Planck intermediate results. XIX. An overview of the polarized thermal emission from Galactic dust

Planck Collaboration; P A R Ade; N Aghanim; D Alina; M I R Alves; C Armitage-Caplan; M Arnaud; D Arzoumanian; M Ashdown; F Atrio-Barandela; J Aumont; C Baccigalupi; A J Banday; R B Barreiro; E Battaner; K Benabed; A Benoit-L√©vy; J-P Bernard; M Bersanelli; P Bielewicz; J J Bock; J R Bond; J Borrill; F R Bouchet; F Boulanger; A Bracco; C Burigana; R C Butler; J-F Cardoso; A Catalano; A Chamballu; R-R Chary; H C Chiang; P R Christensen; S Colombi; L P L Colombo; C Combet; F Couchot; A Coulais; B P Crill; A Curto; F Cuttaia; L Danese; R D Davies; R J Davis; P de Bernardis; E M de Gouveia Dal Pino; A de Rosa; G de Zotti; J Delabrouille; F-X D√©sert; C Dickinson; J M Diego; S Donzelli; O Dor√©; M Douspis; J Dunkley; X Dupac; G Efstathiou; T A En√ülin; H K Eriksen; E Falgarone; K Ferri√®re; F Finelli; O Forni; M Frailis; A A Fraisse; E Franceschi; S Galeotta; K Ganga; T Ghosh; M Giard; Y Giraud-H√©raud; J Gonz√°lez-Nuevo; K M G√≥rski; A Gregorio; A Gruppuso; V Guillet; F K Hansen; D L Harrison; G Helou; C Hern√°ndez-Monteagudo; S R Hildebrandt; E Hivon; M Hobson; W A Holmes; A Hornstrup; K M Huffenberger; A H Jaffe; T R Jaffe; W C Jones; M Juvela; E Keih√§nen; R Keskitalo; T S Kisner; R Kneissl; J Knoche; M Kunz; H Kurki-Suonio; G Lagache; A L√§hteenm√§ki; J-M Lamarre; A Lasenby; C R Lawrence; J P Leahy; R Leonardi; F Levrier; M Liguori; P B Lilje; M Linden-V√∏rnle; M L√≥pez-Caniego; P M Lubin; J F Mac√≠as-P√©rez; B Maffei; A M Magalh√£es; D Maino; N Mandolesi; M Maris; D J Marshall; P G Martin; E Mart√≠nez-Gonz√°lez; S Masi; S Matarrese; P Mazzotta; A Melchiorri; L Mendes; A Mennella; M Migliaccio; M-A Miville-Desch√™nes; A Moneti; L Montier; G Morgante; D Mortlock; D Munshi; J A Murphy; P Naselsky; F Nati; P Natoli; C B Netterfield; F Noviello; D Novikov; I Novikov; C A Oxborrow; L Pagano; F Pajot; R Paladini; D Paoletti; F Pasian; T J Pearson; O Perdereau; L Perotto; F Perrotta; F Piacentini; M Piat; D Pietrobon; S Plaszczynski; F Poidevin; E Pointecouteau; G Polenta; L Popa; G W Pratt; S Prunet; J-L Puget; J P Rachen; W T Reach; R Rebolo; M Reinecke; M Remazeilles; C Renault; S Ricciardi; T Riller; I Ristorcelli; G Rocha; C Rosset; G Roudier; J A Rubi√±o-Mart√≠n; B Rusholme; M Sandri; G Savini; D Scott; L D Spencer; V Stolyarov; R Stompor; R Sudiwala; D Sutton; A-S Suur-Uski; J-F Sygnet; J A Tauber; L Terenzi; L Toffolatti; M Tomasi; M Tristram; M Tucci; G Umana; L Valenziano; J Valiviita; B Van Tent; P Vielva; F Villa; L A Wade; B D Wandelt; A Zacchei; A Zonca

doi:10.1051/0004-6361/201424082

Planck intermediate results. XIX. An overview of the polarized thermal emission from Galactic dust

