Turbulence in simulated H II regions
2014 (English)In: Monthly notices of the Royal Astronomical Society, ISSN 0035-8711, E-ISSN 1365-2966, Vol. 445, no 2, 1797-1819 p.Article in journal (Refereed) Published
We investigate the scale dependence of fluctuations inside a realistic model of an evolving turbulent H II region and to what extent these may be studied observationally. We find that the multiple scales of energy injection from champagne flows and the photoionization of clumps and filaments leads to a flatter spectrum of fluctuations than would be expected from top-down turbulence driven at the largest scales. The traditional structure function approach to the observational study of velocity fluctuations is shown to be incapable of reliably determining the velocity power spectrum of our simulation. We find that a more promising approach is the Velocity Channel Analysis technique of Lazarian & Pogosyan (2000), which, despite being intrinsically limited by thermal broadening, can successfully recover the logarithmic slope of the velocity power spectrum to a precision of +/- 0.1 from high-resolution optical emission-line spectroscopy.
Place, publisher, year, edition, pages
2014. Vol. 445, no 2, 1797-1819 p.
hydrodynamics, turbulence, H II regions, ISM: kinematics and dynamics
Astronomy, Astrophysics and Cosmology
IdentifiersURN: urn:nbn:se:kth:diva-159027DOI: 10.1093/mnras/stu1862ISI: 000346959400061OAI: oai:DiVA.org:kth-159027DiVA: diva2:785704
QC 201502032015-02-032015-01-202015-02-03Bibliographically approved