Amazing Milky Way Magnetic Fingerprint by Planck

By James Anderson •  Updated: 05/06/14 •  4 min read

A team of astrophysicists has created a unique map of the sky that shows the magnetic field shaping the Milky Way galaxy, using data from the Planck Space Telescope. The image will help open doors to understand the birth of the universe.

“Just as the Earth has a magnetic field, our galaxy has a large-scale magnetic field — albeit 100,000 times weaker than the magnetic field at the Earth’s surface. And just as the Earth’s magnetic field generates phenomena such as the aurorae, our galaxy’s magnetic field is important for many phenomena within it.”

“And now. Planck has given us the most detailed picture of it yet,”

says Douglas Scott, University of British Columbia astrophysicist.

Planck High-Frequency Instrument

Milky Way galaxy Planck

The magnetic field of our Milky Way galaxy as seen by the Planck satellite. Credit: ESA and the Planck Collaboration

The Planck telescope has, since 2009, been charting the Cosmic Microwave Background, which is the light from the Universe only 380,000 years after the Big Bang.

Planck additionally observes light from much closer space than the farthest reaches of time and space.

With its High-Frequency Instrument, Planck senses the light from microscopic dust particles in our galaxy. It helps discover the non-random direction in which the light waves vibrate, called polarization. It is this polarized light that indicates the orientation of the field lines.

“Dust is often overlooked but it contains the stuff from which terrestrial planets and life form. So by probing the dust, Planck helps us understand the complex history of the galaxy as well as the life within it,”

says the Canadian Institute for Theoretical Astrophysics’ Prof. Peter Martin.

Detailed Investigation of the Early Cosmos

The collaborative team includes researchers from the University of British Columbia and the Canadian Institute for Theoretical Astrophysics at the University of Toronto.

Scientists from the Planck collaboration will release data later in 2014 that should enable astronomers to separate with great confidence any possible foreground signal from our Galaxy from the polarized and tenuous primordial signal from the Cosmic Microwave Background.

Scientists from the BICEP2 collaboration claimed in March 2014 the first detection of such a signal.

The Planck team’s data will allow a much more detailed investigation of the early history of the cosmos, from the accelerated expansion when the Universe was much less than one second old to the period when the first stars were born, several hundred million years later.

“These results help us lift the veil of emissions from these tiny but pervasive Galactic dust grains which obscure a Planck goal of peering into the earliest moments of the Big Bang to find evidence for gravitational waves created in that epoch, as reported by BICEP2,”

according to Prof. J. Richard Bond.

Studies:

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-Lévy, 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. Désert, C. Dickinson, J. M. Diego, S. Donzelli, O. Doré, M. Douspis, et al.
Planck intermediate results. XIX. An overview of the polarized thermal emission from Galactic dust. Astronomy & Astrophysics, 2014

Planck Collaboration: P. A. R. Ade, N. Aghanim, M. I. R. Alves, G. Aniano, 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-Lévy, J.-P. Bernard, M. Bersanelli, P. Bielewicz, J. R. Bond, J. Borrill, F. R. Bouchet, F. Boulanger, A. Bracco, C. Burigana, J.-F. Cardoso, A. Catalano, A. Chamballu, 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, A. de Rosa, G. de Zotti, J. Delabrouille, C. Dickinson, J. M. Diego, S. Donzelli, O. Doré, M. Douspis, X. Dupac, T. A. Enßlin, H. K. Eriksen, E. Falgarone, L. Fanciullo, K. Ferrière, et al.
Planck intermediate results. XX. Comparison of polarized thermal emission from Galactic dust with simulations of MHD turbulence.
Astronomy & Astrophysics, 2014

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