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Publications (3 of 3) Show all publications
Akrami, Y., Ashdown, M., Aumont, J., Baccigalupi, C., Ballardini, M., Banday, A. J., . . . Zonca, A. (2020). Planck intermediate results LV. Reliability and thermal properties of high-frequency sources in the Second Planck Catalogue of Compact Sources. Astronomy and Astrophysics, 644, Article ID A99.
Open this publication in new window or tab >>Planck intermediate results LV. Reliability and thermal properties of high-frequency sources in the Second Planck Catalogue of Compact Sources
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2020 (English)In: Astronomy and Astrophysics, ISSN 0004-6361, E-ISSN 1432-0746, Vol. 644, article id A99Article in journal (Refereed) Published
Abstract [en]

We describe an extension of the most recent version of the Planck Catalogue of Compact Sources (PCCS2), produced using a new multi-band Bayesian Extraction and Estimation Package (BeeP). BeeP assumes that the compact sources present in PCCS2 at 857 GHz have a dust-like spectral energy distribution (SED), which leads to emission at both lower and higher frequencies, and adjusts the parameters of the source and its SED to fit the emission observed in Planck's three highest frequency channels at 353, 545, and 857 GHz, as well as the IRIS map at 3000 GHz. In order to reduce confusion regarding diffuse cirrus emission, BeeP's data model includes a description of the background emission surrounding each source, and it adjusts the confidence in the source parameter extraction based on the statistical properties of the spatial distribution of the background emission. BeeP produces the following three new sets of parameters for each source: (a) fits to a modified blackbody (MBB) thermal emission model of the source; (b) SED-independent source flux densities at each frequency considered; and (c) fits to an MBB model of the background in which the source is embedded. BeeP also calculates, for each source, a reliability parameter, which takes into account confusion due to the surrounding cirrus. This parameter can be used to extract sub-samples of high-frequency sources with statistically well-understood properties. We define a high-reliability subset (BeeP/base), containing 26 083 sources (54.1% of the total PCCS2 catalogue), the majority of which have no information on reliability in the PCCS2. We describe the characteristics of this specific high-quality subset of PCCS2 and its validation against other data sets, specifically for: the sub-sample of PCCS2 located in low-cirrus areas; the Planck Catalogue of Galactic Cold Clumps; the Herschel GAMA15-field catalogue; and the temperature- and spectral-index-reconstructed dust maps obtained with Planck's Generalized Needlet Internal Linear Combination method. The results of the BeeP extension of PCCS2, which are made publicly available via the Planck Legacy Archive, will enable the study of the thermal properties of well-defined samples of compact Galactic and extragalactic dusty sources.

Keywords
catalogs, cosmology: observations, submillimeter: general
National Category
Physical Sciences
Identifiers
urn:nbn:se:su:diva-189926 (URN)10.1051/0004-6361/201936794 (DOI)000599932200001 ()
Available from: 2021-02-06 Created: 2021-02-06 Last updated: 2022-03-07Bibliographically approved
Akrami, Y., Ashdown, M., Aumont, J., Baccigalupi, C., Ballardini, M., Banday, A. J., . . . Zonca, A. (2020). Planck intermediate results LVI. Detection of the CMB dipole through modulation of the thermal Sunyaev-Zeldovich effect: Eppur si muove II. Astronomy and Astrophysics, 644, Article ID A100.
Open this publication in new window or tab >>Planck intermediate results LVI. Detection of the CMB dipole through modulation of the thermal Sunyaev-Zeldovich effect: Eppur si muove II
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2020 (English)In: Astronomy and Astrophysics, ISSN 0004-6361, E-ISSN 1432-0746, Vol. 644, article id A100Article in journal (Refereed) Published
Abstract [en]

The largest temperature anisotropy in the cosmic microwave background (CMB) is the dipole, which has been measured with increasing accuracy for more than three decades, particularly with the Planck satellite. The simplest interpretation of the dipole is that it is due to our motion with respect to the rest frame of the CMB. Since current CMB experiments infer temperature anisotropies from angular intensity variations, the dipole modulates the temperature anisotropies with the same frequency dependence as the thermal Sunyaev-Zeldovich (tSZ) effect. We present the first, and significant, detection of this signal in the tSZ maps and find that it is consistent with direct measurements of the CMB dipole, as expected. The signal contributes power in the tSZ maps, which is modulated in a quadrupolar pattern, and we estimate its contribution to the tSZ bispectrum, noting that it contributes negligible noise to the bispectrum at relevant scales.

