Velocity coordinate spectrum: geometrical aspects of observations

2006/11/15 by A. V. Chepurnov, A. Lazarian, Chepurnov, A. +1 · 1 citation
Physics and Astronomy · #Astrophysics (astro-ph) #FOS: Physical sciences #Stellar, planetary, and galactic studies

paper · pdf · doi:10.48550/arxiv.astro-ph/0611465

openalex publication_date 2006/11/15 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28

Abstract

We analyze a technique of obtaining turbulence power spectrum using spectral line data along the velocity coordinate, which we refer to as Velocity Coordinate Spectrum (VCS). We formalize geometrical aspects of observation through a single factor, "geometric term". We find that all variety of particular observational configurations can be described using correspondent variants of this term, which we explicitly calculate. This allows us to obtain asymptotics for both parallel lines of sight and crossing lines of sight. The latter case is especially important for studies of turbulence within diffuse ISM in Milky Way. For verification of our results, we use direct calculation of VCS spectra, while the numerical simulations are presented in a companion paper.

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