Alex Lazarian (UW-Madison): New Ways to Study Magnetic Fields
Seminar | March 3 | 12:10-1 p.m. | 131 Campbell Hall
Alex Lazarian, University of Wisconsin-Madison
I shall introduce two new techniques of magnetic field tracing. The first one uses Doppler-shifted emission lines and employs the gradients of velocity centroids in order to trace magnetic fields in the diffuse interstellar media as well as to trace regions of star formation associated with the gravitational collapse. I shall provide the theoretical justification of the use of the measure, its numerical testing as well as the comparison of the directions obtained with the velocity centroid gradients using GALFA HI data and those of magnetic field as traced by Planck. The second measure is the synchrotron intensity gradients that also trace magnetic field and, unlike synchrotron polarization, are insensitive to Faraday rotation. I shall also show its correspondence with the magnetic field tracing by Planck and discuss the synergy of using it with low frequency polarization studies. I shall discuss the promise of the new techniques both for the star formation and CMB foreground studies.