Change search
ReferencesLink to record
Permanent link

Direct link
Radiation-magnetohydrodynamic simulations of the photoionization of magnetized globules
Stockholm University, Faculty of Science, Department of Astronomy.
2009 (English)In: Monthly notices of the Royal Astronomical Society, ISSN 0035-8711, E-ISSN 1365-2966, Vol. 398, 157-175 p.Article in journal (Refereed) Published
Abstract [en]

We present the first three-dimensional radiation-magnetohydrodynamic simulations of the photoionization of a dense, magnetized molecular globule by an external source of ultraviolet radiation. We find that, for the case of a strong ionizing field, significant deviations from the non-magnetic evolution are seen when the initial magnetic field threading the globule has an associated magnetic pressure that is greater than 100 times the gas pressure. In such a strong-field case, the photoevaporating globule will adopt a flattened or `curled up' shape, depending on the initial field orientation, and magnetic confinement of the ionized photoevaporation flow can lead to recombination and subsequent fragmentation during advanced stages of the globule evolution. We find suggestive evidence that such magnetic effects may be important in the formation of bright, bar-like emission features in HII regions. We include simple but realistic fits to heating and cooling rates in the neutral and molecular gas in the vicinity of a high-mass star cluster, and show that the frequently used isothermal approximation can lead to an overestimate of the importance of gravitational instability in the radiatively imploded globule. For globules within 2 pc of a high-mass star cluster, we find that heating by stellar X-rays prevents the molecular gas from cooling below 50 K. Based in part on numerical simulations carried out using the Kan Balam supercomputer, operated by the Departamento de Supercómputo, Dirección General de Servicios de Cómputo Académico, Universidad Nacional Autónoma de México. E-mail:

Place, publisher, year, edition, pages
2009. Vol. 398, 157-175 p.
Keyword [en]
MHD, stars: formation, ISM: globules, HII regions
National Category
Astronomy, Astrophysics and Cosmology
Research subject
URN: urn:nbn:se:su:diva-31866DOI: 10.1111/j.1365-2966.2009.15153.xISI: 000269136800029OAI: diva2:278847
Available from: 2009-11-30 Created: 2009-11-30 Last updated: 2011-02-15Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full text
By organisation
Department of Astronomy
In the same journal
Monthly notices of the Royal Astronomical Society
Astronomy, Astrophysics and Cosmology

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 13 hits
ReferencesLink to record
Permanent link

Direct link