New model of the coherent magnetic halo of the Milky Way

Recent catalog of Faraday rotation measures (RM) of extragalactic sources together with the synchrotron polarization data from WMAP and Planck provide us with the wealth of information on the Galactic magnetic field (GMF). In this talk, we will present a new model of the regular GMF outside of the thin disk. The model is based on several phenomenological components of the GMF -- the spiral arms, the toroidal halo, the X-shaped field and the compressed field of the Local Bubble wall. We found that the four components listed above are sufficient to fit both the RM and polarization data over the whole sky with only a small fraction masked out. Our model for the first time takes into account our location inside of the Local Bubble. We show that the Local Bubble wall might be responsible for about 50% of the polarized synchrotron intensity at high Galactic latitudes and so our model does not require introduction of striated fields. Also, we show that the Fan Region can be modeled as a Galactic-scale feature. The pitch angle of the magnetic field in our fit converged to the value around 20 degrees. Interestingly, with value is very close to the direction of arms inferred recently from Gaia data.


Mardi, 10 septembre, 2024 - 14:00 to 15:00

Localisation / Location: 


Salle / Local: 

  • Séminaire

Nom/Prénom // Last name/First name: 

Alexander Korochkin


ULB, Bruxelles

Equipe(s) organisatrice(s) / Organizing team(s): 

  • Théorie

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