Dr. Bustos-Placencia, Ricardo

2019, Appel, John W., Xu, Zhilei, Padilla, Ivan L., Harrington, Kathleen, Pradenas Marquez, Bastián, Ali, Aamir, Bennett, Charles L., Brewer, Michael K., Bustos-Placencia, Ricardo, Chan, Manwei, Chuss, David T., Cleary, Joseph, Couto, Jullianna Denes, 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., Nunes Valle, Deniz Augusto, Wang, Bingjie, Watts, Duncan J., Wollack, Edward J., Zeng, Lingzhen

The Cosmology Large Angular Scale Surveyor (CLASS) is mapping the polarization of the cosmic microwave background (CMB) at large angular scales (2 < ℓ lesssim 200) in search of a primordial gravitational wave B-mode signal down to a tensor-to-scalar ratio of r ≈ 0.01. The same data set will provide a near sample-variance-limited measurement of the optical depth to reionization. Between 2016 June and 2018 March, 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 sensitivity of $32\,\mu {{\rm{K}}}_{\mathrm{cmb}}\sqrt{{\rm{s}}}$. We demonstrate that the detector optical loading (1.6 pW) and noise-equivalent power (19 $\mathrm{aW}\sqrt{{\rm{s}}}$) match the expected noise model dominated by photon bunching noise. We derive a 13.1 ± 0.3 K pW−1 calibration to antenna temperature based on Moon observations, which translates to an optical efficiency of 0.48 ± 0.02 and a 27 K system noise temperature. Finally, we report a Tau A flux density of 308 ± 11 Jy at 38.4 ± 0.2 GHz, consistent with the Wilkinson Microwave Anisotropy Probe Tau A time-dependent spectral flux density model.