Planck Collaboration, P A R Ade, N Aghanim, D Alina, M I R Alves, C Armitage-Caplan, M Arnaud, D Arzoumanian, M Ashdown, F Atrio-Barandela, J Aumont, C Baccigalupi, A J Banday, R B Barreiro, E Battaner, K Benabed, A Benoit-L√©vy, J-P Bernard, M Bersanelli, P BielewiczJ J Bock, J R Bond, J Borrill, F R Bouchet, F Boulanger, A Bracco, C Burigana, R C Butler, J-F Cardoso, A Catalano, A Chamballu, R-R Chary, H C Chiang, P R Christensen, S Colombi, L P L Colombo, C Combet, F Couchot, A Coulais, B P Crill, A Curto, F Cuttaia, L Danese, R D Davies, R J Davis, P de Bernardis, E M de Gouveia Dal Pino, A de Rosa, G de Zotti, J Delabrouille, F-X D√©sert, C Dickinson, J M Diego, S Donzelli, O Dor√©, M Douspis, J Dunkley, X Dupac, G Efstathiou, T A En√ülin, H K Eriksen, E Falgarone, K Ferri√®re, F Finelli, O Forni, M Frailis, A A Fraisse, E Franceschi, S Galeotta, K Ganga, T Ghosh, M Giard, Y Giraud-H√©raud, J Gonz√°lez-Nuevo, K M G√≥rski, A Gregorio, A Gruppuso, V Guillet, F K Hansen, D L Harrison, G Helou, C Hern√°ndez-Monteagudo, S R Hildebrandt, E Hivon, M Hobson, W A Holmes, A Hornstrup, K M Huffenberger, A H Jaffe, T R Jaffe, W C Jones, M Juvela, E Keih√§nen, R Keskitalo, T S Kisner, R Kneissl, J Knoche, M Kunz, H Kurki-Suonio, G Lagache, A L√§hteenm√§ki, J-M Lamarre, A Lasenby, C R Lawrence, J P Leahy, R Leonardi, F Levrier, M Liguori, P B Lilje, M Linden-V√∏rnle, M L√≥pez-Caniego, P M Lubin, J F Mac√≠as-P√©rez, B Maffei, A M Magalh√£es, D Maino, N Mandolesi, M Maris, D J Marshall, P G Martin, E Mart√≠nez-Gonz√°lez, S Masi, S Matarrese, P Mazzotta, A Melchiorri, L Mendes, A Mennella, M Migliaccio, M-A Miville-Desch√™nes, A Moneti, L Montier, G Morgante, D Mortlock, D Munshi, J A Murphy, P Naselsky, F Nati, P Natoli, C B Netterfield, F Noviello, D Novikov, I Novikov, C A Oxborrow, L Pagano, F Pajot, R Paladini, D Paoletti, F Pasian, T J Pearson, O Perdereau, L Perotto, F Perrotta, F Piacentini, M Piat, D Pietrobon, S Plaszczynski, F Poidevin, E Pointecouteau, G Polenta, L Popa, G W Pratt, S Prunet, J-L Puget, J P Rachen, W T Reach, R Rebolo, M Reinecke, M Remazeilles, C Renault, S Ricciardi, T Riller, I Ristorcelli, G Rocha, C Rosset, G Roudier, J A Rubi√±o-Mart√≠n, B Rusholme, M Sandri, G Savini, D Scott, L D Spencer, V Stolyarov, R Stompor, R Sudiwala, D Sutton, A-S Suur-Uski, J-F Sygnet, J A Tauber, L Terenzi, L Toffolatti, M Tomasi, M Tristram, M Tucci, G Umana, L Valenziano, J Valiviita, B Van Tent, P Vielva, F Villa, L A Wade, B D Wandelt, A Zacchei, A Zonca

