C.D.S. - SIMBAD4 rel 1.7 - 2020.02.28CET12:08:51

2019A&A...626A..79P - Astronomy and Astrophysics, volume 626A, 79-79 (2019/6-1)

Do star clusters form in a completely mass-segregated way?


Abstract (from CDS):

Context. ALMA observations of the Serpens South star-forming region suggest that stellar protoclusters may be completely mass segregated at birth. Independent observations also suggest that embedded clusters form segregated by mass.
Aims. As the primordial mass segregation seems to be lost over time, we aim to study on which timescale an initially perfectly mass-segregated star cluster becomes indistinguishable from an initially not mass-segregated cluster. As an example, the Orion Nebula Cluster (ONC) is also discussed.
Methods. We used N-body simulations of star clusters with various masses and two different degrees of primordial mass segregation. We analysed their energy redistribution through two-body relaxation to quantify the time when the models agree in terms of mass segregation, which sets in only dynamically in the models that are primordially not mass segregated. A comprehensive cross-matched catalogue combining optical, infrared, and X-ray surveys of ONC members was also compiled and made available.
Results. The models evolve to a similar radial distribution of high-mass stars after the core collapse (about half a median two-body relaxation time, trh) and become observationally indistinguishable from the point of view of mass segregation at time τv~=3.3trh. In the case of the ONC, using the distribution of high-mass stars, we may not rule out either evolutionary scenario (regardless of whether they are initially mass segregated). When we account for extinction and elongation of the ONC, as reported elsewhere, an initially perfectly mass-segregated state seems to be more consistent with the observed cluster.

Abstract Copyright: © ESO 2019

Journal keyword(s): methods: numerical - methods: data analysis - galaxies: star clusters: individual: ONC - stars: formation

VizieR on-line data: <Available at CDS (J/A+A/626/A79): table3.dat>

Status in Simbad:  could be processed

CDS comments: [H97b] 3000, [H97b] 5999 not identified.

Simbad objects: 8

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Number of rows : 8

N Identifier Otype ICRS (J2000)
ICRS (J2000)
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2020
1 NAME Taurus Dark Cloud SFR 04 41.0 +25 52           ~ 3380 0
2 NAME Orion Nebula Cluster OpC 05 35.0 -05 29           ~ 1932 1
3 M 42 HII 05 35 17.3 -05 23 28           ~ 3687 0
4 NAME Ori A MoC 05 38 -07.1           ~ 2639 0
5 NAME ORI MOL CLOUD MoC 05 56 -01.8           ~ 831 1
6 GCl 17 GlC 11 29 16.80 +28 58 25.0   14.4       ~ 309 1
7 NAME Serpens Cloud SFR 18 29 49 +01 14.8           ~ 898 2
8 NAME Serpens South Cluster Cl* 18 30 03.00 -02 01 58.2           ~ 85 0

    Equat.    Gal    SGal    Ecl

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