학술논문
On-sky performance of the CLASS Q-band telescope
Document Type
Working Paper
Author
Appel, John W.; Xu, Zhilei; Padilla, Ivan L.; Harrington, Kathleen; Marquez, Bastián Pradenas; Ali, Aamir; Bennett, Charles L.; Brewer, Michael K.; Bustos, Ricardo; Chan, Manwei; Chuss, David T.; Cleary, Joseph; Couto, Jullianna; Dahal, Sumit; Denis, Kevin; Dünner, Rolando; Eimer, Joseph R.; Essinger-Hileman, Thomas; Fluxa, Pedro; Gothe, Dominik; Hilton, Gene C.; Hubmayr, Johannes; Iuliano, Jeffrey; Karakla, John; Marriage, Tobias A.; Miller, Nathan J.; Núñez, Carolina; Parker, Lucas; Petroff, Matthew; Reintsema, Carl D.; Rostem, Karwan; Stevens, Robert W.; Valle, Deniz Augusto Nunes; Wang, Bingjie; Watts, Duncan J.; Wollack, Edward J.; Zeng, Lingzhen
Source
Subject
Language
Abstract
The Cosmology Large Angular Scale Surveyor (CLASS) is mapping the polarization of the Cosmic Microwave Background (CMB) at large angular scales ($2<\ell\lesssim200$) in search of a primordial gravitational wave B-mode signal down to a tensor-to-scalar ratio of $r \approx 0.01$. The same data set will provide a near sample-variance-limited measurement of the optical depth to reionization. Between June 2016 and March 2018, CLASS completed the largest ground-based Q-band CMB survey to date, covering over 31 000~square-degrees (75% of the sky), with an instantaneous array noise-equivalent temperature (NET) sensitivity of $32~\mu \mbox{K}_{cmb}\sqrt{\mbox{s}}$. We demonstrate that the detector optical loading ($1.6~\mbox{pW}$) and noise-equivalent power ($19~\mbox{aW}\sqrt{\mbox{s}}$) match the expected noise model dominated by photon bunching noise. We derive a $13.1\pm0.3~\mbox{K/pW}$ calibration to antenna temperature based on Moon observations, which translates to an optical efficiency of $0.48\pm0.04$ and a $27~\mbox{K}$ system noise temperature. Finally, we report a Tau A flux density of $308\pm11~\mbox{Jy}$ at $38.4\pm0.2~\mbox{GHz}$, consistent with the WMAP Tau A time-dependent spectral flux density model.
Comment: 11 pages, 5 figures
Comment: 11 pages, 5 figures