• Login
     
    View Item 
    •   ORFEO Home
    • Royal Belgian Institute for Space Aeronomy
    • BIRA-IASB publications
    • View Item
    •   ORFEO Home
    • Royal Belgian Institute for Space Aeronomy
    • BIRA-IASB publications
    • View Item
    JavaScript is disabled for your browser. Some features of this site may not work without it.

    Mapping extreme-scale alignments of quasar polarization vectors

    View/Open
    Hutsemekers(2005).pdf (1.188Mb)
    Authors
    Hutsemékers, D.
    Cabanac, R.
    Lamy, H.
    Sluse, D.
    Show allShow less
    Discipline
    Physical sciences
    Subject
    Cosmic rays
    Electromagnetic wave polarization
    Galaxies
    Magnetic fields
    Oscillations
    Vectors
    Cosmology: observations
    Dark matter
    Large scale structure of universe
    Quasars: general
    Astrophysics
    Audience
    Scientific
    Date
    2005
    Metadata
    Show full item record
    Description
    Based on a new sample of 355 quasars with significant optical polarization and using complementary statistical methods, we confirm that quasar polarization vectors are not randomly oriented over the sky with a probability often in excess of 99.9%. The polarization vectors appear coherently oriented or aligned over huge (∼ 1 Gpc) regions of the sky located at both low (z ∼ 0.5) and high (z ∼ 1.5) redshifts and characterized by different preferred directions of the quasar polarization. In fact, there seems to exist a regular alternance along the line of sight of regions of randomly and aligned polarization vectors with a typical comoving length scale of 1.5 Gpc. Furthermore, the mean polarization angle θ̄ appears to rotate with redshift at the rate of ∼30° per Gpc. The symmetry of the the θ̄ - z relation is mirror-like, the mean polarization angle rotating clockwise with increasing redshift in North Galactic hemisphere and counter-clockwise in the South Galactic one. These characteristics make the alignment effect difficult to explain in terms of local mechanisms, namely a contamination by interstellar polarization in our Galaxy. While interpretations like a global rotation of the Universe can potentially explain the effect, the properties we observe qualitatively correspond to the dichroism and birefringence predicted by photon-pseudoscalar oscillation within a magnetic field. Interestingly, the alignment effect seems to be prominent along an axis not far from preferred directions tentatively identified in the Cosmic Microwave Background maps. Although many questions and more particularly the interpretation of the effect remain open, alignments of quasar polarization vectors appear as a promising new way to probe the Universe and its dark components at extremely large scales.
    Citation
    Hutsemékers, D.; Cabanac, R.; Lamy, H.; Sluse, D. (2005). Mapping extreme-scale alignments of quasar polarization vectors. , Astronomy and Astrophysics, Vol. 441, Issue 3, 915-930, DOI: 10.1051/0004-6361:20053337.
    Identifiers
    uri: https://orfeo.belnet.be/handle/internal/4607
    doi: http://dx.doi.org/10.1051/0004-6361:20053337
    scopus: 2-s2.0-26844564671
    Type
    Article
    Peer-Review
    Yes
    Language
    eng
    Links
    NewsHelpdeskBELSPO OA Policy

    Browse

    All of ORFEOCommunities & CollectionsBy Issue DateAuthorsTitlesDisciplinesThis CollectionBy Issue DateAuthorsTitlesDisciplines
     

    DSpace software copyright © 2002-2016  DuraSpace
    Send Feedback | Cookie Information
    Theme by 
    Atmire NV