“School of Astronomy”

Back to Papers Home
Back to Papers of School of Astronomy

Paper   IPM / Astronomy / 16100
School of Astronomy
  Title:   The Magnetized Disk-Halo Transition Region of M51
1.  M. Kierdorf
2.  S. A. Mao
3.  A. Fletcher
4.  R. Beck
5.  M. Haverkorn
6.  A. Basu
7.  F. Tabatabaei
8.  J. Ott
  Status:   Published
  Journal: IAU
  Vol.:  14
  Year:  2020
  Pages:   319-322
  Supported by:            ipm IPM
An excellent laboratory for studying large scale magnetic fields is the grand de- sign face-on spiral galaxy M51. Due to wavelength-dependent Faraday depolarization, linearly polarized synchrotron emission at different radio frequencies gives a picture of the galaxy at different depths: Observations at L-band (1-2 GHz) probe the halo region while at C- and X- band (4-8 GHz) the linearly polarized emission probe the disk region of M51. We present new observations of M51 using the Karl G. Jansky Very Large Array (VLA) at S-band (2-4 GHz), where previously no polarization observations existed, to shed new light on the transition region between the disk and the halo. We discuss a model of the depolarization of synchrotron radiation in a multilayer magneto-ionic medium and compare the model predictions to the multi-frequency polarization data of M51 between 1-8GHz. The new S-band data are essential to distinguish between different models. Our study shows that the initial model parameters, i.e. the total reg- ular and turbulent magnetic field strengths in the disk and halo of M51, need to be adjusted to successfully fit the models to the data.

Download TeX format
back to top
scroll left or right