Dust-polarization Maps and Interstellar Turbulence

被引:42
作者
Caldwell, Robert R. [1 ]
Hirata, Chris [2 ]
Kamionkowski, Marc [3 ]
机构
[1] Dartmouth Coll, Dept Phys & Astron, 6127 Wilder Lab, Hanover, NH 03755 USA
[2] Ohio State Univ, Ctr Cosmol & Astroparticle Phys, 191 West Woodruff Lane, Columbus, OH 43210 USA
[3] Johns Hopkins Univ, Dept Phys & Astron, 3400 North Charles St, Baltimore, MD 21218 USA
关键词
ISM: general; cosmic background radiation; GALACTIC MAGNETIC-FIELD; THERMAL EMISSION; RADIATIVE TORQUES; MHD TURBULENCE; GRAVITY-WAVES; B-MODES; SUBMILLIMETER; SIMULATIONS; ORIENTATION; ANISOTROPY;
D O I
10.3847/1538-4357/aa679c
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
Perhaps the most intriguing result of Planck's dust-polarization measurements is the observation that the power in the E-mode polarization is twice that in the B mode, as opposed to pre-Planck expectations of roughly equal dust powers in the E. and B modes. Here we show how the E-and B-mode powers depend on the detailed properties of the fluctuations in the magnetized interstellar medium (ISM). These fluctuations can be decomposed into slow, fast, and Alfven magnetohydrodynamic (MHD) waves, which comprise a complete basis that can be used to describe linear fluctuations of a magnetized fluid. They can alternatively be decomposed in terms of one longitudinal and two transverse components of a fluid-displacement field. The intensity (T) and E-and B-mode amplitudes induced by each of the three types of waves, in both decompositions, are then calculated. To illustrate how these tools can be applied, we consider a toy model of the ISM in which dust traces a single component of plasma, and obtain the EE/BB ratio and TE correlation for several ansatzes for the power in slow/fast/Alfven waves and in longitudinal/transverse waves. Although our model may be too simplistic to properly describe the nonlinear structure of interstellar magnetic fields, we find that the observed EE/BB ratio (and its scale invariance) and positive TE correlation-as well as the observed power-law index for the angular spectrum of these fluctuations-are not easily accommodated in terms of simple MHD turbulence prescriptions for the expected powers in slow, fast, and Alfven waves. We speculate that the similar to 0.1-30. pc length scales probed by these dust-polarization measurements are not described by MHD turbulence, but rather probe the large-scale physics that drives ISM turbulence. We find that a slightly anisotropic spectrum of random fluid displacements produces EE/BB similar or equal to 2 and a positive TE crosscorrelation. Furthermore, we find that large EE/BB and positive TE are due primarily to longitudinal, rather than transverse, modes in the random-displacement field, providing, perhaps, some clue to the mechanism that stirs the ISM. Future investigations involving the spatial dependence of the EE/BB ratio, TE correlation, and local departures from statistical isotropy in dust-polarization maps, as well as further tests of some of the assumptions in this analysis, are outlined. This work may also aid in the improvement of foreground-separation techniques for studies of cosmic microwave background polarization.
引用
收藏
页数:12
相关论文
共 78 条
[1]   Planck intermediate results XXXII. The relative orientation between the magnetic field and structures traced by interstellar dust [J].
Adam, R. ;
Ade, P. A. R. ;
Aghanim, N. ;
Alves, M. I. R. ;
Arnaud, M. ;
Arzoumanian, D. ;
Ashdown, M. ;
Aumont, J. ;
Baccigalupi, C. ;
Banday, A. J. ;
Barreiro, R. B. ;
Bartolo, N. ;
Battaner, E. ;
Benabed, K. ;
Benoit-Levy, A. ;
Bernard, J-P. ;
Bersanelli, M. ;
Bielewicz, P. ;
Bonaldi, A. ;
Bonavera, L. ;
Bond, J. R. ;
Borrill, J. ;
Bouchet, F. R. ;
Boulanger, F. ;
Bracco, A. ;
Burigana, C. ;
Butler, R. C. ;
Calabrese, E. ;
Cardoso, J-F ;
Catalano, A. ;
Chamballu, A. ;
Chiang, H. C. ;
Christensen, P. R. ;
Colombi, S. ;
Colombo, L. P. L. ;
Combet, C. ;
Couchot, F. ;
Crill, B. P. ;
Curto, A. ;
Cuttaia, F. ;
Danese, L. ;
Davies, R. D. ;
Davis, R. J. ;
de Bernardis, P. ;
de Rosa, A. ;
de Zotti, G. ;
Delabrouillel, J. ;
Dickinson, C. ;
Diego, J. M. ;
Dole, H. .
