105 research outputs found
Subsidiarity and Proportionality in the Single Market: An EU fit for inclusive growth
This report offers a fresh perspective on the principles of subsidiarity and proportionality in the European Union based on a thorough-going economic analysis. Specifically, the report uses the EU Single Market as a case to discuss shortcomings and potential improvements in five key policy areas. It reviews how the principles of subsid- iarity and proportionality can help boost growth in the EU at the aggregate country level – while at the same time allowing EU regions to benefit from growth. The report focuses on the regional level as economic growth has been uneven across the EU’s regions over the last decade and, consequently, growing disparities between re- gions have emerged. This alone merits a review on how we can reconcile the twin objectives in the future
Simulated forecasts for primordial B-mode searches in ground-based experiments
Detecting the imprint of inflationary gravitational waves on the -mode
polarization of the Cosmic Microwave Background (CMB) is one of the main
science cases for current and next-generation CMB experiments. In this work we
explore some of the challenges that ground-based facilities will have to face
in order to carry out this measurement in the presence of Galactic foregrounds
and correlated atmospheric noise. We present forecasts for Stage-3 (S3) and
planned Stage-4 (S4) experiments based on the analysis of simulated sky maps
using a map-based Bayesian foreground cleaning method. Our results thus
consistently propagate the uncertainties on foreground parameters such as
spatially-varying spectral indices, as well as the bias on the measured
tensor-to-scalar ratio caused by an incorrect modelling of the foregrounds.
We find that S3 and S4-like experiments should be able to put constraints on
of the order and
respectively, assuming instrumental
systematic effects are under control. We further study deviations from the
fiducial foreground model, finding that, while the effects of a second
polarized dust component would be minimal on both S3 and S4, a 2\% polarized
anomalous dust emission (AME) component would be clearly detectable by Stage-4
experiments.Comment: 19 pages, 11 figure
The Atacama Cosmology Telescope: Galactic Dust Structure and the Cosmic PAH Background in Cross-correlation with WISE
We present a cross-correlation analysis between resolution total
intensity and polarization observations from the Atacama Cosmology Telescope
(ACT) at 150 and 220 GHz and 15 mid-infrared photometry from the Wide-field
Infrared Survey Explorer (WISE) over 107 12.512.5 patches
of sky. We detect a spatially isotropic signal in the WISEACT
cross power spectrum at 30 significance that we interpret as the
correlation between the cosmic infrared background at ACT frequencies and
polycyclic aromatic hydrocarbon (PAH) emission from galaxies in WISE, i.e., the
cosmic PAH background. Within the Milky Way, the Galactic dust spectra are
generally well-described by power laws in over the range 1010, but there is evidence both for variability in the power law index and
for non-power law behavior in some regions. We measure a positive correlation
between WISE total intensity and ACT -mode polarization at 10006000 at 3 in each of 35 distinct 100 deg regions
of the sky, suggesting alignment between Galactic density structures and the
local magnetic field persists to sub-parsec physical scales in these regions.
The distribution of amplitudes in this range across all 107 regions
is biased to positive values, while there is no evidence for such a bias in the
spectra. This work constitutes the highest- measurements of the
Galactic dust spectrum to date and indicates that cross-correlation with
high-resolution mid-infrared measurements of dust emission is a promising tool
for constraining the spatial statistics of dust emission at millimeter
wavelengths.Comment: 20 pages, 14 figures, submitted to Ap
The Atacama Cosmology Telescope: Two-Season ACTPol Lensing Power Spectrum
We report a measurement of the power spectrum of cosmic microwave background
(CMB) lensing from two seasons of Atacama Cosmology Telescope Polarimeter
(ACTPol) CMB data. The CMB lensing power spectrum is extracted from both
temperature and polarization data using quadratic estimators. We obtain results
that are consistent with the expectation from the best-fit Planck LCDM model
over a range of multipoles L=80-2100, with an amplitude of lensing A_lens =
1.06 +/- 0.15 (stat.) +/- 0.06 (sys.) relative to Planck. Our measurement of
the CMB lensing power spectrum gives sigma_8 Omega_m^0.25 = 0.643 +/- 0.054;
including baryon acoustic oscillation scale data, we constrain the amplitude of
density fluctuations to be sigma_8 = 0.831 +/- 0.053. We also update
constraints on the neutrino mass sum. We verify our lensing measurement with a
number of null tests and systematic checks, finding no evidence of significant
systematic errors. This measurement relies on a small fraction of the ACTPol
data already taken; more precise lensing results can therefore be expected from
the full ACTPol dataset.Comment: 17 pages, 11 figures, to be submitted to Physical Review
The Atacama Cosmology Telescope: Millimeter Observations of a Population of Asteroids or: ACTeroids
We present fluxes and light curves for a population of asteroids at
millimeter (mm) wavelengths, detected by the Atacama Cosmology Telescope (ACT)
over 18, 000 deg2 of the sky using data from 2017 to 2021. We utilize high
cadence maps, which can be used in searching for moving objects such as
asteroids and trans-Neptunian Objects (TNOs), as well as for studying
transients. We detect 160 asteroids with a signal-to-noise of at least 5 in at
least one of the ACT observing bands, which are centered near 90, 150, and 220
GHz. For each asteroid, we compare the ACT measured flux to predicted fluxes
from the Near Earth Asteroid Thermal Model (NEATM) fit to WISE data. We confirm
previous results that detected a deficit of flux at millimeter wavelengths.