Research output: Contribution to journal › Article › peer-review

Abstract

This paper presents an overview of the polarized sky as seen by Planck HFI at 353 GHz, which is the most sensitive Planck channel for dust polarization. We construct and analyse maps of dust polarization fraction and polarization angle at 1¬∞ resolution, taking into account noise bias and possible systematic effects. The sensitivity of the Planck HFI polarization measurements allows for the first time a mapping of Galactic dust polarized emission on large scales, including low column density regions. We find that the maximum observed dust polarization fraction is high (p_max = 19.8%), in particular in some regions of moderate hydrogen column density (N_H <2 √ó 10²¹ cm^-2). The polarization fraction displays a large scatter at N_H below a few 10²¹ cm^-2. There is a general decrease in the dust polarization fraction with increasing column density above N_H ‚âÉ 1 √ó 10²¹ cm^-2 and in particular a sharp drop above N_H ‚âÉ 1.5 √ó 10²² cm^-2. We characterize the spatial structure of the polarization angle using the angle dispersion function. We find that the polarization angle is ordered over extended areas of several square degrees, separated by filamentary structures of high angle dispersion function. These appear as interfaces where the sky projection of the magnetic field changes abruptly without variations in the column density. The polarization fraction is found to be anti-correlated with the dispersion of polarization angles. These results suggest that, at the resolution of 1¬∞, depolarization is due mainly to fluctuations in the magnetic field orientation along the line of sight, rather than to the loss of grain alignment in shielded regions. We also compare the polarization of thermal dust emission with that of synchrotron measured with Planck, low-frequency radio data, and Faraday rotation measurements toward extragalactic sources. These components bear resemblance along the Galactic plane and in some regions such as the Fan and North Polar Spur regions. The poor match observed in other regions shows, however, that dust, cosmic-ray electrons, and thermal electrons generally sample different parts of the line of sight. Appendices are available in electronic form at http://www.aanda.org

Original language	English
Journal	Astronomy and Astrophysics
Volume	576
DOIs	https://doi.org/10.1051/0004-6361/201424082
Publication status	Published - Apr 2015

Keywords

ISM: general
dust
extinction
ISM: magnetic fields
ISM:
clouds
submillimeter: ISM

Access to Document

10.1051/0004-6361/201424082

http://adsabs.harvard.edu/abs/2015A%26A...576A.104P

Cite this

Collaboration, P., Ade, P. A. R., Aghanim, N., Alina, D., Alves, M. I. R., Armitage-Caplan, C., Arnaud, M., Arzoumanian, D., Ashdown, M., Atrio-Barandela, F., Aumont, J., Baccigalupi, C., Banday, A. J., Barreiro, R. B., Battaner, E., Benabed, K., Benoit-L√©vy, A., Bernard, J.-P., Bersanelli, M., ... Zonca, A. (2015). Planck intermediate results. XIX. An overview of the polarized thermal emission from Galactic dust. Astronomy and Astrophysics, 576. https://doi.org/10.1051/0004-6361/201424082

@article{b0ae04f19dcc453799ccff911c9ed7cd,

title = "Planck intermediate results. XIX. An overview of the polarized thermal emission from Galactic dust",

abstract = "This paper presents an overview of the polarized sky as seen by Planck HFI at 353 GHz, which is the most sensitive Planck channel for dust polarization. We construct and analyse maps of dust polarization fraction and polarization angle at 1¬∞ resolution, taking into account noise bias and possible systematic effects. The sensitivity of the Planck HFI polarization measurements allows for the first time a mapping of Galactic dust polarized emission on large scales, including low column density regions. We find that the maximum observed dust polarization fraction is high (pmax = 19.8%), in particular in some regions of moderate hydrogen column density (NH <2 √{\'o} 1021 cm-2). The polarization fraction displays a large scatter at NH below a few 1021 cm-2. There is a general decrease in the dust polarization fraction with increasing column density above NH ‚{\^a}{\'E} 1 √{\'o} 1021 cm-2 and in particular a sharp drop above NH ‚{\^a}{\'E} 1.5 √{\'o} 1022 cm-2. We characterize the spatial structure of the polarization angle using the angle dispersion function. We find that the polarization angle is ordered over extended areas of several square degrees, separated by filamentary structures of high angle dispersion function. These appear as interfaces where the sky projection of the magnetic field changes abruptly without variations in the column density. The polarization fraction is found to be anti-correlated with the dispersion of polarization angles. These results suggest that, at the resolution of 1¬∞, depolarization is due mainly to fluctuations in the magnetic field orientation along the line of sight, rather than to the loss of grain alignment in shielded regions. We also compare the polarization of thermal dust emission with that of synchrotron measured with Planck, low-frequency radio data, and Faraday rotation measurements toward extragalactic sources. These components bear resemblance along the Galactic plane and in some regions such as the Fan and North Polar Spur regions. The poor match observed in other regions shows, however, that dust, cosmic-ray electrons, and thermal electrons generally sample different parts of the line of sight. Appendices are available in electronic form at http://www.aanda.org",

