English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

In the present work we apply virial analysis to the model of self-gravitatingturbulent cloud ensembles introduced by Donkov \& Stefanov in two previouspapers, clarifying some aspects of turbulence and extending the model toaccount not only for supersonic flows but for trans- and subsonic ones as well.Make use of the Eulerian virial theorem at an arbitrary scale, far from thecloud core, we derive an equation for the density profile and solve it inapproximate way. The result confirms the solution $\varrho(\ell)=\ell^{-2}$found in the previous papers. This solution corresponds to three possibleconfigurations for the energy balance. For trans- or subsonic flows, we obtaina balance between the gravitational and thermal energy (Case 1) or between thegravitational, turbulent and thermal energies (Case 2) while for supersonicflows, the possible balance is between the gravitational and turbulent energy(Case 3). In Cases 1 and 2 the energy of the fluid element can be negative orzero end thus the solution is dynamically stable and shall be long lived. InCase 3 the energy of the fluid element is positive or zero, i.e., the solutionis unstable or at best marginally bound. At scales near the core, one cannotneglect the second derivative of the moment of inertia of the gas, whichprevents derivation of an analytic equation for the density profile. However,we obtain that gas near the core is not virialized and its state is marginallybound since the energy of the fluid element vanishes.

Density distribution function of a self-gravitating isothermal turbulent fluid in the context of molecular clouds ensembles -- III. Virial analysis