Moreover, we report a spectral characteristic to this deficit, such that the
flux is relatively lower at 150 and 220 GHz than at 90 GHz. Additionally, we
find that the deficit in flux is greater for S-type asteroids than for C-type.Comment: 15 pages, 9 Figures, 4 Table
The Simons Observatory: Beam characterization for the Small Aperture Telescopes
We use time-domain simulations of Jupiter observations to test and develop a
beam reconstruction pipeline for the Simons Observatory Small Aperture
Telescopes. The method relies on a map maker that estimates and subtracts
correlated atmospheric noise and a beam fitting code designed to compensate for
the bias caused by the map maker. We test our reconstruction performance for
four different frequency bands against various algorithmic parameters,
atmospheric conditions and input beams. We additionally show the reconstruction
quality as function of the number of available observations and investigate how
different calibration strategies affect the beam uncertainty. For all of the
cases considered, we find good agreement between the fitted results and the
input beam model within a ~1.5% error for a multipole range l = 30 - 700.Comment: 22 pages, 21 figures, to be submitted to Ap
The Atacama Cosmology Telescope: Two-Season ACTPol Spectra and Parameters
We present the temperature and polarization angular power spectra measured by
the Atacama Cosmology Telescope Polarimeter (ACTPol). We analyze night-time
data collected during 2013-14 using two detector arrays at 149 GHz, from 548
deg of sky on the celestial equator. We use these spectra, and the spectra
measured with the MBAC camera on ACT from 2008-10, in combination with Planck
and WMAP data to estimate cosmological parameters from the temperature,
polarization, and temperature-polarization cross-correlations. We find the new
ACTPol data to be consistent with the LCDM model. The ACTPol
temperature-polarization cross-spectrum now provides stronger constraints on
multiple parameters than the ACTPol temperature spectrum, including the baryon
density, the acoustic peak angular scale, and the derived Hubble constant.
Adding the new data to planck temperature data tightens the limits on damping
tail parameters, for example reducing the joint uncertainty on the number of
neutrino species and the primordial helium fraction by 20%.Comment: 23 pages, 25 figure
The Atacama Cosmology Telescope: Detection of mm-wave transient sources
We report on the serendipitous discovery of three transient mm-wave sources
using data from the Atacama Cosmology Telescope. The first, detected at RA =
273.8138, dec = -49.4628 at total, brightened from less than 5
mJy to at least 1100 mJy at 150 GHz with an unknown rise time shorter than
thirteen days, during which the increase from 250 mJy to 1100 mJy took only 8
minutes. Maximum flux was observed on 2019-11-8. The source's spectral index in
flux between 90 and 150 GHz was positive, . The second,
detected at RA = 105.1584, dec = -11.2434 at total, brightened
from less than 20 mJy to at least 300 mJy at 150 GHz with an unknown rise time
shorter than eight days. Maximum flux was observed on 2019-12-15. Its spectral
index was also positive, . The third, detected at RA =
301.9952, dec = 16.1652 at total, brightened from less than 8
mJy to at least 300 mJy at 150 GHz over a day or less but decayed over a few
days. Maximum flux was observed on 2018-9-11. Its spectrum was approximately
flat, with a spectral index of . None of the sources were
polarized to the limits of these measurements. The two rising-spectrum sources
are coincident in position with M and K stars, while the third is coincident
with a G star.Comment: 8 pages, 4 figures, 1 tabl
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