keywords = "ISM: general, dust, extinction, ISM: magnetic fields, ISM:, clouds, submillimeter: ISM",

author = "Planck Collaboration and Ade, {P A R} and N Aghanim and D Alina and Alves, {M I R} and C Armitage-Caplan and M Arnaud and D Arzoumanian and M Ashdown and F Atrio-Barandela and J Aumont and C Baccigalupi and Banday, {A J} and Barreiro, {R B} and E Battaner and K Benabed and A Benoit-L√{\textcopyright}vy and J-P Bernard and M Bersanelli and P Bielewicz and Bock, {J J} and Bond, {J R} and J Borrill and Bouchet, {F R} and F Boulanger and A Bracco and C Burigana and Butler, {R C} and J-F Cardoso and A Catalano and A Chamballu and R-R Chary and Chiang, {H C} and Christensen, {P R} and S Colombi and Colombo, {L P L} and C Combet and F Couchot and A Coulais and Crill, {B P} and A Curto and F Cuttaia and L Danese and Davies, {R D} and Davis, {R J} and {de Bernardis}, P and {de Gouveia Dal Pino}, {E M} and {de Rosa}, A and {de Zotti}, G and J Delabrouille and F-X D√{\textcopyright}sert and C Dickinson and Diego, {J M} and S Donzelli and O Dor√{\textcopyright} and M Douspis and J Dunkley and X Dupac and G Efstathiou and En√{\"u}lin, {T A} and Eriksen, {H K} and E Falgarone and K Ferri√{\textregistered}re and F Finelli and O Forni and M Frailis and Fraisse, {A A} and E Franceschi and S Galeotta and K Ganga and T Ghosh and M Giard and Y Giraud-H√{\textcopyright}raud and J Gonz√°lez-Nuevo and G√≥rski, {K M} and A Gregorio and A Gruppuso and V Guillet and Hansen, {F K} and Harrison, {D L} and G Helou and C Hern√°ndez-Monteagudo and Hildebrandt, {S R} and E Hivon and M Hobson and Holmes, {W A} and A Hornstrup and Huffenberger, {K M} and Jaffe, {A H} and Jaffe, {T R} and Jones, {W C} and M Juvela and E Keih√§nen and R Keskitalo and Kisner, {T S} and R Kneissl and J Knoche and M Kunz and H Kurki-Suonio and G Lagache and A L√§hteenm√§ki and J-M Lamarre and A Lasenby and Lawrence, {C R} and Leahy, {J P} and R Leonardi and F Levrier and M Liguori and Lilje, {P B} and M Linden-V√∏rnle and M L√≥pez-Caniego and Lubin, {P M} and Mac√≠as-P√{\textcopyright}rez, {J F} and B Maffei and Magalh√£es, {A M} and D Maino and N Mandolesi and M Maris and Marshall, {D J} and Martin, {P G} and E Mart√≠nez-Gonz√°lez and S Masi and S Matarrese and P Mazzotta and A Melchiorri and L Mendes and A Mennella and M Migliaccio and M-A Miville-Desch√{\texttrademark}nes and A Moneti and L Montier and G Morgante and D Mortlock and D Munshi and Murphy, {J A} and P Naselsky and F Nati and P Natoli and Netterfield, {C B} and F Noviello and D Novikov and I Novikov and Oxborrow, {C A} and L Pagano and F Pajot and R Paladini and D Paoletti and F Pasian and Pearson, {T J} and O Perdereau and L Perotto and F Perrotta and F Piacentini and M Piat and D Pietrobon and S Plaszczynski and F Poidevin and E Pointecouteau and G Polenta and L Popa and Pratt, {G W} and S Prunet and J-L Puget and Rachen, {J P} and Reach, {W T} and R Rebolo and M Reinecke and M Remazeilles and C Renault and S Ricciardi and T Riller and I Ristorcelli and G Rocha and C Rosset and G Roudier and Rubi√±o-Mart√≠n, {J A} and B Rusholme and M Sandri and G Savini and D Scott and Spencer, {L D} and V Stolyarov and R Stompor and R Sudiwala and D Sutton and A-S Suur-Uski and J-F Sygnet and Tauber, {J A} and L Terenzi and L Toffolatti and M Tomasi and M Tristram and M Tucci and G Umana and L Valenziano and J Valiviita and {Van Tent}, B and P Vielva and F Villa and Wade, {L A} and Wandelt, {B D} and A Zacchei and A Zonca",

