Surround & Squash: The Interstellar Medium around Scorpius Centaurus OB2
Martin G. H. Krause, Andreas Burkert, Roland Diehl, Katharina Fierlinger, Benjamin Gaczkowski, Daniel Kroell, Judith Ngoumou, Veronica Roccatagliata, Thomas Sie… 展开作者
Martin G. H. Krause, Andreas Burkert, Roland Diehl, Katharina Fierlinger, Benjamin Gaczkowski, Daniel Kroell, Judith Ngoumou, Veronica Roccatagliata, Thomas Siegert, Thomas Preibisch
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14 pages, 11 figures, accepted by Astronomy & Astrophysics
We exploited observational constraints on stars, gas and nucleosynthesis ashes for the closest region of recent massive-star formation, Scorpius-Centaurus OB2, and combined them with 3D hydrodynamical simulations, in order to address physics and history for the case of the Scorpius-Centaurus superbubble. We used published cold gas observations through PLANCK survey data processing, HERSCHEL and APEX, continuum and molecular line observations. We analysed the Galactic All Sky Survey (GASS) to investigate shell structures in atomic hydrogen, and used HIPPARCOS and Gaia data in combination with interstellar absorption against stars to obtain new constraints for the distance to the Hi features. Hot gas is traced in soft X-rays via the ROSAT all sky survey. Nucleosynthesis ejecta from massive stars were traced with new INTEGRAL spectrometer observations via 26Al radioactivity. We also performed 3D hydrodynamical simulations for the Sco-Cen superbubble. To investigate the impact of massive star feedback on extended clouds, we simulate the interaction of a turbulent cloud with the hot, pressurised gas in a superbubble. The hot gas fills the tenuous regions of the cloud and compresses the denser parts. Stars formed in these dense clumps would have distinct spatial and kinematic distributions. The combined results from observations and simulations are consistent with a scenario where dense gas was initially distributed in a band elongated in the direction now occupied by the OB association. Superbubbles powered by massive stars would then repeatedly break out of the elongated parent cloud, surround and squash the denser parts of the gas sheet and thus induce more star formation. The expected spatial and kinematic distribution of stars is consistent with observations of Sco-Cen. The scenario might apply to many similar regions in the Galaxy and also to AGN-related superbubbles.
The Kinematics of the Scorpius-Centaurus OB Association from Gaia DR1
我们提出了一个运动学研究的天蝎座，半人马座（Sco Cen）OB协会（Sco OB 2）使用盖亚DR 1松弛和自行。我们的目标是测试的经典理论，OB协会是密集和紧凑的星团被破坏的过程，如残余气体排出的扩展残余。该协会433名成员中有258名成员可以使用盖亚天体测量法，其余成员使用经修订的依巴谷天体测量法。我们使用这些数据来证实，这三个小组的Sco-Cen的引力不受约束，并具有非各向同性的速度色散，这表明他们还没有时间动态放松。我们还探讨了内部的运动学的子群，以寻找证据的扩张。我们测试Blaauw的经典线性膨胀模型，搜索沿银河系轴的速度趋势，比较膨胀和非膨胀收敛点，进行回溯分析，假设两个线性轨迹，并使用epicentric近似，并评估证据膨胀在适当的运动校正虚拟膨胀/收缩。这些方法都没有提供一致的证据，扩大的亚组，没有证据表明，亚组有一个更紧凑的配置在过去。我们发现的证据，支持的观点，他们不是由个别星团的中断形成的亚组内的运动学结构。我们的结论是，天蝎座-Cen可能出生高度亚结构，多个小规模的恒星形成事件有助于整体OB协会，而不是单一的，整体的集群恒星形成的爆发。
A HARPS radial velocity search for planets in the Scorpius-Centaurus association. And its combination with the HARPS and SOPHIE young nearby stars (YNS) surveys
A kinematic study and membership analysis of the Lupus star-forming region
本文致力于研究狼疮年轻恒星运动群的运动学性质，其主要目的是推导出每个群成员的运动方程。我们确定这些恒星在狼疮恒星形成区域，定义年轻恒星的共动协会，利用我们新的和改进的收敛点搜索方法，使我们能够获得精确的位置的共动协会从恒星的自行。我们使用已发表的自行目录，并搜索径向速度的文献，这是需要计算个人的视差。我们补充了径向速度数据与新的测量光谱观测与FEROS摄谱仪安装在MPG/ESO 2.2米望远镜在拉西拉。我们确定了一个共动组与109个前主序星和候选人，定义的运动学性质的狼疮低质量恒星形成区域。我们推导出已知径向速度的恒星的个别弛豫，并假设所有恒星都有相同的空间运动，从而推导出其余恒星的试探性弛豫。收敛点法结合k-NN算法，使得有可能将狼座和上半人马座狼座恒星与相邻的天蝎座-半人马座星协区分开来。我们发现显着的深度效应在这个地区，并表明，经典的金牛座T星，位于附近的狼疮分子云，形成一个背景人口，而弱发射线金牛座T星分散不仅在角度范围内，而且在深度。在即将发表的一篇论文中，新得出的单个行星将被用于改进Lupus T Tauri恒星的质量和年龄，目的是更好地限制其拱星，原行星盘的寿命。
Precise determination of circumstellar disk lifetimes: Disk evolution in a single star-forming region
University of Vienna（维也纳大学）；European Southern Observatory（欧洲南方天文台）；Center for Astrophysics | Harvard & Smithsonian（哈佛-史密森天体物理中心）；Astronomical Institute of the Czech Academy of Sciences（捷克科学院天文研究所）；Universität zu Köln（科隆大学）
