Stellar Population Properties of Ultracompact Dwarfs in M87: A Mass-Metallicity Correlation Connecting Low-metallicity Globular Clusters and Compact Ellipticals

doi:10.3847/1538-4357/aab88a

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	Stellar Population Properties of Ultracompact Dwarfs in M87: A Mass-Metallicity Correlation Connecting Low-metallicity Globular Clusters and Compact Ellipticals
	Zhang, Hong-Xin 1,2; Puzia, Thomas H.1; Peng, Eric W.3,4; Liu, Chengze 5,6; Cote, Patrick 7; Ferrarese, Laura 7; Duc, Pierre-Alain 8; Eigenthaler, Paul 1; Lim, Sungsoon 3,4; Lancon, Ariane 9
刊名	ASTROPHYSICAL JOURNAL
	2018-05-01
卷号	858 期号:1 页码:11
关键词	galaxies: clusters: individual (Virgo) galaxies: dwarf galaxies: formation galaxies: star clusters: general galaxies: stellar content globular clusters: general
ISSN号	0004-637X
DOI	10.3847/1538-4357/aab88a
英文摘要	We derive stellar population parameters for a representative sample of ultracompact dwarfs (UCDs) and a large sample of massive globular clusters (GCs) with stellar masses greater than or similar to 10(6) Me in the central galaxy M87 of the Virgo galaxy cluster, based on model fitting to the Lick-index measurements from both the literature and new observations. After necessary spectral stacking of the relatively faint objects in our initial sample of 40 UCDs and 118 GCs, we obtain 30 sets of Lick-index measurements for UCDs and 80 for GCs. The M87 UCDs have ages greater than or similar to 8 Gyr and [alpha/Fe] similar or equal to 0.4 dex, in agreement with previous studies based on smaller samples. The literature UCDs, located in lower-density environments than M87, extend to younger ages and smaller [alpha/Fe] (at given metallicities) than M87 UCDs, resembling the environmental dependence of the stellar nuclei of dwarf elliptical galaxies (dEs) in the Virgo cluster. The UCDs exhibit a positive mass-metallicity relation (MZR), which flattens and connects compact ellipticals at stellar masses greater than or similar to 10(8) M-circle dot. The Virgo dE nuclei largely follow the average MZR of UCDs, whereas most of the M87 GCs are offset toward higher metallicities for given stellar masses. The difference between the mass-metallicity distributions of UCDs and GCs may be qualitatively understood as a result of their different physical sizes at birth in a self-enrichment scenario or of galactic nuclear cluster star formation efficiency being relatively low in a tidal stripping scenario for UCD formation.. The existing observations provide the necessary but not sufficient evidence for tidally stripped dE nuclei being the dominant contributors to the M87 UCDs.
资助项目	FONDECYT Postdoctoral grant[3160538] ; FONDECYT Regular Project[1161817] ; BASAL Center for Astrophysics and Associated Technologies[PFB-06] ; CAS Pioneer Hundred Talents Program ; NSFC[11673017] ; NSFC[11203017] ; NSFC[11433002] ; Key Laboratory for Particle Physics, Astrophysics and Cosmology, Ministry of Education ; National Natural Science Foundation of China[11573002]
WOS关键词	ELEMENT ABUNDANCE RATIOS ; EARLY-TYPE GALAXIES ; FORNAX CLUSTER ; STAR-CLUSTERS ; VIRGO CLUSTER ; LOCAL UNIVERSE ; LICK INDEXES ; BLACK-HOLES ; SYSTEMS ; AGES
WOS研究方向	Astronomy & Astrophysics
语种	英语
出版者	IOP PUBLISHING LTD
WOS记录号	WOS:000431458900008