year = "2015",

month = apr,

doi = "10.1051/0004-6361/201424082",

language = "English",

volume = "576",

journal = "Astronomy and Astrophysics",

issn = "1432-0746",

publisher = "EDP Sciences",

}

Collaboration, P, Ade, PAR, Aghanim, N, Alina, D, Alves, MIR, Armitage-Caplan, C, Arnaud, M, Arzoumanian, D, Ashdown, M, Atrio-Barandela, F, Aumont, J, Baccigalupi, C, Banday, AJ, Barreiro, RB, Battaner, E, Benabed, K, Benoit-L√©vy, A, Bernard, J-P, Bersanelli, M, Bielewicz, P, Bock, JJ, Bond, JR, Borrill, J, Bouchet, FR, Boulanger, F, Bracco, A, Burigana, C, Butler, RC, Cardoso, J-F, Catalano, A, Chamballu, A, Chary, R-R, Chiang, HC, Christensen, PR, Colombi, S, Colombo, LPL, Combet, C, Couchot, F, Coulais, A, Crill, BP, Curto, A, Cuttaia, F, Danese, L, Davies, RD, Davis, RJ, de Bernardis, P, de Gouveia Dal Pino, EM, de Rosa, A, de Zotti, G, Delabrouille, J, D√©sert, F-X, Dickinson, C, Diego, JM, Donzelli, S, Dor√©, O, Douspis, M, Dunkley, J, Dupac, X, Efstathiou, G, En√ülin, TA, Eriksen, HK, Falgarone, E, Ferri√®re, K, Finelli, F, Forni, O, Frailis, M, Fraisse, AA, Franceschi, E, Galeotta, S, Ganga, K, Ghosh, T, Giard, M, Giraud-H√©raud, Y, Gonz√°lez-Nuevo, J, G√≥rski, KM, Gregorio, A, Gruppuso, A, Guillet, V, Hansen, FK, Harrison, DL, Helou, G, Hern√°ndez-Monteagudo, C, Hildebrandt, SR, Hivon, E, Hobson, M, Holmes, WA, Hornstrup, A, Huffenberger, KM, Jaffe, AH, Jaffe, TR, Jones, WC, Juvela, M, Keih√§nen, E, Keskitalo, R, Kisner, TS, Kneissl, R, Knoche, J, Kunz, M, Kurki-Suonio, H, Lagache, G, L√§hteenm√§ki, A, Lamarre, J-M, Lasenby, A, Lawrence, CR, Leahy, JP, Leonardi, R, Levrier, F, Liguori, M, Lilje, PB, Linden-V√∏rnle, M, L√≥pez-Caniego, M, Lubin, PM, Mac√≠as-P√©rez, JF, Maffei, B, Magalh√£es, AM, Maino, D, Mandolesi, N, Maris, M, Marshall, DJ, Martin, PG, Mart√≠nez-Gonz√°lez, E, Masi, S, Matarrese, S, Mazzotta, P, Melchiorri, A, Mendes, L, Mennella, A, Migliaccio, M, Miville-Desch√™nes, M-A, Moneti, A, Montier, L, Morgante, G, Mortlock, D, Munshi, D, Murphy, JA, Naselsky, P, Nati, F, Natoli, P, Netterfield, CB, Noviello, F, Novikov, D, Novikov, I, Oxborrow, CA, Pagano, L, Pajot, F, Paladini, R, Paoletti, D, Pasian, F, Pearson, TJ, Perdereau, O, Perotto, L, Perrotta, F, Piacentini, F, Piat, M, Pietrobon, D, Plaszczynski, S, Poidevin, F, Pointecouteau, E, Polenta, G, Popa, L, Pratt, GW, Prunet, S, Puget, J-L, Rachen, JP, Reach, WT, Rebolo, R, Reinecke, M, Remazeilles, M, Renault, C, Ricciardi, S, Riller, T, Ristorcelli, I, Rocha, G, Rosset, C, Roudier, G, Rubi√±o-Mart√≠n, JA, Rusholme, B, Sandri, M, Savini, G, Scott, D, Spencer, LD, Stolyarov, V, Stompor, R, Sudiwala, R, Sutton, D, Suur-Uski, A-S, Sygnet, J-F, Tauber, JA, Terenzi, L, Toffolatti, L, Tomasi, M, Tristram, M, Tucci, M, Umana, G, Valenziano, L, Valiviita, J, Van Tent, B, Vielva, P, Villa, F, Wade, LA, Wandelt, BD, Zacchei, A & Zonca, A 2015, 'Planck intermediate results. XIX. An overview of the polarized thermal emission from Galactic dust', Astronomy and Astrophysics, vol. 576. https://doi.org/10.1051/0004-6361/201424082

