Kinematics in Young Star Clusters and Associations with Gaia DR2

Michael A. Kuhn, Lynne A. Hillenbrand, Alison Sills, Eric D. Feigelson, Konstantin V. Getman

Research output: Contribution to journalArticle

20 Citations (Scopus)

Abstract

The Gaia mission has opened a new window into the internal kinematics of young star clusters at the sub-km s-1 level, with implications for our understanding of how star clusters form and evolve. We use a sample of 28 clusters and associations with ages from ∼1-5 Myr, where lists of members are available from previous X-ray, optical, and infrared studies. Proper motions from Gaia DR2 reveal that at least 75% of these systems are expanding; however, rotation is only detected in one system. Typical expansion velocities are on the order of ∼0.5 km s-1, and in several systems, there is a positive radial gradient in expansion velocity. Systems that are still embedded in molecular clouds are less likely to be expanding than those that are partially or fully revealed. One-dimensional velocity dispersions, which range from to 3 km s-1, imply that most of the stellar systems in our sample are supervirial and that some are unbound. In star-forming regions that contain multiple clusters or subclusters, we find no evidence that these groups are coalescing, implying that hierarchical cluster assembly, if it occurs, must happen rapidly during the embedded stage.

Original languageEnglish (US)
Article number32
JournalAstrophysical Journal
Volume870
Issue number1
DOIs
StatePublished - Jan 1 2019

Fingerprint

star clusters
kinematics
stellar systems
expansion
proper motion
molecular clouds
lists
coalescing
assembly
stars
gradients
young
x rays

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this

Kuhn, Michael A. ; Hillenbrand, Lynne A. ; Sills, Alison ; Feigelson, Eric D. ; Getman, Konstantin V. / Kinematics in Young Star Clusters and Associations with Gaia DR2. In: Astrophysical Journal. 2019 ; Vol. 870, No. 1.
@article{12eb8a548f5d4df0a97680e769983c54,
title = "Kinematics in Young Star Clusters and Associations with Gaia DR2",
abstract = "The Gaia mission has opened a new window into the internal kinematics of young star clusters at the sub-km s-1 level, with implications for our understanding of how star clusters form and evolve. We use a sample of 28 clusters and associations with ages from ∼1-5 Myr, where lists of members are available from previous X-ray, optical, and infrared studies. Proper motions from Gaia DR2 reveal that at least 75{\%} of these systems are expanding; however, rotation is only detected in one system. Typical expansion velocities are on the order of ∼0.5 km s-1, and in several systems, there is a positive radial gradient in expansion velocity. Systems that are still embedded in molecular clouds are less likely to be expanding than those that are partially or fully revealed. One-dimensional velocity dispersions, which range from to 3 km s-1, imply that most of the stellar systems in our sample are supervirial and that some are unbound. In star-forming regions that contain multiple clusters or subclusters, we find no evidence that these groups are coalescing, implying that hierarchical cluster assembly, if it occurs, must happen rapidly during the embedded stage.",
author = "Kuhn, {Michael A.} and Hillenbrand, {Lynne A.} and Alison Sills and Feigelson, {Eric D.} and Getman, {Konstantin V.}",
year = "2019",
month = "1",
day = "1",
doi = "10.3847/1538-4357/aaef8c",
language = "English (US)",
volume = "870",
journal = "Astrophysical Journal",
issn = "0004-637X",
publisher = "IOP Publishing Ltd.",
number = "1",

}

Kinematics in Young Star Clusters and Associations with Gaia DR2. / Kuhn, Michael A.; Hillenbrand, Lynne A.; Sills, Alison; Feigelson, Eric D.; Getman, Konstantin V.

In: Astrophysical Journal, Vol. 870, No. 1, 32, 01.01.2019.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Kinematics in Young Star Clusters and Associations with Gaia DR2

AU - Kuhn, Michael A.

AU - Hillenbrand, Lynne A.

AU - Sills, Alison

AU - Feigelson, Eric D.

AU - Getman, Konstantin V.

PY - 2019/1/1

Y1 - 2019/1/1

N2 - The Gaia mission has opened a new window into the internal kinematics of young star clusters at the sub-km s-1 level, with implications for our understanding of how star clusters form and evolve. We use a sample of 28 clusters and associations with ages from ∼1-5 Myr, where lists of members are available from previous X-ray, optical, and infrared studies. Proper motions from Gaia DR2 reveal that at least 75% of these systems are expanding; however, rotation is only detected in one system. Typical expansion velocities are on the order of ∼0.5 km s-1, and in several systems, there is a positive radial gradient in expansion velocity. Systems that are still embedded in molecular clouds are less likely to be expanding than those that are partially or fully revealed. One-dimensional velocity dispersions, which range from to 3 km s-1, imply that most of the stellar systems in our sample are supervirial and that some are unbound. In star-forming regions that contain multiple clusters or subclusters, we find no evidence that these groups are coalescing, implying that hierarchical cluster assembly, if it occurs, must happen rapidly during the embedded stage.

AB - The Gaia mission has opened a new window into the internal kinematics of young star clusters at the sub-km s-1 level, with implications for our understanding of how star clusters form and evolve. We use a sample of 28 clusters and associations with ages from ∼1-5 Myr, where lists of members are available from previous X-ray, optical, and infrared studies. Proper motions from Gaia DR2 reveal that at least 75% of these systems are expanding; however, rotation is only detected in one system. Typical expansion velocities are on the order of ∼0.5 km s-1, and in several systems, there is a positive radial gradient in expansion velocity. Systems that are still embedded in molecular clouds are less likely to be expanding than those that are partially or fully revealed. One-dimensional velocity dispersions, which range from to 3 km s-1, imply that most of the stellar systems in our sample are supervirial and that some are unbound. In star-forming regions that contain multiple clusters or subclusters, we find no evidence that these groups are coalescing, implying that hierarchical cluster assembly, if it occurs, must happen rapidly during the embedded stage.

UR - http://www.scopus.com/inward/record.url?scp=85059842342&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85059842342&partnerID=8YFLogxK

U2 - 10.3847/1538-4357/aaef8c

DO - 10.3847/1538-4357/aaef8c

M3 - Article

AN - SCOPUS:85059842342

VL - 870

JO - Astrophysical Journal

JF - Astrophysical Journal

SN - 0004-637X

IS - 1

M1 - 32

ER -