中国科学院机构知识库网格
Chinese Academy of Sciences Institutional Repositories Grid
热门
A new photometric model of the Galactic bar using red clump giants

文献类型:期刊论文

作者Cao, Liang1; Mao, Shude1,2; Nataf, David3,4; Rattenbury, Nicholas J.2; Gould, Andrew4
刊名MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
出版日期2013-09-01
卷号434期号:1页码:595-605
关键词Galaxy: bulge Galaxy: centre Galaxy: stellar content Galaxy: structure
英文摘要We present a study of the luminosity density distribution of the Galactic bar using number counts of red clump giants from the Optical Gravitational Lensing Experiment (OGLE) III survey. The data were recently published by Nataf et al. for 9019 fields towards the bulge and have 2.94 x 10(6) RC stars over a viewing area of 90.25 deg(2). The data include the number counts, mean distance modulus (mu), dispersion in mu and full error matrix, from which we fit the data with several triaxial parametric models. We use the Markov Chain Monte Carlo method to explore the parameter space and find that the best-fitting model is the E-3 model, with the distance to the GC 8.13 kpc, the ratio of semimajor and semiminor bar axis scalelengths in the Galactic plane x(0), y(0) and vertical bar scalelength z(0) x(0): y(0): z(0) approximate to 1.00: 0.43: 0.40 (close to being prolate). The scalelength of the stellar density profile along the bar's major axis is similar to 0.67 kpc and has an angle of 29 degrees.4, slightly larger than the value obtained from a similar study based on OGLE-II data. The number of estimated RC stars within the field of view is 2.78 x 10(6), which is systematically lower than the observed value. We subtract the smooth parametric model from the observed counts and find that the residuals are consistent with the presence of an X-shaped structure in the Galactic Centre, the excess to the estimated mass content is similar to 5.8 per cent. We estimate that the total mass of the bar is similar to 1.8 x 10(10) M-circle dot. Our results can be used as a key ingredient to construct new density models of the Milky Way and will have implications on the predictions of the optical depth to gravitational microlensing and the patterns of hydrodynamical gas flow in the Milky Way.
收录类别SCI
语种英语
WOS记录号WOS:000323636800041
源URL[http://ir.bao.ac.cn/handle/114a11/5811]  
专题国家天文台_星系宇宙学研究部
作者单位1.Chinese Acad Sci, Natl Astron Observ, Beijing 100012, Peoples R China
2.Univ Manchester, Jodrell Bank, Ctr Astrophys, Manchester M13 9PL, Lancs, England
3.Australian Natl Univ, Res Sch Astron & Astrophys, Canberra, ACT 2611, Australia
4.Ohio State Univ, Dept Astron, Columbus, OH 43210 USA
推荐引用方式
GB/T 7714
Cao, Liang,Mao, Shude,Nataf, David,et al. A new photometric model of the Galactic bar using red clump giants[J]. MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY,2013,434(1):595-605.
APA Cao, Liang,Mao, Shude,Nataf, David,Rattenbury, Nicholas J.,&Gould, Andrew.(2013).A new photometric model of the Galactic bar using red clump giants.MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY,434(1),595-605.
MLA Cao, Liang,et al."A new photometric model of the Galactic bar using red clump giants".MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 434.1(2013):595-605.

入库方式: OAI收割

来源:国家天文台

浏览0
下载0
收藏0
其他版本

除非特别说明,本系统中所有内容都受版权保护,并保留所有权利。