Exposure of details of the formation of massive stars

曝光大质量恒星形成的细节

• 批准号: 64018249
• 负责人: Privatdozentin Dr. Katharina Schreyer
• 金额: --
• 依托单位: Astrophysikalisches Institut und Universitätssternwarte
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2008
• 资助国家: 德国
• 起止时间: 2007-12-31 至 2013-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/64018249?language=en
• 关键词: Exposure; details; formation; massive; stars

The birth process of massive stars is one of the unresolved mysteries of present research in star formation. Whether the dominant formation process for massive stars is disk accretion or coalescence is still an open question. The goal of this project is to resolve details of this process in terms of interferometric observations in the mm wavelength range. In a first step, we focus on already available data. Due to successful recent measurements with the VLA and the Plateau de Bure Interferometer, we detected different molecular species in the close vicinity of a 8-10M⊙-star (AFGL 490). A first look at the observational data implies on-going gas infall towards a disk-like structure with a radius of 1500 AU. Additionally newly discovered bow shocks along the line of the high-velocity outflow support evidence for on-going non-steady state mass accretion. In terms of modeling of the observational results, we would like to estimate physical properties of the detected gas (temperature and density profile, gas motion) as well as the mass accretion rate. Furthermore, we intend to study the nature of a dense 20 000 AU large bar-like gas structure perpendicularly located to the high-velocity outflow and centered at the massive star. We want to answer the question which role this gas bar (or disk ?) plays during the star formation. In a second step of our project, we would like to extend our search for comparable structures around more luminous, very young stars to find out whether these structures are common features during massive star formation or a special configuration in case of our selected target.

大质量恒星的诞生过程是目前恒星形成研究中未解之谜之一。大质量恒星的主要形成过程是盘吸积还是合并仍然是一个悬而未决的问题。该项目的目标是通过毫米波长范围内的干涉观测来解决该过程的细节。第一步，我们关注现有的数据。由于最近使用 VLA 和 Plateau de Bure 干涉仪进行的成功测量，我们在 8-10M⊙ 星 (AFGL 490) 附近检测到了不同的分子种类。乍一看观测数据表明气体正在向半径为 1500 个天文单位的盘状结构流入。此外，沿着高速流出线新发现的弓形激波也支持了正在进行的非稳态质量吸积的证据。在观测结果的建模方面，我们希望估计检测到的气体的物理特性（温度和密度分布、气体运动）以及质量吸积率。此外，我们打算研究垂直于高速外流并以大质量恒星为中心的密集 20 000 天文单位大型棒状气体结构的性质。我们想要回答这个气体条（或圆盘？）在恒星形成过程中扮演什么角色的问题。在我们项目的第二步中，我们希望扩大对更明亮、非常年轻的恒星周围类似结构的搜索，以确定这些结构是否是大质量恒星形成过程中的常见特征，或者是我们选择的目标的特殊配置。

项目成果

Multi-site campaign for transit timing variations of WASP-12 b: possible detection of a long-period signal of planetary origin

• DOI: 10.1051/0004-6361/201220739
• 发表时间: 2013-01
• 期刊: Astronomy and Astrophysics
• 影响因子: 6.5
• 作者: G. Maciejewski;Dinko Dimitrov;M. Seeliger;S. Raetz;Ł. Bukowiecki;M. Kitze;R. Errmann;Grzegorz Nowak;Andrzej Niedzielski;V. Popov;C. Marka;K. Goździewski;Ralph Neuhäuser;J. Ohlert;T. Hinse;J. W. Lee;C.‐U. Lee;Joh-Na Yoon;A. Berndt;H. Gilbert;C. Ginski;M. Hohle;M. Mugrauer;T. Roell;T. Schmidt;N. Tetzlaff;L. Mancini;J. Southworth;M. Dall’ora;S. Ciceri;R. Zambelli;G. Corfini;Hiromitsu Takahashi;K. Tachihara;J. Benkő;K. Sárneczky;Gy. M. Szabó;Gy. M. Szabó;T. Varga;M. Vaňko;Y. Joshi;Wen-Ping Chen

Is there a compact companion orbiting the late O-type binary star HD 164816?

• DOI: 10.1111/j.1365-2966.2012.22011.x
• 发表时间: 2012-09
• 期刊: Monthly Notices of the Royal Astronomical Society
• 影响因子: 4.8
• 作者: L. Trepl;V. Hambaryan;T. Pribulla;N. Tetzlaff;R. Chini;R. Neuhauser;S. Popov;O. Stahl;F. Walter-F.

Tracing the evolutionary stage of Bok globules: CCS and NH 3

追踪 Bok 小球的演化阶段：CCS 和 NH 3

• DOI: 10.1051/0004-6361/201014375
• 发表时间: 2012
• 期刊: Astronomy and Astrophysics
• 影响因子: 6.5
• 作者: Schreyer;Launhardt;Semenov;Henning
• 通讯作者: Henning