors: Fabbian, Giulio, Spinelli, Sebastiano, Gervasi, Massimo, Tartari, Andrea, Zannoni, Mario
• Format: Report
• Language: unknown
• Published: arXiv 2012
• Subjects: Cosmology and Nongalactic Astrophysics astro-ph.CO; Instrumentation and Methods for Astrophysics astro-ph.IM; Atmospheric and Oceanic Physics physics.ao-ph; FOS Physical sciences; South Pole; Antarc*; Antarctica; South pole
• Online Access: https://dx.doi.org/10.48550/arxiv.1206.0481; https://arxiv.org/abs/1206.0481

We compute the polarized signal from atmospheric molecular oxygen due to Zeeman effect in the Earth magnetic field for various sites suitable for CMB measurements such as South Pole, Dome C (Antarctica) and Atacama desert (Chile). We present maps of this signal for those sites and show their typical elevation and azimuth dependencies. We find a typical circularly polarized signal (V Stokes parameter) level of 50 - 300 μK at 90 GHz when looking at the zenith; Atacama site shows the lowest emission while Dome C site presents the lowest gradient in polarized brightness temperature (0.3 μK/deg at 90 GHz). The accuracy and robustness of the template are tested with respect to actual knowledge of the Earth magnetic field, its variability and atmospheric parameters. : To appear in the proceeding of 47th Rencontres de Moriond