TY - JOUR

T1 - Planck intermediate results. XIX. An overview of the polarized thermal emission from Galactic dust

AU - Collaboration, Planck

AU - Ade, P A R

AU - Aghanim, N

AU - Alina, D

AU - Alves, M I R

AU - Armitage-Caplan, C

AU - Arnaud, M

AU - Arzoumanian, D

AU - Ashdown, M

AU - Atrio-Barandela, F

AU - Aumont, J

AU - Baccigalupi, C

AU - Banday, A J

AU - Barreiro, R B

AU - Battaner, E

AU - Benabed, K

AU - Benoit-L√©vy, A

AU - Bernard, J-P

AU - Bersanelli, M

AU - Bielewicz, P

AU - Bock, J J

AU - Bond, J R

AU - Borrill, J

AU - Bouchet, F R

AU - Boulanger, F

AU - Bracco, A

AU - Burigana, C

AU - Butler, R C

AU - Cardoso, J-F

AU - Catalano, A

AU - Chamballu, A

AU - Chary, R-R

AU - Chiang, H C

AU - Christensen, P R

AU - Colombi, S

AU - Colombo, L P L

AU - Combet, C

AU - Couchot, F

AU - Coulais, A

AU - Crill, B P

AU - Curto, A

AU - Cuttaia, F

AU - Danese, L

AU - Davies, R D

AU - Davis, R J

AU - de Bernardis, P

AU - de Gouveia Dal Pino, E M

AU - de Rosa, A

AU - de Zotti, G

AU - Delabrouille, J

AU - D√©sert, F-X

AU - Dickinson, C

AU - Diego, J M

AU - Donzelli, S

AU - Dor√©, O

AU - Douspis, M

AU - Dunkley, J

AU - Dupac, X

AU - Efstathiou, G

AU - En√ülin, T A

AU - Eriksen, H K

AU - Falgarone, E

AU - Ferri√®re, K

AU - Finelli, F

AU - Forni, O

AU - Frailis, M

AU - Fraisse, A A

AU - Franceschi, E

AU - Galeotta, S

AU - Ganga, K

AU - Ghosh, T

AU - Giard, M

AU - Giraud-H√©raud, Y

AU - Gonz√°lez-Nuevo, J

AU - G√≥rski, K M

AU - Gregorio, A

AU - Gruppuso, A

AU - Guillet, V

AU - Hansen, F K

AU - Harrison, D L

AU - Helou, G

AU - Hern√°ndez-Monteagudo, C

AU - Hildebrandt, S R

AU - Hivon, E

AU - Hobson, M

AU - Holmes, W A

AU - Hornstrup, A

AU - Huffenberger, K M

AU - Jaffe, A H

AU - Jaffe, T R

AU - Jones, W C

AU - Juvela, M

AU - Keih√§nen, E

AU - Keskitalo, R

AU - Kisner, T S

AU - Kneissl, R

AU - Knoche, J

AU - Kunz, M

AU - Kurki-Suonio, H

AU - Lagache, G

AU - L√§hteenm√§ki, A

AU - Lamarre, J-M

AU - Lasenby, A

AU - Lawrence, C R

AU - Leahy, J P

AU - Leonardi, R

AU - Levrier, F

AU - Liguori, M

AU - Lilje, P B

AU - Linden-V√∏rnle, M

AU - L√≥pez-Caniego, M

AU - Lubin, P M

AU - Mac√≠as-P√©rez, J F

AU - Maffei, B

AU - Magalh√£es, A M

AU - Maino, D

AU - Mandolesi, N

AU - Maris, M

AU - Marshall, D J

AU - Martin, P G

AU - Mart√≠nez-Gonz√°lez, E

AU - Masi, S

AU - Matarrese, S

AU - Mazzotta, P

AU - Melchiorri, A

AU - Mendes, L

AU - Mennella, A

AU - Migliaccio, M

AU - Miville-Desch√™nes, M-A

AU - Moneti, A

AU - Montier, L

AU - Morgante, G

AU - Mortlock, D

AU - Munshi, D

AU - Murphy, J A

AU - Naselsky, P

AU - Nati, F

AU - Natoli, P

AU - Netterfield, C B

AU - Noviello, F

AU - Novikov, D

AU - Novikov, I

AU - Oxborrow, C A

AU - Pagano, L

AU - Pajot, F

AU - Paladini, R

AU - Paoletti, D

AU - Pasian, F

AU - Pearson, T J

AU - Perdereau, O

AU - Perotto, L

AU - Perrotta, F