ASTRONOMY & ASTROPHYSICS, 2016, 586
[2]  
Adam R., 2016, AA, V586, pA133, DOI [DOI 10.1051/0004-6361/201425034, 10.1051/0004-6361/201425034]
[3]   Planck intermediate results XXXVIII. E- and B-modes of dust polarization from the magnetized filamentary structure of the interstellar medium [J].
Ade, P. A. R. ;
Aghanim, N. ;
Arnaud, M. ;
Ashdown, M. ;
Aumont, J. ;
Baccigalupi, C. ;
Banday, A. J. ;
Barreiro, R. B. ;
Bartolo, N. ;
Battaner, E. ;
Benabed, K. ;
Benoit-Levy, A. ;
Bernard, J-P. ;
Bersanelli, M. ;
Bielewicz, P. ;
Bonaldi, A. ;
Bonavera, L. ;
Bond, J. R. ;
Borrill, J. ;
Bouchet, F. R. ;
Boulanger, F. ;
Bracco, A. ;
Burigana, C. ;
Calabrese, E. ;
Cardoso, J-F. ;
Catalano, A. ;
Chamballu, A. ;
Chary, R-R. ;
Chiang, H. C. ;
Christensen, P. R. ;
Colombo, L. P. L. ;
Combet, C. ;
Cri, B. P. ;
Curto, A. ;
Cuttaia, F. ;
Danese, L. ;
Davies, R. D. ;
Davis, R. J. ;
De Bernardis, P. ;
de Rosa, A. ;
de Zotti, G. ;
Delabrouille, J. ;
Delouis, J-M. ;
Dickinson, C. ;
Diego, J. M. ;
Dole, H. ;
Donzelli, S. ;
Dore, O. ;
Douspis, M. ;
Dunkley, J. .
ASTRONOMY & ASTROPHYSICS, 2016, 586
[4]   Planck intermediate results. XIX. An overview of the polarized thermal emission from Galactic dust [J].
Ade, P. A. R. ;
Aghanim, N. ;
Alina, D. ;
Alves, M. I. R. ;
Armitage-Caplan, C. ;
Amaue, M. ;
Arzoumanian, D. ;
Ashdown, M. ;
Atrio-Barandela, F. ;
Aumont, J. ;
Baccigalupi, C. ;
Banda, A. J. ;
Barreiro, R. B. ;
Battaner, E. ;
Benabed, K. ;
Benoit-Levy, A. ;
Bernard, J. -P. ;
Bersanelli, M. ;
Bielewicz, P. ;
Bock, J. J. ;
Bond, J. R. ;
Borrill, J. ;
Bouchet, F. R. ;
Boulanger, F. ;
Bracco, A. ;
Burigana, C. ;
Butler, R. C. ;
Cardoso, J. -F. ;
Catalano, A. ;
Chamballu, A. ;
Chary, R. -R. ;
Chiang, H. C. ;
Christensen, P. R. ;
Colombi, S. ;
Colombo, L. P. L. ;
Combet, C. ;
Couchot, F. ;
Coulais, A. ;
Crill, B. P. ;
Curto, A. ;
Cuttaia, E. ;
Danese, L. ;
Davies, R. D. ;
Davis, R. J. ;
de Bernardis, P. ;
de Gouveia Dal Pino, E. M. ;
De Rosa, A. ;
de Zotti, G. ;
Delabrouille, J. ;
Desert, F. -X. .
