SCHNEIDER, N.; BONTEMPS, Sylvain; GIRICHIDIS, P.; RAYNER, T.; MOTTE, F.; ANDRÉ, P.; RUSSEIL, D.; ABERGEL, A.; ANDERSON, L.; ARZOUMANIAN, D.; BENEDETTINI, M.; CSENGERI, T.,; DIDELON, P.; FRANCESCO, J. D.; GRIFFIN, M.,; HILL, T.; KLESSEN, R. S.; OSSENKOPF, V.; PEZZUTO, S.; RIVERA-INGRAHAM, A.,; SPINOGLIO, L.; TREMBLIN, Pascal; ZAVAGNO, Annie

doi:10.1093/mnrasl/slv101

Métadonnées

Afficher la notice complète

Licence d’utilisation du document

SCHNEIDER, N.
FORMATION STELLAIRE 2015
Universität zu Köln = University of Cologne

BONTEMPS, Sylvain
FORMATION STELLAIRE 2015

GIRICHIDIS, P.
Max-Planck-Institut für Astrophysik [MPA]

Langue

Article de revue

Ce document a été publié dans

Monthly Notices of the Royal Astronomical Society. 2015, vol. 453, p. 41-45

Oxford University Press (OUP): Policy P - Oxford Open Option A

Résumé en anglais

We report the novel detection of complex high-column density tails in the probability distribution functions (PDFs) for three high-mass star-forming regions (CepOB3, MonR2, NGC6334), obtained from dust emission observed with Herschel. The low column density range can be fit with a lognormal distribution. A first power-law tail starts above an extinction (A$_v$) of ~6-14. It has a slope of $\alpha$ = 1.3$-$2 for the $\rho$ $\alpha$ $r^{-\alpha}$ profile for an equivalent density distribution (spherical or cylindrical geometry), and is thus consistent with free-fall gravitational collapse. Above A$_v$~40, 60, and 140, we detect an excess that can be fitted by a flatter power law tail with $\alpha$ > 2. It correlates with the central regions of the cloud (ridges/hubs) of size ~1 pc and densities above 10$^4$ cm$^{-3}$. This excess may be caused by physical processes that slow down collapse and reduce the flow of mass towards higher densities. Possible are: 1. rotation, which introduces an angular momentum barrier, 2. increasing optical depth and weaker cooling, 3. magnetic fields, 4. geometrical effects, and 5. protostellar feedback. The excess/second power-law tail is closely linked to high-mass star-formation though it does not imply a universal column density threshold for the formation of (high-mass) stars.< Réduire

Mots clés en anglais

ISM: clouds

dust extinction

DOI

http://dx.doi.org/10.1093/mnrasl/slv101

Projet Européen

Toward a Complete View of Star Formation: The Origin of Molecular Clouds, Prestellar Cores, and Star Clusters

Project ANR

Vers une vision unifiée de la formation stellaire dans les galaxies : Origine de la structure filamentaire du milieu interstellaire, des cœurs pré-stellaires et des amas protostellaires vus avec Herschel

Origine

Importé de hal

Unités de recherche

Laboratoire d'Astrophysique de Bordeaux (LAB) - UMR 5804