The massive star initial mass function of the Arches cluster

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dc.contributor.authorEspinoza, P.
dc.contributor.authorSelman, F. J.
dc.contributor.authorMelnick, J.
dc.date.accessioned2025-01-21T00:08:38Z
dc.date.available2025-01-21T00:08:38Z
dc.date.issued2009
dc.description.abstractThe massive Arches cluster near the Galactic center should be an ideal laboratory for investigating massive star formation under extreme conditions. But it comes at a high price: the cluster is hidden behind several tens of magnitudes of visual extinction. Severe crowding requires space or AO-assisted instruments to resolve the stellar populations, and even with the best instruments interpreting the data is far from direct. Several investigations using NICMOS and the most advanced AO imagers on the ground revealed an overall top-heavy IMF for the cluster, with a very flat IMF near the center. There are several effects, however, that could potentially bias these results, in particular the strong differential extinction and the problem of transforming the observations into a standard photometric system in the presence of strong reddening. We present new observations obtained with the NAOS-Conica (NACO) AO-imager on the VLT. The problem of photometric transformation is avoided by working in the natural photometric system of NACO, and we use a Bayesian approach to determine masses and reddenings from the broad-band IR colors. A global value of Gamma = -1.1 +/- 0.2 for the high-mass end (M > 10 M-circle dot) of the IMF is obtained, and we conclude that a power law of Salpeter slope cannot be discarded for the Arches cluster. The flattening of the IMF towards the center is confirmed, but is less severe than previously thought. We find Gamma = -0.88 +/- 0.20, which is incompatible with previous determinations. Within 0.4 pc we derive a total mass of similar to 2.0(+/- 0.6) x 10(4) M-circle dot for the cluster and a central mass density rho = 2(+/- 0.4) x 10(5) M-circle dot pc(-3) that confirms Arches as the densest known young massive cluster in the Milky Way.
dc.fuente.origenWOS
dc.identifier.doi10.1051/0004-6361/20078597
dc.identifier.eissn1432-0746
dc.identifier.issn0004-6361
dc.identifier.urihttps://doi.org/10.1051/0004-6361/20078597
dc.identifier.urihttps://repositorio.uc.cl/handle/11534/95677
dc.identifier.wosidWOS:000268125300017
dc.issue.numero2
dc.language.isoen
dc.pagina.final583
dc.pagina.inicio563
dc.revistaAstronomy & astrophysics
dc.rightsacceso restringido
dc.subjectGalaxy: open clusters and associations: individual: Arches
dc.subjectstars: early-type
dc.subjectinstrumentation: adaptive optics
dc.subjectISM: dust, extinction
dc.subjectstars: luminosity function, mass function
dc.titleThe massive star initial mass function of the Arches cluster
dc.typeartículo
dc.volumen501
sipa.indexWOS
sipa.trazabilidadWOS;2025-01-12
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