资助机构	FONDECYT Postdoctoral grant ; FONDECYT Postdoctoral grant ; FONDECYT Regular Project ; FONDECYT Regular Project ; BASAL Center for Astrophysics and Associated Technologies ; BASAL Center for Astrophysics and Associated Technologies ; CAS Pioneer Hundred Talents Program ; CAS Pioneer Hundred Talents Program ; NSFC ; NSFC ; Key Laboratory for Particle Physics, Astrophysics and Cosmology, Ministry of Education ; Key Laboratory for Particle Physics, Astrophysics and Cosmology, Ministry of Education ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; FONDECYT Postdoctoral grant ; FONDECYT Postdoctoral grant ; FONDECYT Regular Project ; FONDECYT Regular Project ; BASAL Center for Astrophysics and Associated Technologies ; BASAL Center for Astrophysics and Associated Technologies ; CAS Pioneer Hundred Talents Program ; CAS Pioneer Hundred Talents Program ; NSFC ; NSFC ; Key Laboratory for Particle Physics, Astrophysics and Cosmology, Ministry of Education ; Key Laboratory for Particle Physics, Astrophysics and Cosmology, Ministry of Education ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; FONDECYT Postdoctoral grant ; FONDECYT Postdoctoral grant ; FONDECYT Regular Project ; FONDECYT Regular Project ; BASAL Center for Astrophysics and Associated Technologies ; BASAL Center for Astrophysics and Associated Technologies ; CAS Pioneer Hundred Talents Program ; CAS Pioneer Hundred Talents Program ; NSFC ; NSFC ; Key Laboratory for Particle Physics, Astrophysics and Cosmology, Ministry of Education ; Key Laboratory for Particle Physics, Astrophysics and Cosmology, Ministry of Education ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; FONDECYT Postdoctoral grant ; FONDECYT Postdoctoral grant ; FONDECYT Regular Project ; FONDECYT Regular Project ; BASAL Center for Astrophysics and Associated Technologies ; BASAL Center for Astrophysics and Associated Technologies ; CAS Pioneer Hundred Talents Program ; CAS Pioneer Hundred Talents Program ; NSFC ; NSFC ; Key Laboratory for Particle Physics, Astrophysics and Cosmology, Ministry of Education ; Key Laboratory for Particle Physics, Astrophysics and Cosmology, Ministry of Education ; National Natural Science Foundation of China ; National Natural Science Foundation of China
内容类型	期刊论文
源URL	[http://ir.bao.ac.cn/handle/114a11/21233]
专题	中国科学院国家天文台
通讯作者	Zhang, Hong-Xin
作者单位	1.Pontificia Univ Catolica Chile, Inst Astrophys, Av Vicuna Mackenna 4860, Santiago 7820436, Chile 2.Univ Sci & Technol China, Dept Astron, CAS Key Lab Res Galaxies & Cosmol, Hefei 230026, Anhui, Peoples R China 3.Peking Univ, Dept Astron, Beijing 100871, Peoples R China 4.Peking Univ, Kavli Inst Astron & Astrophys, Beijing 100871, Peoples R China 5.Shanghai Jiao Tong Univ, Shanghai Key Lab Particle Phys & Cosmol, Dept Astron, Shanghai 200240, Peoples R China 6.Shanghai Jiao Tong Univ, Shanghai Key Lab Particle Phys & Cosmol, Shanghai 200240, Peoples R China 7.NRC Herzberg Astron & Astrophys Res Ctr, 5071 West Saanich Rd, Victoria, BC V9E 2E7, Canada 8.Univ Strasbourg, CNRS, Observ Astron Strasbourg, UMR 7550, F-67000 Strasbourg, France 9.Univ Strasbourg, CNRS, Observ Astron Strasbourg, UMR 7550, 11 Rue Univ, F-67000 Strasbourg, France 10.NRC Herzberg Astron & Astrophys, 5071 West Saanich Rd, Victoria, BC V9E 2E7, Canada
推荐引用方式 GB/T 7714	Zhang, Hong-Xin,Puzia, Thomas H.,Peng, Eric W.,et al. Stellar Population Properties of Ultracompact Dwarfs in M87: A Mass-Metallicity Correlation Connecting Low-metallicity Globular Clusters and Compact Ellipticals[J]. ASTROPHYSICAL JOURNAL,2018,858(1):11.
APA	Zhang, Hong-Xin.,Puzia, Thomas H..,Peng, Eric W..,Liu, Chengze.,Cote, Patrick.,...&Yu, Jincheng.(2018).Stellar Population Properties of Ultracompact Dwarfs in M87: A Mass-Metallicity Correlation Connecting Low-metallicity Globular Clusters and Compact Ellipticals.ASTROPHYSICAL JOURNAL,858(1),11.
MLA	Zhang, Hong-Xin,et al."Stellar Population Properties of Ultracompact Dwarfs in M87: A Mass-Metallicity Correlation Connecting Low-metallicity Globular Clusters and Compact Ellipticals".ASTROPHYSICAL JOURNAL 858.1(2018):11.