Signatures of Stellar Accretion in MaNGA Early-type Galaxies
文献类型:期刊论文
作者 | Oyarzún,Grecco A.1; Bundy,Kevin2; Westfall,Kyle B.2; Belfiore,Francesco2,3; Thomas,Daniel4; Maraston,Claudia4; Lian,Jianhui4; Aragón-Salamanca,Alfonso5; Zheng,Zheng6,7![]() |
刊名 | The Astrophysical Journal
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出版日期 | 2019-07-31 |
卷号 | 880期号:2 |
关键词 | Early-type galaxies Elliptical galaxies Galaxy accretion |
ISSN号 | 0004-637X |
DOI | 10.3847/1538-4357/ab297c |
英文摘要 | Abstract The late assembly of massive galaxies is thought to be dominated by stellar accretion in their outskirts (beyond two effective radii Re) due to dry, minor galaxy mergers. We use observations of 1010 passive early-type galaxies (ETGs) within z?0.15 from MaNGA (Mapping Nearby Galaxies at Apache Point Observatory) to search for evidence of this accretion. The outputs from the stellar population fitting codes FIREFLY, pPXF, and Prospector are compared to control systematic errors in stellar metallicity (Z) estimation. We find that the average radial log Z/Z⊙ profiles of ETGs in various stellar mass (M*) bins are not linear. As a result, these profiles are poorly characterized by a single gradient value, explaining why weak trends reported in previous work can be difficult to interpret. Instead, we examine the full radial extent of stellar metallicity profiles and find them to flatten in the outskirts of M*???1011 M⊙ ETGs. This is a signature of stellar accretion. Based on a toy model for stellar metallicity profiles, we infer the ex situ stellar mass fraction in ETGs as a function of M* and galactocentric radius. We find that ex situ stars at R?~?2Re make up 20% of the projected stellar mass of M*???1010.5M⊙ ETGs, rising up to 80% for M*???1011.5M⊙ ETGs. |
语种 | 英语 |
WOS记录号 | IOP:0004-637X-880-2-AB297C |
出版者 | The American Astronomical Society |
源URL | [http://ir.bao.ac.cn/handle/114a11/27208] ![]() |
专题 | 中国科学院国家天文台 |
作者单位 | 1.Astronomy Department, University of California, Santa Cruz, CA 95064, USA; goyarzun@ucsc.edu 2.University of California Observatories - Lick Observatory, University of California, Santa Cruz, CA 95064, USA 3.European Southern Observatory, Karl-Schwarzschild-Str. 2, Garching bei München, D-85748, Germany 4.Institute of Cosmology and Gravitation, University of Portsmouth, Burnaby Road, Portsmouth, PO1 3FX, UK 5.School of Physics and Astronomy, University of Nottingham, University Park, Nottingham, NG7 2RD, UK 6.National Astronomical Observatories, Chinese Academy of Sciences, A20 Datun Road, Beijing, People’s Republic of China 7.CAS Key Laboratory of FAST, NAOC, Chinese Academy of Sciences, People’s Republic of China 8.Energy Lancaster, Lancaster University, Lancaster LA14YB, UK 9.Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218, USA 10.McDonald Observatory, The University of Texas at Austin, 1 University Station, Austin, TX 78712, USA |
推荐引用方式 GB/T 7714 | Oyarzún,Grecco A.,Bundy,Kevin,Westfall,Kyle B.,et al. Signatures of Stellar Accretion in MaNGA Early-type Galaxies[J]. The Astrophysical Journal,2019,880(2). |
APA | Oyarzún,Grecco A..,Bundy,Kevin.,Westfall,Kyle B..,Belfiore,Francesco.,Thomas,Daniel.,...&Andrews,Brett H..(2019).Signatures of Stellar Accretion in MaNGA Early-type Galaxies.The Astrophysical Journal,880(2). |
MLA | Oyarzún,Grecco A.,et al."Signatures of Stellar Accretion in MaNGA Early-type Galaxies".The Astrophysical Journal 880.2(2019). |
入库方式: OAI收割
来源:国家天文台
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