Keywords
cosmic background radiation, cosmology: observations, relativistic processes, reference systems
National Category
Physical Sciences
Identifiers
urn:nbn:se:su:diva-190663 (URN)10.1051/0004-6361/202038053 (DOI)000599932200002 ()2-s2.0-85097877481 (Scopus ID)
Available from: 2021-03-03 Created: 2021-03-03 Last updated: 2022-11-08Bibliographically approved
Akrami, Y., Andersen, K. J., Ashdown, M., Baccigalupi, C., Ballardini, M., Banday, A. J., . . . Zonca, A. (2020). Planck intermediate results: LVII. Joint Planck LFI and HFI data processing. Astronomy and Astrophysics, 643, Article ID A42.
Open this publication in new window or tab >>Planck intermediate results: LVII. Joint Planck LFI and HFI data processing
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2020 (English)In: Astronomy and Astrophysics, ISSN 0004-6361, E-ISSN 1432-0746, Vol. 643, article id A42Article in journal (Refereed) Published
Abstract [en]

We present the NPIPE processing pipeline, which produces calibrated frequency maps in temperature and polarization from data from the Planck Low Frequency Instrument (LFI) and High Frequency Instrument (HFI) using high-performance computers. NPIPE represents a natural evolution of previous Planck analysis efforts, and combines some of the most powerful features of the separate LFI and HFI analysis pipelines. For example, following the LFI 2018 processing procedure, NPIPE uses foreground polarization priors during the calibration stage in order to break scanning-induced degeneracies. Similarly, NPIPE employs the HFI 2018 time-domain processing methodology to correct for bandpass mismatch at all frequencies. In addition, NPIPE introduces several improvements, including, but not limited to: inclusion of the 8% of data collected during repointing manoeuvres; smoothing of the LFI reference load data streams; in-flight estimation of detector polarization parameters; and construction of maximally independent detector-set split maps. For component-separation purposes, important improvements include: maps that retain the CMB Solar dipole, allowing for high-precision relative calibration in higher-level analyses; well-defined single-detector maps, allowing for robust CO extraction; and HFI temperature maps between 217 and 857 GHz that are binned into 0′.9 pixels (Nside = 4096), ensuring that the full angular information in the data is represented in the maps even at the highest Planck resolutions. The net effect of these improvements is lower levels of noise and systematics in both frequency and component maps at essentially all angular scales, as well as notably improved internal consistency between the various frequency channels. Based on the NPIPE maps, we present the first estimate of the Solar dipole determined through component separation across all nine Planck frequencies. The amplitude is (3366.6 ± 2.7) μK, consistent with, albeit slightly higher than, earlier estimates. From the large-scale polarization data, we derive an updated estimate of the optical depth of reionization of τ = 0.051 ± 0.006, which appears robust with respect to data and sky cuts. There are 600 complete signal, noise and systematics simulations of the full-frequency and detector-set maps. As a Planck first, these simulations include full time-domain processing of the beam-convolved CMB anisotropies. The release of NPIPE maps and simulations is accompanied with a complete suite of raw and processed time-ordered data and the software, scripts, auxiliary data, and parameter files needed to improve further on the analysis and to run matching simulations.

Keywords
cosmic background radiation, cosmology: observations, cosmological parameters, Galaxy: general, methods: data analysis
National Category
Physical Sciences
Identifiers
urn:nbn:se:su:diva-188740 (URN)10.1051/0004-6361/202038073 (DOI)000593930000001 ()2-s2.0-85096100312 (Scopus ID)
Available from: 2021-01-18 Created: 2021-01-18 Last updated: 2022-11-08Bibliographically approved
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-5444-9327

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