Snakes in the Plane: Direct Imaging of Magnetized Turbulence in the Interstellar Medium

Type Conference Paper
Names Bryan M. Gaensler, M. Haverkorn, B. Burkhart, K. J. Newton-McGee, R. D. Ekers, A. Lazarian, N. M. McClure-Griffiths, T. Robishaw, J. M. Dickey, A. J. Green
Proceedings Title Bulletin of the American Astronomical Society
Conference Name American Astronomical Society, AAS Meeting #219, #349.04
Date January 1, 2012
Short Title Snakes in the Plane
Library Catalog NASA ADS
Abstract The interstellar medium (ISM) of the Milky Way consists of gas and dust at a range of temperatures and pressures, and provides the raw material from which stars and planets form. Astronomers have developed a sophisticated understanding of the ISM as a multi-phase, magnetized, turbulent medium. However, observations have lacked the sensitivity and resolution to directly image the small-scale structure associated with turbulent motions in the diffuse ISM. Radio polarimetry is a promising avenue for further progress, because Faraday rotation of linearly polarized radio signals provides a very sensitive probe of fluctuations in magnetic field and ionized gas density. Here we present a new way of processing images of linearly polarized radio emission from the ISM, in which we derive the gradient of the Stokes vector (Q,U). This provides the first direct image of supersonic turbulence in the ISM, manifested as a complex filamentary web of sharp density jumps. Application of the polarization gradient to both simulations and observations can allow the measurement of currently unconstrained parameters of interstellar turbulence such as the Mach number, Reynolds number and magnetic field strength.
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