Magnetic Field Lines in M51

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About this Image

The total radio continuum emission from the "whirlpool" galaxy M51 (distance estimates range between 13 and 30 million light years) is strongest at the inner edges of the optical spiral arms, probably due to the compression of magnetic fields by density waves. The vectors give the orientations of the regular magnetic fields as derived from the polarized emission. The field lines follow nicely the optical spiral arms. Unexpectedly, strong polarized emission is observed also between the optical arms which indicates the action of a dynamo. This image was observed with the VLA in its most compact configuration at 6cm radio wavelength (broadband continuum). As the VLA cannot detect the diffuse, large-scale radio emission, data from the Effelsberg 100-m telescope in Germany at the same wavelength was added.

Investigator(s):  Rainer Beck (MPIfR Bonn, Germany), Cathy Horellou (Onsala Space

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Technical Data

    Telescope VLA 
    Date of Observation 1991-04-00 
    Type of Observation Continuum Observations 
    Band C 
    Wavelength 6 cm 
    Frequency 5.0 GHz 
    Center of Image RA: 13:29:52.37, Dec: 47:11:40.80 (J2000)  
    Field of View 0.1667 x 0.2000 degrees  
    Technical Caption VLA in D-array. VLA observations made 1991 March 23 and 1991 April 1; Effelsberg observations made summer 1996. VLA resolution 15\"; data from Effelsberg adds 2.5 minutes of arc.  

  • Astronomical database entries for M51
    • Query NED for images of M51
    • Query SIMBAD for more M51 data


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