A homogeneous analysis of disks around brown dwarfs
文献类型：期刊论文
| 作者 | Liu, Y.1,2 ; Joergens, V.3,4; Bayo, A.3,5; Nielbock, M.3; Wang, H.1,2
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| 刊名 | ASTRONOMY & ASTROPHYSICS
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| 出版日期 | 2015-10-01 |
| 卷号 | 582页码:0 |
| 关键词 | stars: low-mass circumstellar matter brown dwarfs protoplanetary disks |
| 英文摘要 | We re-analyzed the Herschel/PACS data of a sample of 55 brown dwarfs (BDs) and very low mass stars with spectral types ranging from M5.5 to L0. We investigated the dependence of disk structure on the mass of the central object in the substellar regime based on a homogeneous analysis of Herschel data from flux density measurements to spectral energy distribution (SED) modeling. The broadband SEDs were compiled by adding previous photometry at shorter wavelengths and (sub-)millimeter data. We performed detailed SED analysis for the 46 targets that show infrared (IR) excess emission using radiative transfer models and evaluated the constraints on the disk parameters through Bayesian inference. A systematic comparison between the derived disk properties and those of sun-like stars shows that the disk flaring of BDs and very low mass stars is generally smaller than that of their higher mass counterparts, the disk mass is orders of magnitude lower than the typical value found in T Tauri stars, and the disk scale heights are comparable in both sun-like stars and BDs. We further divided our sample into an early-type brown dwarf (ETBD) group and a late-type brown dwarf (LTBD) group by using spectral type (=M8) as the border criterion. We systematically compared the modeling results from Bayesian analysis between these two groups, and found the trends of flaring index as a function of spectral type also present in the substellar regime. The spectral type independence of the scale height is also seen between high-mass and very low-mass BDs. However, both the ETBD and LTBD groups feature a similar median disk mass of 1 x 10(-5) M-circle dot and no clear trend is visible in the distribution, probably due to the uncertainty in translating the far-IR photometry into disk mass, the detection bias and the age difference among the sample. Unlike previous studies, our analysis is completely homogeneous in Herschel/PACS data reduction and modeling with a statistically significant sample. Therefore, we present evidence of stellar-mass-dependent disk structure down to the substellar mass regime, which is important for planet formation models. |
| WOS标题词 | Science & Technology ; Physical Sciences |
| 学科主题 | 天文和天体物理 |
| 类目[WOS] | Astronomy & Astrophysics |
| 研究领域[WOS] | Astronomy & Astrophysics |
| 关键词[WOS] | LOW-MASS STARS ; TW-HYDRAE ASSOCIATION ; SCORPIUS OB ASSOCIATION ; SPECTRAL ENERGY-DISTRIBUTIONS ; YOUNG STELLAR OBJECTS ; INTERSTELLAR SILICATE MINERALOGY ; OPHIUCHI MOLECULAR CLOUD ; GOULD BELT SURVEY ; CIRCUMSTELLAR DISKS ; FORMING REGION |
| 收录类别 | SCI |
| 语种 | 英语 |
| WOS记录号 | WOS:000363538500022 |
| 源URL | [http://libir.pmo.ac.cn/handle/332002/14811]  |
| 专题 | 紫金山天文台_毫米波和亚毫米波技术实验室 |
| 作者单位 | 1.Chinese Acad Sci, Purple Mt Observ, Nanjing 210008, Jiangsu, Peoples R China 2.Chinese Acad Sci, Key Lab Radio Astron, Nanjing 210008, Jiangsu, Peoples R China 3.Max Planck Inst Astron, D-69117 Heidelberg, Germany 4.Heidelberg Univ, Zentrum Astron, Inst Theor Astrophys, D-69120 Heidelberg, Germany 5.Univ Valparaiso, Fac Ciencias, Dept Fis & Astron, Valparaiso, Chile |
| 推荐引用方式 GB/T 7714 | Liu, Y.,Joergens, V.,Bayo, A.,et al. A homogeneous analysis of disks around brown dwarfs[J]. ASTRONOMY & ASTROPHYSICS,2015,582:0. |
| APA | Liu, Y.,Joergens, V.,Bayo, A.,Nielbock, M.,&Wang, H..(2015).A homogeneous analysis of disks around brown dwarfs.ASTRONOMY & ASTROPHYSICS,582,0. |
| MLA | Liu, Y.,et al."A homogeneous analysis of disks around brown dwarfs".ASTRONOMY & ASTROPHYSICS 582(2015):0. |
入库方式： OAI收割
来源：紫金山天文台
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