AU - Piacentini, F

AU - Piat, M

AU - Pietrobon, D

AU - Plaszczynski, S

AU - Poidevin, F

AU - Pointecouteau, E

AU - Polenta, G

AU - Popa, L

AU - Pratt, G W

AU - Prunet, S

AU - Puget, J-L

AU - Rachen, J P

AU - Reach, W T

AU - Rebolo, R

AU - Reinecke, M

AU - Remazeilles, M

AU - Renault, C

AU - Ricciardi, S

AU - Riller, T

AU - Ristorcelli, I

AU - Rocha, G

AU - Rosset, C

AU - Roudier, G

AU - Rubi√±o-Mart√≠n, J A

AU - Rusholme, B

AU - Sandri, M

AU - Savini, G

AU - Scott, D

AU - Spencer, L D

AU - Stolyarov, V

AU - Stompor, R

AU - Sudiwala, R

AU - Sutton, D

AU - Suur-Uski, A-S

AU - Sygnet, J-F

AU - Tauber, J A

AU - Terenzi, L

AU - Toffolatti, L

AU - Tomasi, M

AU - Tristram, M

AU - Tucci, M

AU - Umana, G

AU - Valenziano, L

AU - Valiviita, J

AU - Van Tent, B

AU - Vielva, P

AU - Villa, F

AU - Wade, L A

AU - Wandelt, B D

AU - Zacchei, A

AU - Zonca, A

PY - 2015/4

Y1 - 2015/4

N2 - This paper presents an overview of the polarized sky as seen by Planck HFI at 353 GHz, which is the most sensitive Planck channel for dust polarization. We construct and analyse maps of dust polarization fraction and polarization angle at 1¬∞ resolution, taking into account noise bias and possible systematic effects. The sensitivity of the Planck HFI polarization measurements allows for the first time a mapping of Galactic dust polarized emission on large scales, including low column density regions. We find that the maximum observed dust polarization fraction is high (pmax = 19.8%), in particular in some regions of moderate hydrogen column density (NH <2 √ó 1021 cm-2). The polarization fraction displays a large scatter at NH below a few 1021 cm-2. There is a general decrease in the dust polarization fraction with increasing column density above NH ‚âÉ 1 √ó 1021 cm-2 and in particular a sharp drop above NH ‚âÉ 1.5 √ó 1022 cm-2. We characterize the spatial structure of the polarization angle using the angle dispersion function. We find that the polarization angle is ordered over extended areas of several square degrees, separated by filamentary structures of high angle dispersion function. These appear as interfaces where the sky projection of the magnetic field changes abruptly without variations in the column density. The polarization fraction is found to be anti-correlated with the dispersion of polarization angles. These results suggest that, at the resolution of 1¬∞, depolarization is due mainly to fluctuations in the magnetic field orientation along the line of sight, rather than to the loss of grain alignment in shielded regions. We also compare the polarization of thermal dust emission with that of synchrotron measured with Planck, low-frequency radio data, and Faraday rotation measurements toward extragalactic sources. These components bear resemblance along the Galactic plane and in some regions such as the Fan and North Polar Spur regions. The poor match observed in other regions shows, however, that dust, cosmic-ray electrons, and thermal electrons generally sample different parts of the line of sight. Appendices are available in electronic form at http://www.aanda.org

