3,123 research outputs found
All sky CMB map from cosmic strings integrated Sachs-Wolfe effect
By actively distorting the Cosmic Microwave Background (CMB) over our past
light cone, cosmic strings are unavoidable sources of non-Gaussianity.
Developing optimal estimators able to disambiguate a string signal from the
primordial type of non-Gaussianity requires calibration over synthetic full sky
CMB maps, which till now had been numerically unachievable at the resolution of
modern experiments. In this paper, we provide the first high resolution full
sky CMB map of the temperature anisotropies induced by a network of cosmic
strings since the recombination. The map has about 200 million sub-arcminute
pixels in the healpix format which is the standard in use for CMB analyses
(Nside=4096). This premiere required about 800,000 cpu hours; it has been
generated by using a massively parallel ray tracing method piercing through a
thousands of state of art Nambu-Goto cosmic string numerical simulations which
pave the comoving volume between the observer and the last scattering surface.
We explicitly show how this map corrects previous results derived in the flat
sky approximation, while remaining completely compatible at the smallest
scales.Comment: 8 pages, 4 figures, uses RevTeX. References added, matches published
versio
Evidence for Gravitational Lensing of the Cosmic Microwave Background Polarization from Cross-Correlation with the Cosmic Infrared Background
We reconstruct the gravitational lensing convergence signal from cosmic microwave background (CMB) polarization data taken by the Polarbear experiment and cross-correlate it with cosmic infrared background maps from the Herschel satellite. From the cross spectra, we obtain evidence for gravitational lensing of the CMB polarization at a statistical significance of 4.0Ï and indication of the presence of a lensing B-mode signal at a significance of 2.3Ï. We demonstrate that our results are not biased by instrumental and astrophysical systematic errors by performing null tests, checks with simulated and real data, and analytical calculations. This measurement of polarization lensing, made via the robust cross-correlation channel, not only reinforces POLARBEAR auto-correlation measurements, but also represents one of the early steps towards establishing CMB polarization lensing as a powerful new probe of cosmology and astrophysics
The effect of a scanning flat fold mirror on a CMB B-mode experiment
We investigate the possibility of using a flat-fold beam steering mirror for
a CMB B-mode experiment. An aluminium flat-fold mirror is found to add
0.075% polarization, which varies in a scan synchronous way. Time-domain
simulations of a realistic scanning pattern are performed, and the effect on
the power-spectrum illustrated and a possible method of correction applied.Comment: 8 pages, 5 figures. Accepted for publication in Rev Sci Ins
The Influence of Physical Parameters and Microbiology Leachet to the Health of Environment at TPA Muara Fajar Rumbai Pekanbaru
The general condition of âCity trashâ shows typical characteristics. The The city waste largest had a composition of the organic worth rata-rata 79,164 %, the inorganic waste was only 20,836 %. Type of research was a survey method. Location sampling was in Muara Fajar landfill Pekanbaru. Samples were taken and analyzed the level of physics and biology leachet in the laboratory, data obtain were then analyzed using descriptive, in accordance with SNI 06-2412-1991. The data research the interview, observation and laboratory. Two code samples to water lindi obtained analysis on codes sample that I and II or temperature is 250C. TSS on codes I got the sample of 70 mg/l and sample code II 190 mg/l. ph on codes samples I and II obtained a result of 8, as for the sample e.coli on codes I and II obtained the infinite
Stability of the Submillimeter Brightness of the Atmosphere Above Mauna Kea, Chajnantor and the South Pole
The summit of Mauna Kea in Hawaii, the area near Cerro Chajnantor in Chile,
and the South Pole are sites of large millimeter or submillimeter wavelength
telescopes. We have placed 860 GHz sky brightness monitors at all three sites
and present a comparative study of the measured submillimeter brightness due to
atmospheric thermal emission. We report the stability of that quantity at each
site.Comment: 6 figure
Temperature effects on the 15-85-micron spectra of olivines and pyroxenes
Far-infrared spectra of laboratory silicates are normally obtained at room
temperature even though the grains responsible for astronomical silicate
emission bands seen at wavelengths >20 micron are likely to be at temperatures
below ~150 K. In order to investigate the effect of temperature on silicate
spectra, we have obtained absorption spectra of powdered forsterite and
olivine, along with two orthoenstatites and diopside clinopyroxene, at 3.5+-0.5
K and at room temperature (295+-2K). To determine the changes in the spectra
the resolution must be increased from 1 to 0.25 cm^-1 at both temperatures
since a reduction in temperature reduces the phonon density, thereby reducing
the width of the infrared peaks. Several bands observed at 295 K split at 3.5
K. At 3.5 K the widths of isolated single bands in olivine, enstatites and
diopside are ~ 90% of their 295 K-widths. However, in forsterite the
3.5-K-widths of the 31-, 49- and 69-micron bands are, respectively, 90%, 45%
