Testing three derivative methods of stellar population synthesis models

	Testing three derivative methods of stellar population synthesis models
	Zhang Y(张余)1,2,3 ; Han ZW(韩占文)1,3 ; Liu, JZ4 ; Zhang FH(张奉辉)1,3 ; Kang XY(康晓宇)1,2,3
刊名	MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
	2012-04
卷号	421 期号:2 页码:1678-1696
关键词	globular clusters: general galaxies: fundamental parameters galaxies: stellar content
ISSN号	0035-8711
通讯作者	Zhang, Y (reprint author), Chinese Acad Sci, Natl Astron Observ, Yunnan Observ, Kunming 650011, Peoples R China.
产权排序	第一完成单位
英文摘要	The number of methods used to study the properties of galaxies is increasing, and it is very important to test these methods. Galactic globular clusters (GCs) provide an excellent medium for such tests, because they can be considered as simple stellar populations. We present ages and metallicities for 40 Galactic GCs as determined from three publicly available techniques, namely the colour, Lick-index and spectrum-fitting methods, based on Bruzual & Charlot evolutionary population synthesis (EPS) models. By comparisons with the ages obtained from colour-magnitude diagrams (CMDs) and metallicities obtained from the spectra of stars, we are able to estimate the ability of these methods to determine GC parameters, which is essential. We find that: (i) for the metallicity, our derived metallicities agree with those derived from the spectra of stars - the Lick-index method is suitable for studying metallicity for stellar population systems in the range - 1.5 less than or similar to [Fe/H] less than or similar to -0.7 and the spectrum-fitting method is suitable for studying metallicity for stellar population systems in the range -2.3 less than or similar to [Fe/H] less than or similar to -1.5; (ii) for the age, these three methods have difficulties in age determination - our derived ages are smaller (by about 2.0 Gyr, on average) than the results of CMDs for all three methods. We use Vazdekis and Maraston models to analyse whether our results are dependent on EPS models, and find that the tendency of these two models is the same as that of Bruzual & Charlot models. Our results are independent of the EPS models. In addition, our test is based on old GCs and our conclusions may hold for old stellar population systems. Besides the age-metallicity degeneracy, we examine the possible effects of other factors (horizontal branch morphology, blue straggler stars, binary interactions and alpha-enhancement) and give a quantitative analysis of the influences of these factors on age determinations (except for alpha-enhancement). For the colour and spectrum-fitting methods, the age can be underestimated by about 0.0-3.0, 0.0-2.0 and 0.0-3.0Gyr owing to the influence of horizontal branch, blue straggler and binary stars, respectively. For the Lick-index method, the lower limit of maximal change of age is 6.0, 5.0 and 3.0 Gyr owing to the influence of horizontal branch, blue straggler and binary stars, respectively.
学科主题	Astronomy & Astrophysics
WOS标题词	Science & Technology ; Physical Sciences
类目[WOS]	Astronomy & Astrophysics
研究领域[WOS]	Astronomy & Astrophysics
关键词[WOS]	GALACTIC GLOBULAR-CLUSTERS ; HIGH-SPECTRAL-RESOLUTION ; EARLY-TYPE GALAXIES ; HORIZONTAL-BRANCH STARS ; SPACE-TELESCOPE OBSERVATIONS ; ELEMENT ABUNDANCE RATIOS ; LARGE-MAGELLANIC-CLOUD ; INITIAL MASS FUNCTION ; BLUE STRAGGLER STARS ; SUBDWARF-B-STARS
收录类别	SCI
原文出处	http://mnras.oxfordjournals.org/content/421/2/1678
语种	英语
WOS记录号	WOS:000302695600060
内容类型	期刊论文
源URL	[http://ir.ynao.ac.cn/handle/114a53/4540]
专题	云南天文台_大样本恒星演化研究组云南天文台_中国科学院天体结构与演化重点实验室
作者单位	1.National Astronomical Observatories/Yunnan Observatory, Chinese Academy of Sciences, Kunming, 650011, China 2.Graduate University of Chinese Academy of Sciences, Beijing, 100049, China 3.Key Laboratory for the Structure and Evolution of Celestial Objects, Chinese Academy of Sciences, Kunming, 650011, China 4.National Astronomical Observatories/Xinjiang Observatory, Chinese Academy of Sciences, Urumqi, 830011, China
推荐引用方式 GB/T 7714	Zhang Y,Han ZW,Liu, JZ,et al. Testing three derivative methods of stellar population synthesis models[J]. MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY,2012,421(2):1678-1696.
APA	Zhang Y,Han ZW,Liu, JZ,Zhang FH,&Kang XY.(2012).Testing three derivative methods of stellar population synthesis models.MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY,421(2),1678-1696.
MLA	Zhang Y,et al."Testing three derivative methods of stellar population synthesis models".MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 421.2(2012):1678-1696.