FIRST EVIDENCE OF FULLY SPATIALLY MIXED FIRST AND SECOND GENERATIONS IN GLOBULAR CLUSTERS: THE CASE OF NGC 6362

被引：64

作者：

Dalessandro, Emanuele ^{[1
]}

Massari, Davide ^{[1
]}

Bellazzini, Michele ^{[2
]}

Miocchi, Paolo ^{[1
]}

Mucciarelli, Alessio ^{[1
]}

Salaris, Maurizio ^{[3
]}

Cassisi, Santi ^{[4
]}

Ferraro, Francesco R. ^{[1
]}

Lanzoni, Barbara ^{[1
]}

机构：

[1] Univ Bologna, Dipartimento Fis & Astron, I-40127 Bologna, Italy

[2] INAF Osservatorio Astron Bologna, I-40127 Bologna, Italy

[3] Liverpool John Moores Univ, Astrophys Res Inst, Liverpool L3 5RF, Merseyside, England

[4] INAF Osservatorio Astron Collurania, I-64100 Teramo, Italy

来源：

ASTROPHYSICAL JOURNAL LETTERS | 2014年 / 791卷 / 01期

基金：

欧洲研究理事会;

关键词：

globular clusters: individual (NGC 6362); stars: Population II; MULTIPLE STELLAR POPULATIONS; DOUBLE SUBGIANT BRANCH; MASSIVE STAR-CLUSTERS; ACS SURVEY; MILKY-WAY; DYNAMICAL EVOLUTION; OMEGA-CENTAURI; PARAMETERS; ABUNDANCE; ORIGIN;

D O I：

10.1088/2041-8205/791/1/L4

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

We present the first evidence of multiple populations in the Galactic globular cluster NGC 6362. We used optical and near-UV Hubble Space Telescope and ground-based photometry, finding that both the sub-giant and red giant branches are split in two parallel sequences in all color-magnitude diagrams where the F336W filter (or U band) is used. This cluster is one of the least massive globulars (M-tot similar to 5 x 10(4) M-circle dot) where multiple populations have been detected so far. Even more interestingly and at odds with any previous finding, we observe that the two identified populations share the same radial distribution across the cluster extension. NGC 6362 is the first system where stars from different populations are found to be completely spatially mixed. Based on N-body and hydrodynamical simulations of multiple stellar generations, we argue that to reproduce these findings NGC 6362 should have lost up to 80% of its original mass.

引用

页数：5

共 46 条

[1] The orbits of 48 globular clusters in a Milky Way-like barred galaxy [J].