HIT REGIONS IN HYDROSTATIC BALANCE BETWEEN GAS PRESSURE, RADIATION PRESSURE AND GRAVITY
2015 (English)In: Revista mexicana de astronomía y astrofísica, ISSN 0185-1101, Vol. 51, no 1, 27-34 p.Article in journal (Refereed) Published
We study the solutions of a modified version of the isothermal Lane-Emden equation, which incorporates the effect of the (owtwards directed) radiation pressure resulting from photoionizations. These solutions are relevant for HIT regions around a cluster with over approximate to 500 O stars, which can photoionize gas out to approximate to 200 root 10 cm(-3)/n(0) pc (where n(0) is the central gas density), where the effects of the self-gravity and the radiation pressure become important. We find that the solutions have a transition from a "gravity dominated" regime (in which the solutions converge at large radii to the non-singular, isothermal sphere solution) to a "radiation pressure dominated" regime (in which the density diverges at a finite radius) for central HIT region densities above n(crit) = 100 cm(-3). We argue that the high central density, radiation pressure dominated solutions will not occur in most astrophysically relevant situations, because of the absence of a possible confining environment with a high enough pressure.
Place, publisher, year, edition, pages
2015. Vol. 51, no 1, 27-34 p.
hydrodynamics, ISM: evolution, ISM: kinematics and dynamics, ISM: HIT regions, stars: formation
Astronomy, Astrophysics and Cosmology
IdentifiersURN: urn:nbn:se:kth:diva-166502ISI: 000352521100003OAI: oai:DiVA.org:kth-166502DiVA: diva2:811899
FunderSwedish Research Council
QC 201505132015-05-132015-05-112015-05-13Bibliographically approved