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Far Sidelobe Effects from Panel Gaps of the Atacama Cosmology TelescopeThe Atacama Cosmology Telescope is a 6 meter diameter CMB telescope located at 5200 meters in the Chilean desert. ACT has made arc-minute scale maps of the sky at 90 and 150 GHz which have led to precise measurements of the fine angular power spectrum of the CMB fluctuations in temperature and polarization. One of the goals of ACT is to search for the B-mode polarization signal from primordial gravity waves, and thus extending ACT's data analysis to larger angular scales. This goal introduces new challenges in the control of systematic effects, including better understanding of far sidelobe effects that might enter the power spectrum at degree angular scales. Here we study the effects of the gaps between panels of the ACT primary and secondary reflectors in the worst case scenario in which the gaps remain open. We produced numerical simulations of the optics using GRASP up to 8 degrees away from the main beam and simulated timestreams for observations with this beam using real pointing information from ACT data. Maps from these simulated timestreams showed leakage from the sidelobes, indicating that this effect must be taken into consideration at large angular scales.
Document ID
20160010538
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Fluxa, Pedro R. (Catholic Univ. Santiago, Chile)
Duenner, Rolando (Catholic Univ. Santiago, Chile)
Maurin, Loiec (Catholic Univ. Santiago, Chile)
Choi, Steve K. (Princeton Univ. Princeton, NJ, United States)
Devlin, Mark J. (Pennsylvania Univ. Philadelphia, PA, United States)
Gallardo, Patricio A. (Cornell Univ. Ithaca, NY, United States)
Shuay-Pwu, P. Ho (Princeton Univ. Princeton, NJ, United States)
Koopman, Brian J. (Cornell Univ. Ithaca, NY, United States)
Louis, Thibaut (Oxford Univ. Oxford, United Kingdom)
Wollack, Edward J. (NASA Goddard Space Flight Center Greenbelt, MD United States)
Date Acquired
August 23, 2016
Publication Date
July 19, 2016
Publication Information
Publication: Proceedings of SPIE: Millimeter, Submillimeter, and Far-Infrared Detectors and Instrumentation for Astronomy VIII
Volume: 9914
Subject Category
Optics
Astronomy
Report/Patent Number
GSFC-E-DAA-TN35080
Meeting Information
Millimeter, Submillimeter, and Far-Infrared Detectors and Instrumentation for Astronomy(Edinburgh)
Funding Number(s)
CONTRACT_GRANT: ACT-1417
CONTRACT_GRANT: BASAL-PFB06
OTHER: ALMA-CONICYT-31140004
CONTRACT_GRANT: FONDECYT-1141113
Distribution Limits
Public
Copyright
Other
Keywords
The Atacama Cosmology Telescope
far sidelobe effects
simulated timestreams