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The VMC survey - XXXI: The spatially resolved star formation history of the main body of the Small Magellanic Cloud
被引:85
作者:
Rubele, Stefano
[1
,2
]
Pastorelli, Giada
[1
]
Girardi, Leo
[2
]
Cioni, Maria-Rosa L.
[3
]
Zaggia, Simone
[2
]
Marigo, Paola
[1
]
Bekki, Kenji
[4
]
Bressan, Alessandro
[5
]
Clementini, Gisella
[6
]
de Grijs, Richard
[7
,8
,9
]
Emerson, Jim
[10
]
Groenewegen, Martin A. T.
[11
]
Ivanov, Valentin D.
[12
,13
]
Muraveva, Tatiana
[6
]
Nanni, Ambra
[1
]
Oliveira, Joana M.
[14
]
Ripepi, Vincenzo
[15
]
Sun, Ning-Chen
[8
,16
]
van Loon, Jacco Th.
[14
]
机构:
[1] Univ Padua, Dipartimento Fis & Astron, Vicolo Osservatorio 2, I-35122 Padua, Italy
[2] INAF, Osservatorio Astron Padova, Vicolo Osservatorio 5, I-35122 Padua, Italy
[3] Leibniz Inst Astrophys Potsdam, Sternwarte 16, D-14482 Potsdam, Germany
[4] Univ Western Australia, CRAR, M468, 35 Stirling Hwy, Crawley, WA 6009, Australia
[5] SISSA, Via Bonomea 265, I-34136 Trieste, Italy
[6] Osservatorio Astrofis & Sci Spazio Bologna, INAF, Via Piero Gobetti 93-3, I-40129 Bologna, Italy
[7] Macquarie Univ, Dept Phys & Astron, Balaclava Rd, N Ryde, NSW 2109, Australia
[8] Peking Univ, Kavli Inst Astron & Astrophys, Yi He Yuan Lu 5, Beijing 100871, Peoples R China
[9] Int Space Sci Inst Beijing, 1 Nanertiao, Beijing 100190, Peoples R China
[10] Queen Mary Univ London, Sch Phys & Astron, Astron Unit, Mile End Rd, London E1 4NS, England
[11] Koninklijke Sterrenwacht Belgie, Ringlaan 3, B-1180 Brussels, Belgium
[12] European Southern Observ, Ave Alonso de Cordova 3107, Santiago, Chile
[13] European Southern Observ, Karl Schwarzschild Str 2, D-85748 Garching, Germany
[14] Keele Univ, Lennard Jones Labs, Keele ST5 5BG, Staffs, England
[15] Osserv Astron Capodimonte, INAF, Via Moiariello 16, I-80131 Naples, Italy
[16] Peking Univ, Dept Astron, Yi He Yuan Lu 5, Beijing 100871, Peoples R China
基金:
欧洲研究理事会;
中国国家自然科学基金;
关键词:
Hertzsprung-Russell and colour-magnitude diagrams;
galaxies: evolution;
Magellanic Clouds;
galaxies: stellar content;
DATA-FLOW SYSTEM;
STELLAR POPULATIONS;
ISOCHRONES;
BRIDGE;
SMC;
I;
EVOLUTION;
CEPHEIDS;
TRACKS;
WFCAM;
D O I:
10.1093/mnras/sty1279
中图分类号:
P1 [天文学];
学科分类号:
0704 ;
摘要:
We recover the spatially resolved star formation history across the entire main body and Wing of the Small Magellanic Cloud (SMC), using 14 deep tile images from the VISTA survey of the Magellanic Clouds (VMC) in the YJK(s) filters. The analysis is performed on 168 subregions of size 0.143 deg(2) covering a total contiguous area of 23.57 deg(2). We apply a colour-magnitude diagram (CMD) reconstruction method that returns the best-fitting star formation rate SFR(t), age-metallicity relation, distance and mean reddening, together with their confidence intervals, for each subregion. With respect to previous analyses, we use a far larger set of the VMC data, updated stellar models, and fit the two available CMDs (Y - K-s versus K-s and J - K-s versus K-s) independently. The results allow us to derive a more complete and more reliable picture of how the mean distances, extinction values, star formation rate, and metallicities vary across the SMC, and provide a better description of the populations that form its Bar and Wing. We conclude that the SMC has formed a total mass of (5.31 +/- 0.05) x 10(8) M-circle dot in stars over its lifetime. About two-thirds of this mass is expected to be still locked in stars and stellar remnants. 50 per cent of the mass was formed prior to an age of 6.3 Gyr, and 80 per cent was formed between 8 and 3.5 Gyr ago. We also illustrate the likely distribution of stellar ages and metallicities in different parts of the CMD, to aid the interpretation of data from future astrometric and spectroscopic surveys of the SMC.
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页码:5017 / 5036
页数:20
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