The VMC survey - XXXIX. Mapping metallicity trends in the Small Magellanic Cloud using near-infrared passbands

被引：18

作者：

Choudhury, Samyaday ^{[1
,2
]}

de Grijs, Richard ^{[1
,2
,3
]}

Rubele, Stefano ^{[4
,5
]}

Bekki, Kenji ^{[6
]}

Cioni, Maria-Rosa L. ^{[7
]}

Ivanov, Valentin D. ^{[8
]}

van Loon, Jacco Th ^{[9
]}

Niederhofer, Florian ^{[7
]}

Oliveira, Joana M. ^{[9
]}

Ripepi, Vincenzo ^{[10
]}

机构：

[1] Macquarie Univ, Dept Phys & Astron, Balaclava Rd, Sydney, NSW 2109, Australia

[2] Macquarie Univ, Res Ctr Astron Astrophys & Astrophoton, Balaclava Rd, Sydney, NSW 2109, Australia

[3] Int Space Sci Inst Beijing, 1 Nanertiao, Beijing 100190, Peoples R China

[4] Univ Padua, Dipartimento Fis & Astron, Vicolo Osservatorio 2, I-35122 Padua, Italy

[5] INAF, Osservatorio Astron Padova, Vicolo Osservatorio 5, I-35122 Padua, Italy

[6] Univ Western Australia, ICRAR, M468,35 Stirling Hwy, Crawley, WA 6009, Australia

[7] Leibniz Inst Astrophys Potsdam AIP, Sternwarte 16, D-14482 Potsdam, Germany

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

[9] Keele Univ, Lennard Jones Labs, Keele ST5 5BG, Staffs, England

[10] INAF Osservatorio Astron Capodimonte, Via Moiariello 16, I-80131 Naples, Italy

来源：

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY | 2020年 / 497卷 / 03期

基金：

欧洲研究理事会;

关键词：

stars: abundances; Hertzsprung-Russell and colour-magnitude diagrams; galaxies: abundances; galaxies: irregular; Local Group; Magellanic Clouds; II TRIPLET SPECTROSCOPY; CLUSTER GIANT BRANCHES; STAR-FORMATION HISTORY; RR LYRAE VARIABLES; STELLAR POPULATIONS; RED GIANTS; GLOBULAR-CLUSTERS; PROPER MOTION; ABUNDANCES; SYSTEM;

D O I：

10.1093/mnras/staa2140

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

We have derived high-spatial-resolution metallicity maps covering similar to 42 deg(2) across the Small Magellanic Cloud (SMC) in an attempt to understand its metallicity distribution and gradients up to a radius of similar to 4 degrees. Using the near-infrared VISTA Survey of the Magellanic Clouds, our data cover a thrice larger area compared with previous studies. We identify red giant branch (RGB) stars in spatially distinct Y, (Y - K-s) colour-magnitude diagrams. In any of our selected subregions, the RGB slope is used as an indicator of the average metallicity, based on calibration to metallicity using spectroscopic data. The metallicity distribution across the SMC is unimodal and can be fitted by a Gaussian distribution with a peak at [Fe/H] = -0.97 dex (sigma[Fe/H] = 0.05 dex). We find evidence of a shallow gradient in metallicity (-0.031 +/- 0.005 dex deg(-1)) from the Galactic Centre to radii of 2 degrees-2 degrees.5, followed by a flat metallicity trend from similar to 3 degrees.5 to 4 degrees. We find that the SMC's metallicity gradient is radially asymmetric. It is flatter towards the east than to the west, hinting at mixing and/or distortion of the spatial metallicity distribution (within the inner 3 degrees), presumably caused by tidal interactions between the Magellanic Clouds.

引用

页码：3746 / 3760

页数：15

共 87 条

[1] The detection of an older population in the Magellanic Bridge [J].