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Planck 2018 results: IV. Diffuse component separation

Y. Akrami 1 M. Ashdown J. Aumont C. Baccigalupi M. Ballardini A. J. Banday 2 R. B. Barreiro N. Bartolo S. Basak K. Benabed 3 M. Bersanelli 4 P. Bielewicz J. R. Bond 5 J. Borrill 6 F. R. Bouchet 7 F. Boulanger 8, 9 M. Bucher 10 C. Burigana E. Calabrese J.-F. Cardoso 11 J. Carron 12 B. Casaponsa A. Challinor L. P. L. Colombo C. Combet 13 B. P. Crill F. Cuttaia P. de Bernardis 14 A. de Rosa G. de Zotti J. Delabrouille 10 J.-M. Delouis 3 E. Di Valentino C. Dickinson J. M. Diego S. Donzelli O. Doré 15 A. Ducout X. Dupac G. Efstathiou F. Elsner 3 T. A. Enßlin H. K. Eriksen * E. Falgarone 16, 1 R. Fernandez-Cobos F. Finelli F. Forastieri M. Frailis A. A. Fraisse E. Franceschi A. Frolov 17 S. Galeotta S. Galli K. Ganga 10 R. T. Génova-Santos M. Gerbino T. Ghosh 18 J. González-Nuevo K. M. Górski 15 Serge Gratton 19 A. Gruppuso J. E. Gudmundsson W. Handley F. K. Hansen G. Helou D. Herranz S. R. Hildebrandt Z. Huang 20 A. H. Jaffe A. Karakci E. Keihänen R. Keskitalo K. Kiiveri J. Kim T. S. Kisner 6 N. Krachmalnicoff M. Kunz H. Kurki-Suonio G. Lagache 18 J.-M. Lamarre 16 A. Lasenby M. Lattanzi 21 C. R. Lawrence M. Le Jeune 10 F. Levrier 16 M. Liguori P. B. Lilje V. Lindholm M. López-Caniego P. M. Lubin Y.-Z. Ma J. F. Macías-Pérez 13 G. Maggio D. Maino N. Mandolesi A. Mangilli 2 A. Marcos-Caballero M. Maris P. G. Martin E. Martínez-González S. Matarrese 22 N. Mauri J. D. Mcewen P. R. Meinhold A. Melchiorri 23 A. Mennella M. Migliaccio M.-A. Miville-Deschênes 24, 25 D. Molinari A. Moneti 3 L. Montier 2 G. Morgante P. Natoli F. Oppizzi L. Pagano 18 D. Paoletti B. Partridge M. Peel V. Pettorino 25 F. Piacentini G. Polenta J.-L. Puget 18 J. P. Rachen M. Reinecke M. Remazeilles 26 A. Renzi G. Rocha 15 G. Roudier 16, 10 J. A. Rubiño-Martín B. Ruiz-Granados L. Salvati 18 M. Sandri 27 M. Savelainen D. Scott 28 D. S. Seljebotn C. Sirignano L. D. Spencer A.-S. Suur-Uski J. A. Tauber D. Tavagnacco M. Tenti H. Thommesen L. Toffolatti M. Tomasi 29 T. Trombetti J. Valiviita B. van Tent 30 P. Vielva F. Villa N. Vittorio B. D. Wandelt 3 I. K. Wehus A. Zacchei A. Zonca
* Corresponding author
1 Astrophysique
LPENS (UMR_8023) - Laboratoire de physique de l'ENS - ENS Paris
Abstract : 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° 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.
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Y. Akrami, M. Ashdown, J. Aumont, C. Baccigalupi, M. Ballardini, et al.. Planck 2018 results: IV. Diffuse component separation. Astronomy and Astrophysics - A&A, EDP Sciences, 2020, 641, pp.A4. ⟨10.1051/0004-6361/201833881⟩. ⟨cea-02936942⟩



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