A young cluster with an extended main-sequence turnoff: confirmation of a prediction of the stellar rotation scenario

被引：46

作者：

Bastian, N. ^{[1
]}

Niederhofer, F. ^{[2
,3
,4
]}

Kozhurina-Platais, V. ^{[4
]}

Salaris, M. ^{[1
]}

Larsen, S. ^{[5
]}

Cabrera-Ziri, I. ^{[1
,6
]}

Cordero, M. ^{[7
]}

Ekstrom, S. ^{[8
]}

Geisler, D. ^{[9
]}

Georgy, C. ^{[8
]}

Hilker, M. ^{[6
]}

Kacharov, N. ^{[10
]}

Li, C. ^{[11
]}

Mackey, D. ^{[12
]}

Mucciarelli, A. ^{[13
]}

Platais, I. ^{[14
]}

机构：

[1] Liverpool John Moores Univ, Astrophys Res Inst, 146 Brownlow Hill, Liverpool L3 5RF, Merseyside, England

[2] Excellence Cluster Origin & Struct Universe, Boltzmannstr 2, D-85748 Garching, Germany

[3] Univ Sternwarte Munchen, Scheinerstr 1, D-81679 Munich, Germany

[4] Space Telescope Sci Inst, 3700 San Martin Dr, Baltimore, MD 21218 USA

[5] Radboud Univ Nijmegen, Dept Astrophys, IMAPP, POB 9010, NL-6500 GL Nijmegen, Netherlands

[6] European Southern Observ, Karl Schwarzschild Str 2, D-85748 Garching, Germany

[7] Heidelberg Univ, Zentrum Astron, Astron Rechen Inst, Monchhofstr 12-14, D-69120 Heidelberg, Germany

[8] Univ Geneva, Geneva Observ, Maillettes 51, CH-1290 Sauverny, Switzerland

[9] Univ Concepcion, Dept Astron, Casilla 160-C, Concepcion, Chile

[10] Max Planck Inst Astron, Konigstuhl 17, D-69117 Heidelberg, Germany

[11] Macquarie Univ, Dept Phys & Astron, Sydney, NSW 2109, Australia

[12] Australian Natl Univ, Res Sch Astron & Astrophys, Canberra, ACT 2611, Australia

[13] Univ Bologna, Dept Phys & Astron, Viale Berti Pichat 6-2, I-40127 Bologna, Italy

[14] Johns Hopkins Univ, Dept Phys & Astron, 3400 North Charles St, Baltimore, MD 21218 USA

来源：

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY | 2016年 / 460卷 / 01期

基金：

欧洲研究理事会;

关键词：

galaxies: star clusters: individual: NGC 1850; STAR-FORMATION HISTORY; MAGELLANIC CLOUD CLUSTERS; SUB-GIANT BRANCH; M-CIRCLE-DOT; MASSIVE CLUSTERS; AGE SPREADS; POPULATION SYNTHESIS; EVOLUTION DATABASE; RED CLUMP; I; MODELS;

D O I：

10.1093/mnrasl/slw067

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

We present Hubble Space Telescope photometry of NGC 1850, a similar to 100 Myr, similar to 10(5) M-circle dot cluster in the Large Magellanic Cloud. The colour-magnitude diagram clearly shows the presence of an extended main-sequence turnoff (eMSTO). The use of non-rotating stellar isochrones leads to an age spread of similar to 40 Myr. This is in good agreement with the age range expected when the effects of rotation in the main-sequence turnoff (MSTO) stars are wrongly interpreted in terms of age spread. We also do not find evidence for multiple, isolated episodes of star formation bursts within the cluster, in contradiction to scenarios that invoke actual age spreads to explain the eMSTO phenomenon. NGC 1850 therefore continues the trend of eMSTO clusters, where the inferred age spread is proportional to the age of the cluster. While our results confirm a key prediction of the scenario where stellar rotation causes the eMSTO feature, direct measurements of the rotational rate of MSTO stars is required to definitively confirm or refute whether stellar rotation is the origin of the eMSTO phenomenon or if it is due to an as yet undiscovered effect.

引用

页码：L20 / L24

页数：5

共 48 条

[1] NEW LIMITS ON AN INTERMEDIATE-MASS BLACK HOLE IN OMEGA CENTAURI. I. HUBBLE SPACE TELESCOPE PHOTOMETRY AND PROPER MOTIONS [J].