AB - This paper presents an overview of the polarized sky as seen by Planck HFI at 353 GHz, which is the most sensitive Planck channel for dust polarization. We construct and analyse maps of dust polarization fraction and polarization angle at 1¬∞ resolution, taking into account noise bias and possible systematic effects. The sensitivity of the Planck HFI polarization measurements allows for the first time a mapping of Galactic dust polarized emission on large scales, including low column density regions. We find that the maximum observed dust polarization fraction is high (pmax = 19.8%), in particular in some regions of moderate hydrogen column density (NH <2 √ó 1021 cm-2). The polarization fraction displays a large scatter at NH below a few 1021 cm-2. There is a general decrease in the dust polarization fraction with increasing column density above NH ‚âÉ 1 √ó 1021 cm-2 and in particular a sharp drop above NH ‚âÉ 1.5 √ó 1022 cm-2. We characterize the spatial structure of the polarization angle using the angle dispersion function. We find that the polarization angle is ordered over extended areas of several square degrees, separated by filamentary structures of high angle dispersion function. These appear as interfaces where the sky projection of the magnetic field changes abruptly without variations in the column density. The polarization fraction is found to be anti-correlated with the dispersion of polarization angles. These results suggest that, at the resolution of 1¬∞, depolarization is due mainly to fluctuations in the magnetic field orientation along the line of sight, rather than to the loss of grain alignment in shielded regions. We also compare the polarization of thermal dust emission with that of synchrotron measured with Planck, low-frequency radio data, and Faraday rotation measurements toward extragalactic sources. These components bear resemblance along the Galactic plane and in some regions such as the Fan and North Polar Spur regions. The poor match observed in other regions shows, however, that dust, cosmic-ray electrons, and thermal electrons generally sample different parts of the line of sight. Appendices are available in electronic form at http://www.aanda.org

KW - ISM: general

KW - dust

KW - extinction

KW - ISM: magnetic fields

KW - ISM:

KW - clouds

KW - submillimeter: ISM

U2 - 10.1051/0004-6361/201424082

DO - 10.1051/0004-6361/201424082

M3 - Article

SN - 1432-0746

SN - 2329-1265

VL - 576

JO - Astronomy and Astrophysics

JF - Astronomy and Astrophysics

ER -

Planck intermediate results. XIX. An overview of the polarized thermal emission from Galactic dust

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