The spatial structure of young stellar clusters. I. Subclusters

Michael A. Kuhn, Eric D. Feigelson, Konstantin V. Getman, Adrian J. Baddeley, Patrick S. Broos, Alison Sills, Matthew R. Bate, Matthew S. Povich, Kevin L. Luhman, Heather A. Busk, Tim Naylor, Robert R. King

Research output: Contribution to journalArticle

67 Citations (Scopus)

Abstract

The clusters of young stars in massive star-forming regions show a wide range of sizes, morphologies, and numbers of stars. Their highly subclustered structures are revealed by the MYStIX project's sample of 31,754 young stars in nearby sites of star formation (regions at distances <3.6 kpc that contain at least one O-type star.) In 17 of the regions surveyed by MYStIX, we identify subclusters of young stars using finite mixture models - collections of isothermal ellipsoids that model individual subclusters. Maximum likelihood estimation is used to estimate the model parameters, and the Akaike Information Criterion is used to determine the number of subclusters. This procedure often successfully finds famous subclusters, such as the BN/KL complex behind the Orion Nebula Cluster and the KW-object complex in M 17. A catalog of 142 subclusters is presented, with 1-20 subclusters per region. The subcluster core radius distribution for this sample is peaked at 0.17 pc with a standard deviation of 0.43 dex, and subcluster core radius is negatively correlated with gas/dust absorption of the stars - a possible age effect. Based on the morphological arrangements of subclusters, we identify four classes of spatial structure: long chains of subclusters, clumpy structures, isolated clusters with a core-halo structure, and isolated clusters well fit by a single isothermal ellipsoid.

Original languageEnglish (US)
Article number107
JournalAstrophysical Journal
Volume787
Issue number2
DOIs
StatePublished - Jun 1 2014

Fingerprint

stars
ellipsoids
Akaike information criterion
Orion nebula
radii
dust
massive stars
catalogs
young
star formation
standard deviation
halos
gas
estimates
gases
parameter
project
effect
distribution

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this

Kuhn, Michael A. ; Feigelson, Eric D. ; Getman, Konstantin V. ; Baddeley, Adrian J. ; Broos, Patrick S. ; Sills, Alison ; Bate, Matthew R. ; Povich, Matthew S. ; Luhman, Kevin L. ; Busk, Heather A. ; Naylor, Tim ; King, Robert R. / The spatial structure of young stellar clusters. I. Subclusters. In: Astrophysical Journal. 2014 ; Vol. 787, No. 2.
@article{813ffe9cd3f0405ca3b34265374d295c,
title = "The spatial structure of young stellar clusters. I. Subclusters",
abstract = "The clusters of young stars in massive star-forming regions show a wide range of sizes, morphologies, and numbers of stars. Their highly subclustered structures are revealed by the MYStIX project's sample of 31,754 young stars in nearby sites of star formation (regions at distances <3.6 kpc that contain at least one O-type star.) In 17 of the regions surveyed by MYStIX, we identify subclusters of young stars using finite mixture models - collections of isothermal ellipsoids that model individual subclusters. Maximum likelihood estimation is used to estimate the model parameters, and the Akaike Information Criterion is used to determine the number of subclusters. This procedure often successfully finds famous subclusters, such as the BN/KL complex behind the Orion Nebula Cluster and the KW-object complex in M 17. A catalog of 142 subclusters is presented, with 1-20 subclusters per region. The subcluster core radius distribution for this sample is peaked at 0.17 pc with a standard deviation of 0.43 dex, and subcluster core radius is negatively correlated with gas/dust absorption of the stars - a possible age effect. Based on the morphological arrangements of subclusters, we identify four classes of spatial structure: long chains of subclusters, clumpy structures, isolated clusters with a core-halo structure, and isolated clusters well fit by a single isothermal ellipsoid.",
author = "Kuhn, {Michael A.} and Feigelson, {Eric D.} and Getman, {Konstantin V.} and Baddeley, {Adrian J.} and Broos, {Patrick S.} and Alison Sills and Bate, {Matthew R.} and Povich, {Matthew S.} and Luhman, {Kevin L.} and Busk, {Heather A.} and Tim Naylor and King, {Robert R.}",
year = "2014",
month = "6",
day = "1",
doi = "10.1088/0004-637X/787/2/107",
language = "English (US)",
volume = "787",
journal = "Astrophysical Journal",
issn = "0004-637X",
publisher = "IOP Publishing Ltd.",
number = "2",

