Magnetically aligned straight depolarization canals and the rolling Hough transform

Scientific paper - Letter

• Author: Vibor Jelić
• Author: David Prelogović
• Author: Marijke Haverkorn
• Author: Jur Remeijn
• Author: Dora Klindžić
• Author's institution: University of Zagreb; Faculty of Science; (Department of Physics)
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Physics

Abstract (english)

Aims. We aim to characterize the properties of the straight depolarization canals detected in the Low Frequency Array (LOFAR) polarimetric observations of a field centered on the extragalactic source 3C 196. We also compare the canal orientations with magnetically aligned HI filaments and the magnetic field probed by polarized dust emission. Methods. We used the rolling Hough transform (RHT) to identify and characterize the orientation of the straight depolarization canals in radio polarimetric data and the filaments in HI data. Results. The majority of the straight depolarization canals and the Hi filaments are inclined by ~10° with respect to the Galactic plane and are aligned with the plane-of-sky magnetic field orientation probed by the Planck dust polarization data. The other distinct orientation, of −65° with respect to the Galactic plane, is associated with the orientation of a bar-like structure observed in the 3C 196 field at 350 MHz. Conclusions. An alignment between three distinct tracers of the (local) interstellar medium (ISM) suggests that an ordered magnetic field plays a crucial role in confining different ISM phases. The majority of the straight depolarization canals are a result of a projection of the complicated 3D distribution of the ISM. The RHT analysis is a robust method for identifying and characterizing the straight depolarization canals observed in radio-polarimetric data.

• Keywords (english): ISM: general; ISM: magnetic fields; ISM: structure; radio continuum: ISM; techniques: interferometric; techniques: polarimetric
• Language: english
• Publication type: Scientific paper - Letter
• Publication status: Published
• Peer review: Peer review - international
• Publication version: Published version
• Journal title: Astronomy & Astrophysics
• Numbering: vol. 615, L3
• p-ISSN: 0004-6361
• e-ISSN: 1432-0746
• DOI: https://doi.org/10.1051/0004-6361/201833291
• URN:NBN: urn:nbn:hr:217:334343
• Publication: 2018-07-10
• Document URL: https://www.aanda.org/10.1051/0004-6361/201833291
• Type of resource: Text
• Access conditions: Open access
• Public note: © ESO 2018. Received: 24 April 2018. Accepted: 14 June 2018. Published online 10 July 2018.
• Created on: 2024-09-29 20:05:20