13 research outputs found
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The Simons Observatory: Science goals and forecasts
The Simons Observatory (SO) is a new cosmic microwave background experiment
being built on Cerro Toco in Chile, due to begin observations in the early
2020s. We describe the scientific goals of the experiment, motivate the design,
and forecast its performance. SO will measure the temperature and polarization
anisotropy of the cosmic microwave background in six frequency bands: 27, 39,
93, 145, 225 and 280 GHz. The initial configuration of SO will have three
small-aperture 0.5-m telescopes (SATs) and one large-aperture 6-m telescope
(LAT), with a total of 60,000 cryogenic bolometers. Our key science goals are
to characterize the primordial perturbations, measure the number of
relativistic species and the mass of neutrinos, test for deviations from a
cosmological constant, improve our understanding of galaxy evolution, and
constrain the duration of reionization. The SATs will target the largest
angular scales observable from Chile, mapping ~10% of the sky to a white noise
level of 2 K-arcmin in combined 93 and 145 GHz bands, to measure the
primordial tensor-to-scalar ratio, , at a target level of .
The LAT will map ~40% of the sky at arcminute angular resolution to an expected
white noise level of 6 K-arcmin in combined 93 and 145 GHz bands,
overlapping with the majority of the LSST sky region and partially with DESI.
With up to an order of magnitude lower polarization noise than maps from the
Planck satellite, the high-resolution sky maps will constrain cosmological
parameters derived from the damping tail, gravitational lensing of the
microwave background, the primordial bispectrum, and the thermal and kinematic
Sunyaev-Zel'dovich effects, and will aid in delensing the large-angle
polarization signal to measure the tensor-to-scalar ratio. The survey will also
provide a legacy catalog of 16,000 galaxy clusters and more than 20,000
extragalactic sources
The insect pathogenic bacterium Xenorhabdus innexi has attenuated virulence in multiple insect model hosts yet encodes a potent mosquitocidal toxin
Performance of Temperature-Related Weather Index for Agricultural Insurance of Three Main Crops in China
A sustainable model for pediatric oncology nursing education and capacity building in Latin American hospitals: Evolution and impact of a nurse educator network
Adjacent-possible ecological niche: growth of Lactobacillus species co-cultured with Escherichia coli in a synthetic minimal medium
Recommended from our members
The Simons Observatory: Science goals and forecasts
The Simons Observatory (SO) is a new cosmic microwave background experiment being built on Cerro Toco in Chile, due to begin observations in the early 2020s. We describe the scientific goals of the experiment, motivate the design, and forecast its performance. SO will measure the temperature and polarization anisotropy of the cosmic microwave background in six frequency bands centered at: 27, 39, 93, 145, 225 and 280 GHz. The initial configuration of SO will have three small-aperture 0.5-m telescopes and one large-aperture 6-m telescope, with a total of 60,000 cryogenic bolometers. Our key science goals are to characterize the primordial perturbations, measure the number of relativistic species and the mass of neutrinos, test for deviations from a cosmological constant, improve our understanding of galaxy evolution, and constrain the duration of reionization. The small aperture telescopes will target the largest angular scales observable from Chile, mapping 10% of the sky to a white noise level of 2 μK-arcmin in combined 93 and 145 GHz bands, to measure the primordial tensor-to-scalar ratio, r, at a target level of σ(r)=0.003. The large aperture telescope will map 40% of the sky at arcminute angular resolution to an expected white noise level of 6 μK-arcmin in combined 93 and 145 GHz bands, overlapping with the majority of the Large Synoptic Survey Telescope sky region and partially with the Dark Energy Spectroscopic Instrument. With up to an order of magnitude lower polarization noise than maps from the Planck satellite, the high-resolution sky maps will constrain cosmological parameters derived from the damping tail, gravitational lensing of the microwave background, the primordial bispectrum, and the thermal and kinematic Sunyaev-Zel'dovich effects, and will aid in delensing the large-angle polarization signal to measure the tensor-to-scalar ratio. The survey will also provide a legacy catalog of 16,000 galaxy clusters and more than 20,000 extragalactic sources
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CMB-S4: Forecasting Constraints on Primordial Gravitational Waves
CMB-S4 - the next-generation ground-based cosmic microwave background (CMB) experiment - is set to significantly advance the sensitivity of CMB measurements and enhance our understanding of the origin and evolution of the universe. Among the science cases pursued with CMB-S4, the quest for detecting primordial gravitational waves is a central driver of the experimental design. This work details the development of a forecasting framework that includes a power-spectrum-based semianalytic projection tool, targeted explicitly toward optimizing constraints on the tensor-to-scalar ratio, r, in the presence of Galactic foregrounds and gravitational lensing of the CMB. This framework is unique in its direct use of information from the achieved performance of current Stage 2-3 CMB experiments to robustly forecast the science reach of upcoming CMB-polarization endeavors. The methodology allows for rapid iteration over experimental configurations and offers a flexible way to optimize the design of future experiments, given a desired scientific goal. To form a closed-loop process, we couple this semianalytic tool with map-based validation studies, which allow for the injection of additional complexity and verification of our forecasts with several independent analysis methods. We document multiple rounds of forecasts for CMB-S4 using this process and the resulting establishment of the current reference design of the primordial gravitational-wave component of the Stage-4 experiment, optimized to achieve our science goals of detecting primordial gravitational waves for r > 0.003 at greater than 5σ, or in the absence of a detection, of reaching an upper limit of r < 0.001 at 95% CL