}

Kuhn, MA, Feigelson, ED, Getman, KV, Baddeley, AJ, Broos, PS, Sills, A, Bate, MR, Povich, MS, Luhman, KL, Busk, HA, Naylor, T & King, RR 2014, 'The spatial structure of young stellar clusters. I. Subclusters', Astrophysical Journal, vol. 787, no. 2, 107. https://doi.org/10.1088/0004-637X/787/2/107

The spatial structure of young stellar clusters. I. Subclusters. / Kuhn, Michael A.; Feigelson, Eric D.; Getman, Konstantin V.; Baddeley, Adrian J.; Broos, Patrick S.; Sills, Alison; Bate, Matthew R.; Povich, Matthew S.; Luhman, Kevin L.; Busk, Heather A.; Naylor, Tim; King, Robert R.

In: Astrophysical Journal, Vol. 787, No. 2, 107, 01.06.2014.

Research output: Contribution to journalArticle

TY - JOUR

T1 - The spatial structure of young stellar clusters. I. Subclusters

AU - Kuhn, Michael A.

AU - Feigelson, Eric D.

AU - Getman, Konstantin V.

AU - Baddeley, Adrian J.

AU - Broos, Patrick S.

AU - Sills, Alison

AU - Bate, Matthew R.

AU - Povich, Matthew S.

AU - Luhman, Kevin L.

AU - Busk, Heather A.

AU - Naylor, Tim

AU - King, Robert R.

PY - 2014/6/1

Y1 - 2014/6/1

N2 - The clusters of young stars in massive star-forming regions show a wide range of sizes, morphologies, and numbers of stars. Their highly subclustered structures are revealed by the MYStIX project's sample of 31,754 young stars in nearby sites of star formation (regions at distances <3.6 kpc that contain at least one O-type star.) In 17 of the regions surveyed by MYStIX, we identify subclusters of young stars using finite mixture models - collections of isothermal ellipsoids that model individual subclusters. Maximum likelihood estimation is used to estimate the model parameters, and the Akaike Information Criterion is used to determine the number of subclusters. This procedure often successfully finds famous subclusters, such as the BN/KL complex behind the Orion Nebula Cluster and the KW-object complex in M 17. A catalog of 142 subclusters is presented, with 1-20 subclusters per region. The subcluster core radius distribution for this sample is peaked at 0.17 pc with a standard deviation of 0.43 dex, and subcluster core radius is negatively correlated with gas/dust absorption of the stars - a possible age effect. Based on the morphological arrangements of subclusters, we identify four classes of spatial structure: long chains of subclusters, clumpy structures, isolated clusters with a core-halo structure, and isolated clusters well fit by a single isothermal ellipsoid.

AB - The clusters of young stars in massive star-forming regions show a wide range of sizes, morphologies, and numbers of stars. Their highly subclustered structures are revealed by the MYStIX project's sample of 31,754 young stars in nearby sites of star formation (regions at distances <3.6 kpc that contain at least one O-type star.) In 17 of the regions surveyed by MYStIX, we identify subclusters of young stars using finite mixture models - collections of isothermal ellipsoids that model individual subclusters. Maximum likelihood estimation is used to estimate the model parameters, and the Akaike Information Criterion is used to determine the number of subclusters. This procedure often successfully finds famous subclusters, such as the BN/KL complex behind the Orion Nebula Cluster and the KW-object complex in M 17. A catalog of 142 subclusters is presented, with 1-20 subclusters per region. The subcluster core radius distribution for this sample is peaked at 0.17 pc with a standard deviation of 0.43 dex, and subcluster core radius is negatively correlated with gas/dust absorption of the stars - a possible age effect. Based on the morphological arrangements of subclusters, we identify four classes of spatial structure: long chains of subclusters, clumpy structures, isolated clusters with a core-halo structure, and isolated clusters well fit by a single isothermal ellipsoid.

UR - http://www.scopus.com/inward/record.url?scp=84901044832&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84901044832&partnerID=8YFLogxK

U2 - 10.1088/0004-637X/787/2/107

DO - 10.1088/0004-637X/787/2/107

M3 - Article

AN - SCOPUS:84901044832

VL - 787

JO - Astrophysical Journal

JF - Astrophysical Journal

SN - 0004-637X

IS - 2

M1 - 107

ER -