Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
The young stellar content of the giant H ii regions M8, G333.6 0.2, and NGC6357 with VLT/KMOS
Stockholm University, Faculty of Science, Department of Astronomy. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
Show others and affiliations
Number of Authors: 172020 (English)In: Astronomy and Astrophysics, ISSN 0004-6361, E-ISSN 1432-0746, Vol. 633, article id A155Article in journal (Refereed) Published
Abstract [en]

Context. The identification and characterisation of populations of young massive stars in (giant) HII regions provides important constraints on (i) the formation process of massive stars and their early feedback on the environment, and (ii) the initial conditions for population synthesis models predicting the evolution of ensembles of stars. Aims. We identify and characterise the stellar populations of the following young giant HII regions: M 8, G333.6-0.2, and NGC 6357. Methods. We have acquired H- and K-band spectra of around 200 stars using the K-band Multi Object Spectrograph on the ESO Very Large Telescope. The targets for M 8 and NGC 6357 were selected from the Massive Young Star-Forming Complex Study in Infrared and X-ray (MYStIX), which combines X-ray observations with near-infrared (NIR) and mid-infrared data. For G333.6-0.2, the sample selection is based on the NIR colours combined with X-ray data. We introduce an automatic spectral classification method in order to obtain temperatures and luminosities for the observed stars. We analysed the stellar populations using their photometric, astrometric, and spectroscopic properties and compared the position of the stars in the Hertzprung-Russell diagram with stellar evolution models to constrain their ages and mass ranges. Results. We confirm the presence of candidate ionising sources in the three regions and report new ones, including the first spectroscopically identified O stars in G333.6-0.2. In M 8 and NGC 6357, two populations are identified: (i) OB main-sequence stars (M> 5 M-circle dot) and (ii) pre-main sequence stars (M approximate to 0.5 - 5M(circle dot)). The ages of the clusters are similar to 1-3 Myr, < 3 Myr, and similar to 0.5-3 Myr for M 8, G333.6-0.2, and NGC 6357, respectively. We show that MYStIX selected targets have > 90% probability of being members of the HII region, whereas a selection based on NIR colours leads to a membership probability of only similar to 70%.

Place, publisher, year, edition, pages
2020. Vol. 633, article id A155
Keywords [en]
HII regions, stars, pre-main sequence, stars, formation, X-rays, stars, infrared: stars
National Category
Astronomy, Astrophysics and Cosmology
Identifiers
URN: urn:nbn:se:su:diva-179607DOI: 10.1051/0004-6361/201935941ISI: 000509543700001OAI: oai:DiVA.org:su-179607DiVA, id: diva2:1415399
Available from: 2020-03-18 Created: 2020-03-18 Last updated: 2020-03-18Bibliographically approved

Open Access in DiVA

No full text in DiVA

Other links

Publisher's full text

Search in DiVA

By author/editor
Bik, Adrianus
By organisation
Department of AstronomyThe Oskar Klein Centre for Cosmo Particle Physics (OKC)
In the same journal
Astronomy and Astrophysics
Astronomy, Astrophysics and Cosmology

Search outside of DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 1 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf