Tracing interstellar magnetic field using the velocity gradient technique in shock and self-gravitating media

Abstract

This study proceeds with the development of the technique employing velocity gradients that were identified in (\cite{GL17}, henceforth GL17) as a means of probing magnetic field in interstellar media. We demonstrate a number of practical ways on improving the accuracy of tracing magnetic fields in diffuse interstellar media using velocity centroid gradients (VCGs). Addressing the magnetic field tracing in super-Alfvenic turbulence we introduce the procedure of filtering low spatial frequencies, that enables magnetic field tracing in the situations when the kinetic energy of turbulent plasmas dominate its magnetic energy. We propose the synergic way of of using VCGs together with intensity gradients (IGs), synchrotron intensity gradients (SIGs) as well as dust polarimetry. We show that while the IGs trace magnetic field worse than the VCGs, the deviations of the angle between the IGs and VCGs trace the shocks in diffuse media. Similarly the perpendicular orientation of the VCGs and the SIGs or to the dust polarimetry data trace the regions of gravitational collapse. We demonstrate the utility of combining the VCGs, IGs and polarimetry using GALFA HI and Planck polarimetry data. We also provide an example of synergy of the VCGs and the SIGs using the HI4PI full-sky HI survey together with the Planck synchrotron intensity data.

15 pages, 15 figures, submitted to ApJ

References in corpus (4)

• Tracing magnetic fields with spectroscopic channel maps
• On the relation between the column density structures and the magnetic field orientation in the Vela C molecular complex
• Tracing interstellar magnetic field using velocity gradient technique: Application to Atomic Hydrogen data
• Effects of dust absorption on spectroscopic studies of turbulence

Cited by in corpus (13)

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• Magnetic field fluctuations in anisotropic, supersonic turbulence
• Revealing Gravitational Collapse in Serpens G3-G6 Molecular Cloud using Velocity Gradients
• Technique for separating velocity and density contributions in spectroscopic data and its application to studying turbulence and magnetic fields
• Anisotropies in Compressible MHD Turbulence: Probing Magnetic Fields and Measuring Magnetization
• Curvature of magnetic field lines in compressible magnetized turbulence: Statistics, magnetization predictions, gradient curvature, modes and self-gravitating media
• Tracing magnetic field morphology using the Velocity Gradient Technique in the presence of CO self-absorption
• Study Turbulence and Probe Magnetic Field Using Gradients Technique: Application to HI-to-H2 Transition Regions
• Velocity Gradients: Magnetic Field Tomography towards the Supernova Remnant W44
• Large-scale magnetic field in the Monoceros OB-1 East molecular cloud
• Comment on Clark et al. (2019) "The Physical Nature of Neutral Hydrogen Intensity Structure"
• Anomalous compressible mode generation by global frame projections of pure Alfven mode
• Velocity centroid gradients for absorbing media