55 research outputs found
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, from the highest energies at the dawn of time through the growth of
structure to the present day. 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 semi-analytic projection tool,
targeted explicitly towards optimizing constraints on the tensor-to-scalar
ratio, , 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 semi-analytic
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 at greater than , or, in the
absence of a detection, of reaching an upper limit of at CL.Comment: 24 pages, 8 figures, 9 tables, submitted to ApJ. arXiv admin note:
text overlap with arXiv:1907.0447
CMB-S4: Forecasting Constraints on Primordial Gravitational Waves
Abstract: 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
Emission Factors from Aerial and Ground Measurements of Field and Laboratory Forest Burns in the Southeastern U.S.: PM<sub>2.5</sub>, Black and Brown Carbon, VOC, and PCDD/PCDF
Aerial-
and ground-sampled emissions from three prescribed forest
burns in the southeastern U.S. were compared to emissions from laboratory
open burn tests using biomass from the same locations. A comprehensive
array of emissions, including PM<sub>2.5</sub>, black carbon (BC),
brown carbon (BrC), carbon dioxide (CO<sub>2</sub>), volatile organic
compounds (VOCs), and polychlorinated dibenzo-<i>p</i>-dioxins
(PCDDs) and polychlorinated dibenzofurans (PCDFs) were sampled using
ground-based and aerostat-lofted platforms for determination of emission
factors. The PM<sub>2.5</sub> emission factors ranged from 14 to 47
g/kg biomass, up to three times higher than previously published studies.
The biomass type was the primary determinant of PM<sub>2.5</sub>,
rather than whether the emission sample was gathered from the laboratory
or the field and from aerial- or ground-based sampling. The BC and
BrC emission factors ranged from 1.2 to 2.1 g/kg biomass and 1.0 to
1.4 g/kg biomass, respectively. A decrease in BC and BrC emission
factors with decreased combustion efficiency was found from both field
and laboratory data. VOC emission factors increased with decreased
combustion efficiency. No apparent differences in averaged emission
factors were observed between the field and laboratory for BC, BrC,
and VOCs. The average PCDD/PCDF emission factors ranged from 0.06
to 4.6 ng TEQ/kg biomass
- …