77 research outputs found
B-mode Detection with an Extended Planck Mission
The Planck satellite has a nominal mission lifetime of 14 months allowing two
complete surveys of the sky. Here we investigate the potential of an extended
Planck mission of four sky surveys to constrain primordial B-mode anisotropies
in the presence of dominant Galactic polarized foreground emission. An extended
Planck mission is capable of powerful constraints on primordial B-modes at low
multipoles, which cannot be probed by ground based or sub-orbital experiments.
A tensor-scalar ratio of r=0.05 can be detected at a high significance level by
an extended Planck mission and it should be possible to set a 95% upper limit
on r of 0.03 if the tensor-scalar ratio is vanishingly small. Furthermore,
extending the Planck mission to four sky surveys offers better control of
polarized Galactic dust emission, since the 217 GHz frequency band can be used
as an effective dust template in addition to the 353 GHz channel.Comment: 10 pages, 3 figure
The Primordial Inflation Explorer (PIXIE): A Nulling Polarimeter for Cosmic Microwave Background Observations
The Primordial Inflation Explorer (PIXIE) is an Explorer-class mission to
measure the gravity-wave signature of primordial inflation through its
distinctive imprint on the linear polarization of the cosmic microwave
background. The instrument consists of a polarizing Michelson interferometer
configured as a nulling polarimeter to measure the difference spectrum between
orthogonal linear polarizations from two co-aligned beams. Either input can
view the sky or a temperature-controlled absolute reference blackbody
calibrator. PIXIE will map the absolute intensity and linear polarization
(Stokes I, Q, and U parameters) over the full sky in 400 spectral channels
spanning 2.5 decades in frequency from 30 GHz to 6 THz (1 cm to 50 um
wavelength). Multi-moded optics provide background-limited sensitivity using
only 4 detectors, while the highly symmetric design and multiple signal
modulations provide robust rejection of potential systematic errors. The
principal science goal is the detection and characterization of linear
polarization from an inflationary epoch in the early universe, with
tensor-to-scalar ratio r < 10^{-3} at 5 standard deviations. The rich PIXIE
data set will also constrain physical processes ranging from Big Bang cosmology
to the nature of the first stars to physical conditions within the interstellar
medium of the Galaxy.Comment: 37 pages including 17 figures. Submitted to the Journal of Cosmology
and Astroparticle Physic
Planck 2015 results. XXVII. The Second Planck Catalogue of Sunyaev-Zeldovich Sources
We present the all-sky Planck catalogue of Sunyaev-Zeldovich (SZ) sources detected from the 29 month full-mission data. The catalogue (PSZ2) is the largest SZ-selected sample of galaxy clusters yet produced and the deepest all-sky catalogue of galaxy clusters. It contains 1653 detections, of which 1203 are confirmed clusters with identified counterparts in external data-sets, and is the first SZ-selected cluster survey containing > confirmed clusters. We present a detailed analysis of the survey selection function in terms of its completeness and statistical reliability, placing a lower limit of 83% on the purity. Using simulations, we find that the Y5R500 estimates are robust to pressure-profile variation and beam systematics, but accurate conversion to Y500 requires. the use of prior information on the cluster extent. We describe the multi-wavelength search for counterparts in ancillary data, which makes use of radio, microwave, infra-red, optical and X-ray data-sets, and which places emphasis on the robustness of the counterpart match. We discuss the physical properties of the new sample and identify a population of low-redshift X-ray under- luminous clusters revealed by SZ selection. These objects appear in optical and SZ surveys with consistent properties for their mass, but are almost absent from ROSAT X-ray selected samples
Planck early results III : First assessment of the Low Frequency Instrument in-flight performance
Peer reviewe
Planck early results XI : Calibration of the local galaxy cluster Sunyaev-Zeldovich scaling relations
Peer reviewe
Planck early results XVII : Origin of the submillimetre excess dust emission in the Magellanic Clouds
Peer reviewe
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