The Gaia-ESO Survey: Asymmetric expansion of the Lagoon Nebula cluster NGC 6530 from GES and Gaia DR2
Author
dc.contributor.author
Wright, Nicholas J.
Author
dc.contributor.author
Jeffries, R. D.
Author
dc.contributor.author
Jackson, R. J.
Author
dc.contributor.author
Bayo, A.
Author
dc.contributor.author
Bonito, R.
Author
dc.contributor.author
Damiani, F.
Author
dc.contributor.author
Kalari, V.
Author
dc.contributor.author
Lanzafame, A. C.
Author
dc.contributor.author
Pancino, E.
Author
dc.contributor.author
Parker, R. J.
Author
dc.contributor.author
Prisinzano, L.
Author
dc.contributor.author
Randich, S.
Author
dc.contributor.author
Vink, J. S.
Author
dc.contributor.author
Alfaro, E. J.
Author
dc.contributor.author
Bergemann, M.
Author
dc.contributor.author
Franciosini, E.
Author
dc.contributor.author
Gilmore, G.
Author
dc.contributor.author
Gonneau, A.
Author
dc.contributor.author
Hourihane,
Admission date
dc.date.accessioned
2019-10-30T15:28:57Z
Available date
dc.date.available
2019-10-30T15:28:57Z
Publication date
dc.date.issued
2019
Cita de ítem
dc.identifier.citation
Monthly Notices of the Royal Astronomical Society, Volumen 486, Issue 2, 2019, Pages 2477-2493
Identifier
dc.identifier.issn
13652966
Identifier
dc.identifier.issn
00358711
Identifier
dc.identifier.other
10.1093/mnras/stz870
Identifier
dc.identifier.uri
https://repositorio.uchile.cl/handle/2250/172427
Abstract
dc.description.abstract
The combination of precise radial velocities from multi-object spectroscopy and highly accurate proper motions from Gaia DR2 opens up the possibility for detailed 3D kinematic studies of young star-forming regions and clusters. Here, we perform such an analysis by combining Gaia-ESO Survey spectroscopy with Gaia astrometry for ∼900 members of the Lagoon Nebula cluster, NGC 6530. We measure the 3D velocity dispersion of the region to be 5.35+0.39 -0.34 km s-1, which is large enough to suggest the region is gravitationally unbound. The velocity ellipsoid is anisotropic, implying that the region is not sufficiently dynamically evolved to achieve isotropy, though the central part of NGC 6530 does exhibit velocity isotropy that suggests sufficient mixing has occurred in this denser part. We find strong evidence that the stellar population is expanding, though this is preferentially occurring in the declination direction and there is very little evidence for expansion in the right ascension direction. This argues against a simple radial expansion pattern, as predicted by models of residual gas expulsion. We discuss these findings in the context of cluster formation, evolution, and disruption theories.