17 research outputs found

    Planck 2018 results. IV. Diffuse component separation

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    We present full-sky maps of the cosmic microwave background (CMB) and polarized synchrotron and thermal dust emission, derived from the third set of Planck frequency maps. These products have significantly lower contamination from instrumental systematic effects than previous versions. The methodologies used to derive these maps follow closely those described in earlier papers, adopting four methods (Commander, NILC, SEVEM, and SMICA) to extract the CMB component, as well as three methods (Commander, GNILC, and SMICA) to extract astrophysical components. Our revised CMB temperature maps agree with corresponding products in the Planck 2015 delivery, whereas the polarization maps exhibit significantly lower large-scale power, reflecting the improved data processing described in companion papers; however, the noise properties of the resulting data products are complicated, and the best available end-to-end simulations exhibit relative biases with respect to the data at the few percent level. Using these maps, we are for the first time able to fit the spectral index of thermal dust independently over 3 degree regions. We derive a conservative estimate of the mean spectral index of polarized thermal dust emission of beta_d = 1.55 +/- 0.05, where the uncertainty marginalizes both over all known systematic uncertainties and different estimation techniques. For polarized synchrotron emission, we find a mean spectral index of beta_s = -3.1 +/- 0.1, consistent with previously reported measurements. We note that the current data processing does not allow for construction of unbiased single-bolometer maps, and this limits our ability to extract CO emission and correlated components. The foreground results for intensity derived in this paper therefore do not supersede corresponding Planck 2015 products. For polarization the new results supersede the corresponding 2015 products in all respects

    Planck 2018 results. III. High Frequency Instrument data processing and frequency maps

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    This paper presents the High Frequency Instrument (HFI) data processing procedures for the Planck 2018 release. Major improvements in mapmaking have been achieved since the previous 2015 release. They enabled the first significant measurement of the reionization optical depth parameter using HFI data. This paper presents an extensive analysis of systematic effects, including the use of simulations to facilitate their removal and characterize the residuals. The polarized data, which presented a number of known problems in the 2015 Planck release, are very significantly improved. Calibration, based on the CMB dipole, is now extremely accurate and in the frequency range 100 to 353 GHz reduces intensity-to-polarization leakage caused by calibration mismatch. The Solar dipole direction has been determined in the three lowest HFI frequency channels to within one arc minute, and its amplitude has an absolute uncertainty smaller than 0.35ÎŒ0.35\muK, an accuracy of order 10−410^{-4}. This is a major legacy from the HFI for future CMB experiments. The removal of bandpass leakage has been improved by extracting the bandpass-mismatch coefficients for each detector as part of the mapmaking process; these values in turn improve the intensity maps. This is a major change in the philosophy of "frequency maps", which are now computed from single detector data, all adjusted to the same average bandpass response for the main foregrounds. Simulations reproduce very well the relative gain calibration of detectors, as well as drifts within a frequency induced by the residuals of the main systematic effect. Using these simulations, we measure and correct the small frequency calibration bias induced by this systematic effect at the 10−410^{-4} level. There is no detectable sign of a residual calibration bias between the first and second acoustic peaks in the CMB channels, at the 10−310^{-3} level

    Planck 2018 results. XII. Galactic astrophysics using polarized dust emission

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    We present 353 GHz full-sky maps of the polarization fraction p, angle \u3c8, and dispersion of angles S of Galactic dust thermal emission produced from the 2018 release of Planck data. We confirm that the mean and maximum of p decrease with increasing NH. The uncertainty on the maximum polarization fraction, pmax=22.0% at 80 arcmin resolution, is dominated by the uncertainty on the zero level in total intensity. The observed inverse behaviour between p and S is interpreted with models of the polarized sky that include effects from only the topology of the turbulent Galactic magnetic field. Thus, the statistical properties of p, \u3c8, and S mostly reflect the structure of the magnetic field. Nevertheless, we search for potential signatures of varying grain alignment and dust properties. First, we analyse the product map S 7p, looking for residual trends. While p decreases by a factor of 3--4 between NH=1020 cm 122 and NH=2 71022 cm 122, S 7p decreases by only about 25%, a systematic trend observed in both the diffuse ISM and molecular clouds. Second, we find no systematic trend of S 7p with the dust temperature, even though in the diffuse ISM lines of sight with high p and low S tend to have colder dust. We also compare Planck data with starlight polarization in the visible at high latitudes. The agreement in polarization angles is remarkable. Two polarization emission-to-extinction ratios that characterize dust optical properties depend only weakly on NH and converge towards the values previously determined for translucent lines of sight. We determine an upper limit for the polarization fraction in extinction of 13%, compatible with the pmax observed in emission. These results provide strong constraints for models of Galactic dust in diffuse gas

    Planck 2018 results. XII. Galactic astrophysics using polarized dust emission

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    We present 353 GHz full-sky maps of the polarization fraction pp, angle ψ\psi, and dispersion of angles SS of Galactic dust thermal emission produced from the 2018 release of Planck data. We confirm that the mean and maximum of pp decrease with increasing NHN_H. The uncertainty on the maximum polarization fraction, pmax=22.0p_\mathrm{max}=22.0% at 80 arcmin resolution, is dominated by the uncertainty on the zero level in total intensity. The observed inverse behaviour between pp and SS is interpreted with models of the polarized sky that include effects from only the topology of the turbulent Galactic magnetic field. Thus, the statistical properties of pp, ψ\psi, and SS mostly reflect the structure of the magnetic field. Nevertheless, we search for potential signatures of varying grain alignment and dust properties. First, we analyse the product map S×pS \times p, looking for residual trends. While pp decreases by a factor of 3--4 between NH=1020N_H=10^{20} cm−2^{-2} and NH=2×1022N_H=2\times 10^{22} cm−2^{-2}, S×pS \times p decreases by only about 25%, a systematic trend observed in both the diffuse ISM and molecular clouds. Second, we find no systematic trend of S×pS \times p with the dust temperature, even though in the diffuse ISM lines of sight with high pp and low SS tend to have colder dust. We also compare Planck data with starlight polarization in the visible at high latitudes. The agreement in polarization angles is remarkable. Two polarization emission-to-extinction ratios that characterize dust optical properties depend only weakly on NHN_H and converge towards the values previously determined for translucent lines of sight. We determine an upper limit for the polarization fraction in extinction of 13%, compatible with the pmaxp_\mathrm{max} observed in emission. These results provide strong constraints for models of Galactic dust in diffuse gas

    A new chromosome aberration in a case of acute myeloid leukemia

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    A new dic(7;12)(p12.21;p12.2) chromosome aberration was identified in an acute myeloid leukemia with FAB-M1 morphology and was cloned. Fluorescence in situ hybridization and genomic quantitative polymerase chain reaction mapping experiments revealed the precise localization of the breakpoints, at 7p12, just 5\u2032 to the GRB10 gene, and 12p11, within a genomic region containing no known genes. As a result, a new dicentric chromosome is created, dic(7;12), with the consequent deletion of 50 Mb at 7p, from the telomere to the GRB10 region, and of 30 Mb at 12p, from the telomere to p11. Several genes are included in the affected areas

    Il progetto ALPS-GPSQuakenet

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    In the higher part of many Italian alpine regions the population is rapidly decreasing. This fact directly influences landscape and forest management criteria. In particular, large pastures and agricultured areas are being covered by trees or bushes, which change the landscape. This is a well known trend but it is very difficult to evaluate the extension and the evolution of these phenomena. A new approach to this problem has been developed at the Laboratorio Ambiente e Territorio, which makes possible to determine changes of the forested areas over time. Series of aerial photographs taken in different years (1954, 1980, 1994) have been compared using automatic algorithms which exploit the GRASS GIS (Grass GIS is a public domain Geographic Information System) image analysis capability. This method has proved to be effective for the automatic determination of the widening of the forested areas. A precise knowledge of the forest coverage evolution is very precious to enhance forest and landscape management criteria. It can also be combined with demographic information to better explain landscape change. Further investigations have been carried out to provide a photgrammetric tecnique for the determination of the growing stock. Such tecnique has already been set up in the \u201950 and in the \u201960 using ad hoc photogrammetric surveys with mean scale of 1:10.000 and 1:20.000 for flat areas and plantations. In this work an effort has been made to apply these technique to sparse forests of spruce and larch in mountain areas using panchromatic images with mean scale 1:40.000. Measurements on the images of the single trees have been checked against the data from forest management plans for the Trentino region
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