Multiple stellar populations in the globular cluster ω Centauri as tracers of a merger event

Y. W. Lee, J. M. Joo, Y. J. Sohn, S. C. Rey, H. C. Lee, A. R. Walker

Research output: Contribution to journalArticle

219 Citations (Scopus)

Abstract

The discovery of the Sagittarius dwarf galaxy, which is being tidally disrupted by and merging with the Milky Way, supports the view that the halo of the Galaxy has been built up at least partially by the accretion of similar dwarf systems. The Sagittarius dwarf contains several distinct populations of stars, and includes M54 as its nucleus, which is the second most massive globular cluster associated with the Milky Way. The most massive globular cluster is ω Centauri, and here we report that ω Centauri also has several distinct stellar populations, as traced by red-giant-branch stars. The most metal-rich red-giant-branch stars are about 2 Gyr younger than the dominant metal-poor component, indicating that ω Centauri was enriched over this timescale. The presence of more than one epoch of star formation in a globular cluster is quite surprising, and suggests that ω Centauri was once part of a more massive system that merged with the Milky Way, as the Sagittarius dwarf galaxy is in the process of doing now. Mergers probably were much more frequent in the early history of the Galaxy and ω Centauri appears to be a relict of this era.

Original languageEnglish
Pages (from-to)55-57
Number of pages3
JournalNature
Volume402
Issue number6757
DOIs
Publication statusPublished - 1999 Nov 4

Fingerprint

Galaxies
Population
Metals
History

All Science Journal Classification (ASJC) codes

  • Medicine(all)
  • General

Cite this

Lee, Y. W. ; Joo, J. M. ; Sohn, Y. J. ; Rey, S. C. ; Lee, H. C. ; Walker, A. R. / Multiple stellar populations in the globular cluster ω Centauri as tracers of a merger event. In: Nature. 1999 ; Vol. 402, No. 6757. pp. 55-57.
@article{c143ab37dc1240d694c2523411836f79,
title = "Multiple stellar populations in the globular cluster ω Centauri as tracers of a merger event",
abstract = "The discovery of the Sagittarius dwarf galaxy, which is being tidally disrupted by and merging with the Milky Way, supports the view that the halo of the Galaxy has been built up at least partially by the accretion of similar dwarf systems. The Sagittarius dwarf contains several distinct populations of stars, and includes M54 as its nucleus, which is the second most massive globular cluster associated with the Milky Way. The most massive globular cluster is ω Centauri, and here we report that ω Centauri also has several distinct stellar populations, as traced by red-giant-branch stars. The most metal-rich red-giant-branch stars are about 2 Gyr younger than the dominant metal-poor component, indicating that ω Centauri was enriched over this timescale. The presence of more than one epoch of star formation in a globular cluster is quite surprising, and suggests that ω Centauri was once part of a more massive system that merged with the Milky Way, as the Sagittarius dwarf galaxy is in the process of doing now. Mergers probably were much more frequent in the early history of the Galaxy and ω Centauri appears to be a relict of this era.",
author = "Lee, {Y. W.} and Joo, {J. M.} and Sohn, {Y. J.} and Rey, {S. C.} and Lee, {H. C.} and Walker, {A. R.}",
year = "1999",
month = "11",
day = "4",
doi = "10.1038/46985",
language = "English",
volume = "402",
pages = "55--57",
journal = "Nature",
issn = "0028-0836",
publisher = "Nature Publishing Group",
number = "6757",

}

Multiple stellar populations in the globular cluster ω Centauri as tracers of a merger event. / Lee, Y. W.; Joo, J. M.; Sohn, Y. J.; Rey, S. C.; Lee, H. C.; Walker, A. R.

In: Nature, Vol. 402, No. 6757, 04.11.1999, p. 55-57.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Multiple stellar populations in the globular cluster ω Centauri as tracers of a merger event

AU - Lee, Y. W.

AU - Joo, J. M.

AU - Sohn, Y. J.

AU - Rey, S. C.

AU - Lee, H. C.

AU - Walker, A. R.

PY - 1999/11/4

Y1 - 1999/11/4

N2 - The discovery of the Sagittarius dwarf galaxy, which is being tidally disrupted by and merging with the Milky Way, supports the view that the halo of the Galaxy has been built up at least partially by the accretion of similar dwarf systems. The Sagittarius dwarf contains several distinct populations of stars, and includes M54 as its nucleus, which is the second most massive globular cluster associated with the Milky Way. The most massive globular cluster is ω Centauri, and here we report that ω Centauri also has several distinct stellar populations, as traced by red-giant-branch stars. The most metal-rich red-giant-branch stars are about 2 Gyr younger than the dominant metal-poor component, indicating that ω Centauri was enriched over this timescale. The presence of more than one epoch of star formation in a globular cluster is quite surprising, and suggests that ω Centauri was once part of a more massive system that merged with the Milky Way, as the Sagittarius dwarf galaxy is in the process of doing now. Mergers probably were much more frequent in the early history of the Galaxy and ω Centauri appears to be a relict of this era.

AB - The discovery of the Sagittarius dwarf galaxy, which is being tidally disrupted by and merging with the Milky Way, supports the view that the halo of the Galaxy has been built up at least partially by the accretion of similar dwarf systems. The Sagittarius dwarf contains several distinct populations of stars, and includes M54 as its nucleus, which is the second most massive globular cluster associated with the Milky Way. The most massive globular cluster is ω Centauri, and here we report that ω Centauri also has several distinct stellar populations, as traced by red-giant-branch stars. The most metal-rich red-giant-branch stars are about 2 Gyr younger than the dominant metal-poor component, indicating that ω Centauri was enriched over this timescale. The presence of more than one epoch of star formation in a globular cluster is quite surprising, and suggests that ω Centauri was once part of a more massive system that merged with the Milky Way, as the Sagittarius dwarf galaxy is in the process of doing now. Mergers probably were much more frequent in the early history of the Galaxy and ω Centauri appears to be a relict of this era.

UR - http://www.scopus.com/inward/record.url?scp=0033523901&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0033523901&partnerID=8YFLogxK

U2 - 10.1038/46985

DO - 10.1038/46985

M3 - Article

VL - 402

SP - 55

EP - 57

JO - Nature

JF - Nature

SN - 0028-0836

IS - 6757

ER -