An observational method to measure the relative fractions of solenoidal and compressible modes in interstellar clouds
Abstract
We introduce a new method for observationally estimating the fraction of momentum density (ρv) power contained in solenoidal modes (for which ∇ · ρv = 0) in molecular clouds. The method is successfully tested with numerical simulations of supersonic turbulence that produce the full range of possible solenoidal/compressible fractions. At present, the method assumes statistical isotropy, and does not account for anisotropies caused by (e.g.) magnetic fields. We also introduce a framework for statistically describing density-velocity correlations in turbulent clouds.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- August 2014
- DOI:
- 10.1093/mnras/stu888
- arXiv:
- arXiv:1405.1285
- Bibcode:
- 2014MNRAS.442.1451B
- Keywords:
-
- turbulence;
- methods: statistical;
- ISM: clouds;
- ISM: kinematics and dynamics;
- Astrophysics - Astrophysics of Galaxies
- E-Print:
- 20 pages, 13 figures, accepted for publication in MNRAS