Fragmentation of vertically stratified gaseous layers: monolithic or coalescence-driven collapse

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985815%3A_____%2F17%3A00484223" target="_blank" >RIV/67985815:_____/17:00484223 - isvavai.cz</a>

Result on the web

<a href="http://dx.doi.org/10.1093/mnras/stw3354" target="_blank" >http://dx.doi.org/10.1093/mnras/stw3354</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1093/mnras/stw3354" target="_blank" >10.1093/mnras/stw3354</a>

Result language

angličtina

Original language name

Fragmentation of vertically stratified gaseous layers: monolithic or coalescence-driven collapse

Original language description

We investigate, using 3D hydrodynamic simulations, the fragmentation of pressure-confined, vertically stratified, self-gravitating gaseous layers. The confining pressure is either thermal pressure acting on both surfaces or thermal pressure acting on one surface and ram pressure on the other. In the linear regime of fragmentation, the dispersion relation we obtain agrees well with that derived by Elmegreen & Elmegreen, and consequently deviates from the dispersion relations based on the thin shell approximation or pressure assisted gravitational instability. In the non-linear regime, the relative importance of the confining pressure to the self-gravity is a crucial parameter controlling the qualitative course of fragmentation. When confinement of the layer is dominated by external pressure, self-gravitating condensations are delivered by a two-stage process: first the layer fragments into gravitationally bound but stable clumps, and then these clumps coalesce until they assemble enough mass to collapse. In contrast, when external pressure makes a small contribution to confinement of the layer, the layer fragments monolithically into gravitationally unstable clumps and there is no coalescence. This dichotomy persists whether the external pressure is thermal or ram. We apply these results to fragments forming in a shell swept up by an expanding H II region, and find that, unless the swept-up gas is quite hot or the surrounding medium has low density, the fragments have low mass (less than or similar to 3M(circle dot)), and therefore they are unlikely to spawn stars that are sufficiently massive to promote sequential self-propagating star formation.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

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OECD FORD branch

10308 - Astronomy (including astrophysics,space science)

Project

<a href="/en/project/GAP209%2F12%2F1795" target="_blank" >GAP209/12/1795: Star formation triggered by expanding shells</a><br>

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year

2017

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Monthly Notices of the Royal Astronomical Society

ISSN

0035-8711

e-ISSN

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Volume of the periodical

466

Issue of the periodical within the volume

4

Country of publishing house

GB - UNITED KINGDOM

Number of pages

19

Pages from-to

4423-4441

UT code for WoS article

000402849400048

EID of the result in the Scopus database

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