and 31% of their 295 K widths. Due to an increase in phonon energy as the
lattice contracts, 3.5-K-singlet peaks occur at shorter wavelengths than do the
corresponding 295-K peaks; the magnitude of the wavelength shift increases from
\~ 0-0.2 micron at 25 micron to ~0.9 micron at 80 micron. Changes in the
relative absorbances of spectral peaks are also observed. The temperature
dependence of lambda_pk and bandwidth shows promise as a means to deduce
characteristic temperatures of mineralogically distinct grain populations. In
addition, the observed changes in band strength with temperature will affect
estimates of grain masses and relative mineral abundances inferred using
room-temperature laboratory data.Comment: 11 pages, 7 figures including figures 3a and 3b. includes latex and
eps files. Accepted by MNRAS on 15th March 200
Planck 2015 results XXIV. Cosmology from Sunyaev-Zeldovich cluster counts
Acknowledgements. The Planck Collaboration acknowledges the support of:
ESA; CNES, and CNRS/INSU-IN2P3-INP (France); ASI, CNR, and INAF
(Italy); NASA and DoE (USA); STFC and UKSA (UK); CSIC, MINECO, JA
and RES (Spain); Tekes, AoF, and CSC (Finland); DLR and MPG (Germany);
CSA (Canada); DTU Space (Denmark); SER/SSO (Switzerland); RCN (Norway); SFI (Ireland); FCT/MCTES (Portugal); ERC and PRACE (EU). A description of the Planck Collaboration and a list of its members, indicating which
technical or scientific activities they have been involved in, can be found at
http://www.cosmos.esa.int/web/planck/planck-collaboration.We present cluster counts and corresponding cosmological constraints from the Planck full mission data set. Our catalogue consists of 439 clusters detected via their Sunyaev-Zeldovich (SZ) signal down to a signal-to-noise ratio of 6, and is more than a factor of 2 larger than the 2013 Planck cluster cosmology sample. The counts are consistent with those from 2013 and yield compatible constraints under the same modelling assumptions. Taking advantage of the larger catalogue, we extend our analysis to the two-dimensional distribution in redshift and signal-to-noise. We use mass estimates from two recent studies of gravitational lensing of background galaxies by Planck clusters to provide priors on the hydrostatic bias parameter, (1âb). In addition, we use lensing of cosmic microwave background (CMB) temperature fluctuations by Planck clusters as an independent constraint on this parameter. These various calibrations imply constraints on the present-day amplitude of matter fluctuations in varying degrees of tension with those from the Planck analysis of primary fluctuations in the CMB; for the lowest estimated values of (1âb) the tension is mild, only a little over one standard deviation, while it remains substantial (3.7Ï) for the largest estimated value. We also examine constraints on extensions to the base flat ÎCDM model by combining the cluster and CMB constraints. The combination appears to favour non-minimal neutrino masses, but this possibility does little to relieve the overall tension because it simultaneously lowers the implied value of the Hubble parameter, thereby exacerbating the discrepancy with most current astrophysical estimates. Improving the precision of cluster mass calibrations from the current 10%-level to 1% would significantly strengthen these combined analyses and provide a stringent test of the base ÎCDM model.European Space AgencyCentre National D'etudes SpatialesCNRS/INSU-IN2P3-INP (France)Italian Space Agency (ASI)Italian National Research CouncilIstituto Nazionale Astrofisica (INAF)National Aeronautics & Space Administration (NASA)United States Department of Energy (DOE)UKSA (UK)Consejo Superior de Investigaciones Cientificas (CSIC)MINECO (Spain)JA (Spain)RES (Spain)Finnish Funding Agency for Technology & Innovation (TEKES)AoF (Finland)CSC (Finland)Helmholtz AssociationGerman Aerospace Centre (DLR)Max Planck SocietyCSA (Canada)DTU Space (Denmark)SER/SSO (Switzerland)RCN (Norway)Science Foundation IrelandPortuguese Foundation for Science and TechnologyERC (EU)European Union (EU)Science & Technology Facilities Council (STFC)
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The High Frequency Instrument of Planck: Requirements and Design
The Planck satellite is a project of the European Space Agency based on a wide international collaboration, including United States and Canadian laboratories. It is dedicated to the measurement of the anisotropy of the Cosmic Microwave Background (CMB) with unprecedented sensitivity and angular resolution. The detectors of its High frequency Instrument (HFI) are bolometers cooled down to 100 mK. Their sensitivity will be limited by the photon noise of the CMB itself at low frequencies, and of the instrument background at high frequencies. The requirements on the measurement chain are directly related to the strategy of observation used for the satellite. Due to the scanning on the sky, time features of the measurement chain are directly transformed into angular features in the sky maps. This impacts the bolometer design as well as other elements: For example, the cooling system must present outstanding temperature stability, and the amplification chain must show, down to very low frequencies, a flat noise spectrum
Planck 2013 results. XX. Cosmology from SunyaevâZeldovich cluster counts
