Abstract: Modern understanding of MHD turbulence suggests that this type of turbulence is strongly anisotropic at small scales. Due to turbulent fast reconnection turbulent eddies are aligned with the magnetic field surrounding the eddies. This entails a conclusion that gradients of velocity and magnetic field are perpendicular to the local direction of the magnetic field. Guided by this fact we proposed, developed and successfully tested with observational data a set of new techniques for studying interstellar magnetic fields. I shall demonstrate how the velocity gradients can be measured using either velocity centroids of thin channel spectroscopic maps, while magnetic field gradients can be measured using synchrotron intensity or synchrotron polarization. I shall present 3D maps of galactic magnetic fields obtained with the new technique, demonstrate that gradients can provide both magnetic field tracing and identify the regions of gravitational collapse using observations of molecular clouds. I shall discuss new ways of obtaining magnetic field strength using the gradients. I shall show how to use different types of gradients to map the structure of the magnetic web within the multiphase interstellar media.
Prof.Alexandre Lazarian's research deals with magnetohydrodynamic turbulence. He is a professor of Astronomy and Physics at Wisconsin-Madison University. His major research topics include magnetic reconnection, properties of magnetized turbulence at various scales and regimes, acceleration and propagation of cosmic rays, techniques to observational studies of astrophysical turbulence . He has published more than 270 SCI papers, the H-index for NASA ADS is 68, for Google Scholar 72.
Awards and recognition: Institut2017 KASI (Korea) Distinguished Visitor Fellowship; 2014 International Leading Researcher Award (Brazil); 2014 Continues Collaboration award (from Humboldt Award 2010); 2013 Fellow of American Physical Society , and a number of other awards and fellowships.