ASTRONOMY & ASTROPHYSICS, 2015, 576
[5]   Planck intermediate results. XXII. Frequency dependence of thermal emission from Galactic dust in intensity and polarization [J].
Ade, P. A. R. ;
Alves, M. I. R. ;
Aniano, G. ;
Armitage-Caplan, C. ;
Arnaud, M. ;
Atrio-Barandela, F. ;
Aumont, J. ;
Baccigalupi, C. ;
Banday, A. J. ;
Barreiro, R. B. ;
Battaner, E. ;
Benabed, K. ;
Benoit-Levy, A. ;
Bernard, J. -P. ;
Bersanelli, M. ;
Bielewicz, P. ;
Bock, J. J. ;
Bond, J. R. ;
Borrill, J. ;
Bouchet, F. R. ;
Boulanger, F. ;
Burigana, C. ;
Cardoso, J. -F. ;
Catalano, A. ;
Chamballu, A. ;
Chiang, H. C. ;
Colombo, L. P. L. ;
Combet, C. ;
Couchot, F. ;
Coulais, A. ;
Crill, B. P. ;
Curto, A. ;
Cuttaia, F. ;
Danese, L. ;
Davies, R. D. ;
Davis, R. J. ;
de Bernardis, P. ;
de Zotti, G. ;
Delabrouille, J. ;
Desert, F. -X. ;
Dickinson, C. ;
Diego, J. M. ;
Donzelli, S. ;
Dore, O. ;
Douspis, M. ;
Dunkley, J. ;
Dupac, X. ;
Ensslin, T. A. ;
Eriksen, H. K. ;
Falgarone, E. .
ASTRONOMY & ASTROPHYSICS, 2015, 576
[6]   Planck 2013 results. XVI. Cosmological parameters [J].
Ade, P. A. R. ;
Aghanim, N. ;
Armitage-Caplan, C. ;
Arnaud, M. ;
Ashdown, M. ;
Atrio-Barandela, F. ;
Aumont, J. ;
Baccigalupi, C. ;
Banday, A. J. ;
Barreiro, R. B. ;
Bartlett, J. G. ;
Battaner, E. ;
Benabed, K. ;
Benoit, A. ;
Benoit-Levy, A. ;
Bernard, J. -P. ;
Bersanelli, M. ;
Bielewicz, P. ;
Bobin, J. ;
Bock, J. J. ;
Bonaldi, A. ;
Bond, J. R. ;
Borrill, J. ;
Bouchet, F. R. ;
Bridges, M. ;
Bucher, M. ;
Burigana, C. ;
Butler, R. C. ;
Calabrese, E. ;
Cappellini, B. ;
Cardoso, J. -F. ;
Catalano, A. ;
Challinor, A. ;
Chamballu, A. ;
Chary, R. -R. ;
Chen, X. ;
Chiang, H. C. ;
Chiang, L. -Y ;
Christensen, P. R. ;
Church, S. ;
Clements, D. L. ;
Colombi, S. ;
Colombo, L. P. L. ;
Couchot, F. ;
Coulais, A. ;
Crill, B. P. ;
Curto, A. ;
Cuttaia, F. ;
Danese, L. ;
Davies, R. D. .
ASTRONOMY & ASTROPHYSICS, 2014, 571
[7]  
Ade P. A. R., 2015, ASTRON ASTROPHYS, V594, pA25
[8]  
Aghanim N., 2016, AA, V596, pA105, DOI DOI 10.1051/0004-6361/201628636
[9]   A refined model for spinning dust radiation [J].
Ali-Haiemoud, Yacine ;
Hirata, Christopher M. ;
Dickinson, Clive .
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 2009, 395 (02) :1055-1078
[10]   Interstellar Dust Grain Alignment [J].
Andersson, B-G ;
Lazarian, A. ;
Vaillancourt, John E. .
ANNUAL REVIEW OF ASTRONOMY AND ASTROPHYSICS, VOL 53, 2015, 53 :501-539