Velocity centroid gradients for absorbing media

Abstract

We explore how the velocity gradient technique (VGT) can be applied to absorbing media in the case of${}^{13}$CO 2-1 emission. The VGT is a new way to trace magnetic fields in the plane of the sky using only spectroscopic observations. We apply the VGT to magnetohydrodynamic turbulence simulations that have been post-processed to include ${}^{13}$CO 2-1 emission and we calculate the velocity centroid gradients. We find that the velocity centroid gradients trace the projected magnetic field in media with different ${}^{13}$CO abundances, densities and optical depths. Our study opens up the possibility of using velocity centroid gradients to trace magnetic fields in molecular clouds using 13CO emission.

8 pages , 6 figures, MNRAS published Bibcode: 2019MNRAS.483.1287G

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Cited by in corpus (7)

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• Predictions of Cosmic Microwave Background Foregrounds Dust Polarization Using Velocity Gradients
• Mapping of the structure of the galactic magnetic field with velocity gradients: Test using star light polarization
• A Synergy of the Velocity Gradients Technique and the Probability Density Functions for Identifying Gravitational Collapse in Self-Absorbing Media