The Atacama Cosmology Telescope: CMB polarization at 200 < ℓ < 9000
- Sub-Department of Astrophysics, University of Oxford, Keble Road, Oxford OX1 3RH (United Kingdom)
- Department of Astrophysical Sciences, Peyton Hall, Princeton University, Princeton, NJ 08544 (United States)
- Department of Physics, University of Michigan, Ann Arbor 48103 (United States)
- Department of Physics, Cornell University, Ithaca, NY 14853 (United States)
- Department of Physics and Astronomy, University of British Columbia, Vancouver, BC V6T 1Z4 (Canada)
- School of Physics and Astronomy, Cardiff University, The Parade, Cardiff, Wales CF24 3AA (United Kingdom)
- McWilliams Center for Cosmology, Carnegie Mellon University, Department of Physics, 5000 Forbes Ave., Pittsburgh PA 15213 (United States)
- NIST Quantum Devices Group, 325 Broadway Mailcode 817.03, Boulder, CO 80305 (United States)
- Canadian Institute for Theoretical Astrophysics, University of Toronto, Toronto, ON M5S 3H8 (Canada)
- Dept. of Physics and Astronomy, The Johns Hopkins University, 3400 N. Charles St., Baltimore, MD 21218-2686 (United States)
- Department of High Energy Physics, Argonne National Laboratory, 9700 S Cass Ave, Lemont, IL 60439 (United States)
We report on measurements of the cosmic microwave background (CMB) and celestial polarization at 146 GHz made with the Atacama Cosmology Telescope Polarimeter (ACTPol) in its first three months of observing. Four regions of sky covering a total of 270 square degrees were mapped with an angular resolution of 1.3'. The map noise levels in the four regions are between 11 and 17 μK-arcmin. We present TT, TE, EE, TB, EB, and BB power spectra from three of these regions. The observed E-mode polarization power spectrum, displaying six acoustic peaks in the range 200 < ℓ < 3000, is an excellent fit to the prediction of the best-fit cosmological models from WMAP9+ACT and Planck data. The polarization power spectrum, which mainly reflects primordial plasma velocity perturbations, provides an independent determination of cosmological parameters consistent with those based on the temperature power spectrum, which results mostly from primordial density perturbations. We find that without masking any point sources in the EE data at ℓ < 9000, the Poisson tail of the EE power spectrum due to polarized point sources has an amplitude less than 2.4 μ {sup 2} at ℓ = 3000 at 95% confidence. Finally, we report that the Crab Nebula, an important polarization calibration source at microwave frequencies, has 8.7% polarization with an angle of 150.7{sup o} ± 0.6{sup o} when smoothed with a 5' Gaussian beam.
- OSTI ID:
- 22375848
- Journal Information:
- Journal of Cosmology and Astroparticle Physics, Vol. 2014, Issue 10; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 1475-7516
- Country of Publication:
- United States
- Language:
- English
Similar Records
A Measurement of the CMB E-mode Angular Power Spectrum at Subdegree Scales from 670 Square Degrees of POLARBEAR Data
The Atacama Cosmology Telescope: Two-season ACTPol spectra and parameters