We present constraints on cosmological parameters using number counts as a function of redshift for a sub-sample of 189 galaxy clusters from the Planck SZ (PSZ) catalogue. The PSZ is selected through the signature of the Sunyaev-Zeldovich (SZ) effect, and the sub-sample used here has a signal-to-noise threshold of seven, with each object confirmed as a cluster and all but one with a redshift estimate. We discuss the completeness of the sample and our construction of a likelihood analysis. Using a relation between mass M and SZ signal Y calibrated to X-ray measurements, we derive constraints on the power spectrum amplitude Ï8 and matter density parameter Ωm in a flat ÎCDM model. We test the robustness of our estimates and find that possible biases in the YâM relation and the halo mass function are larger than the statistical uncertainties from the cluster sample. Assuming the X-ray determined mass to be biased low relative to the true mass by between zero and 30%, motivated by comparison of the observed mass scaling relations to those from a set of numerical simulations, we find that Ï8 = 0.75 ± 0.03, Ωm = 0.29 ± 0.02, and Ï8(Ωm/ 0.27)0.3 = 0.764 ± 0.025. The value of Ï8 is degenerate with the mass bias; if the latter is fixed to a value of 20% (the central value from numerical simulations) we find Ï8(Ωm/0.27)0.3 = 0.78 ± 0.01 and a tighter one-dimensional range Ï8 = 0.77 ± 0.02. We find that the larger values of Ï8 and Ωm preferred by Planckâs measurements of the primary CMB anisotropies can be accommodated by a mass bias of about 40%. Alternatively, consistency with the primary CMB constraints can be achieved by inclusion of processes that suppress power on small scales relative to the ÎCDM model, such as a component of massive neutrinos. We place our results in the context of other determinations of cosmologicalparameters, and discuss issues that need to be resolved in order to make further progress in this field.Science & Technology Facilities Council (STFC)
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Planck 2013 results. XXII. Constraints on inflation
We analyse the implications of the Planck data for cosmic inflation. The Planck nominal mission temperature anisotropy measurements, combined with the WMAP large-angle polarization, constrain the scalar spectral index to be ns = 0.9603 ± 0.0073, ruling out exact scale invariance at over 5Ï.Planck establishes an upper bound on the tensor-to-scalar ratio of r< 0.11 (95% CL). The Planck data thus shrink the space of allowed standard inflationary models, preferring potentials with VâČâČ< 0. Exponential potential models, the simplest hybrid inflationary models, and monomial potential models of degree n â„ 2 do not provide a good fit to the data. Planck does not find statistically significant running of the scalar spectral index, obtaining dns/ dlnk = â 0.0134 ± 0.0090. We verify these conclusions through a numerical analysis, which makes no slow-roll approximation, and carry out a Bayesian parameter estimation and model-selection analysis for a number of inflationary models including monomial, natural, and hilltop potentials. For each model, we present the Planck constraints on the parameters of the potential and explore several possibilities for the post-inflationary entropy generation epoch, thus obtaining nontrivial data-driven constraints. We also present a direct reconstruction of the observable range of the inflaton potential. Unless a quartic term is allowed in the potential, we find results consistent with second-order slow-roll predictions. We also investigate whether the primordial power spectrum contains any features. We find that models with a parameterized oscillatory feature improve the fit by ÎÏ2eff â 10; however, Bayesian evidence does not prefer these models. We constrain several single-field inflation models with generalized Lagrangians by combining power spectrum data with Planck bounds on fNL. Planck constrains with unprecedented accuracy the amplitude and possible correlation (with the adiabatic mode) of non-decaying isocurvature fluctuations. The fractional primordial contributions of cold dark matter (CDM) isocurvature modes of the types expected in the curvaton and axion scenarios have upper bounds of 0.25% and 3.9% (95% CL), respectively. In models with arbitrarily correlated CDM or neutrino isocurvature modes, an anticorrelated isocurvature component can improve the Ï2eff by approximately 4 as a result of slightly lowering the theoretical prediction for the â âČ 40 multipoles relative to the higher multipoles. Nonetheless, the data are consistent with adiabatic initial conditions.European Space AgencyCentre National D'etudes SpatialesCNRS/INSU-IN2P3-INP (France)Italian Space Agency (ASI)Italian National Research CouncilIstituto Nazionale Astrofisica (INAF)National Aeronautics & Space Administration (NASA)United States Department of Energy (DOE)Science & Technology Facilities Council (STFC)UKSA (UK)Consejo Superior de Investigaciones Cientificas (CSIC)Spanish GovernmentJARES (Spain)Finnish Funding Agency for Technology & Innovation (TEKES)AoFCSC (Finland)Helmholtz AssociationGerman Aerospace Centre (DLR)Max Planck SocietyCSA (Canada)DTU Space (Denmark)SER/SSO (Switzerland)RCN (Norway)Science Foundation IrelandPortuguese Foundation for Science and TechnologyEuropean Union (EU)Science & Technology Facilities Council (STFC)
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