We aim to study spatial and kinematic substructures of the region encompassed by Upper Scorpius and Ophiuchus star-forming regions, determining dynamical traceback ages and studying the star formation history of the complex. We identified seven different groups in this region. Four groups (nu Sco, beta Sco, sigma Sco and delta Sco) are part of Upper Scorpius, two groups (rho Oph and alpha Sco) are in Ophiuchus, and another group (pi Sco) is a nearby young population. We found an age gradient from the rho Oph group (the youngest) to the delta Sco group (<~5 Myr), showing that star formation was a sequential process for the past 5 Myr. Our traceback analysis shows that Upper Scorpius and rho Oph groups share a common origin. The closer group of pi Sco is probably older, and the traceback analysis suggests that this group and the alpha Sco group have a different origin, likely related to other associations in the Sco-Cen complex. Our study shows that this region has a complex star formation history that goes beyond the current formation scenario, likely a result of stellar feedback from massive stars, supernovae explosions, and dynamic interactions between stellar groups and the molecular gas. In particular, we speculate that photo-ionisation from the massive delta Sco star could have triggered star formation first in the beta Sco group and then in the nu Sco group. The perturbations of stellar orbits due to stellar feedback and dynamical interactions could also be responsible for the 1-3 Myr difference that we found between dynamical traceback ages and isochronal ages.
Dust masses of disks around 8 Brown Dwarfs and Very Low-Mass Stars in Upper Sco OB1 and Ophiuchus
本文介绍了ALMA波段7对天蝎座OB 1上的7个天体和蛇夫座的1颗M3星的尘埃和CO气体的观测结果，这些天体的光谱类型在M5.5和M7.5之间。我们检测到未解决的连续发射，但一个源，和$^{12}$ CO J=3-2线在两个源。我们约束这些系统的尘埃和气体的含量使用网格的模型计算的辐射转移代码MCFOST，并找到磁盘尘埃质量之间的0.1和1 M $_\oplus$，这表明恒星质量/磁盘质量的相关性可以外推的质量低至0.05 M $_\odot$的褐矮星。我们在上斯科探测到CO排放的一个圆盘，2 MASS J15555600，也是具有最温暖的内部圆盘的圆盘，如其H - [4.5]光度颜色所示。使用我们的辐射转移网格，我们扩展恒星光度和质量平均磁盘尘埃温度之间的相关性最初来自恒星质量的物体到棕矮星制度的$\langle T_{dust} \rangle \approx 22 (L_{*} /L_{\odot})^{0.16} K$，适用于光谱类型的M5和以后。这比早期光谱型天体的关系略浅，产生较温暖的低质量盘。两种处方在0.27 L $_\odot$交叉，对应于0.1和0.2 M $_\odot$之间的质量，取决于年龄。
Disk fraction among free-floating planetary-mass objects in Upper Scorpius
Univ. de Bordeaux（波尔多大学）；Institut universitaire de France (IUF)（法国大学学院）；Laboratoire d’Astrophysique de Bordeaux, Univ. de Bordeaux, CNRS（波尔多大学 Astrophysics 实验室，CNRS）；Instituto de Astrofísica de Canarias（加那利天体物理研究所）；Université Paris-Saclay, Université Paris Cité, CEA, CNRS（萨克雷大学，巴黎西岱大学，CEA，CNRS）；Universidad Nacional de Educación a Distancia (UNED)（西班牙国立远程教育大学）；Centro de Astrobiología (CAB), CSIC-INTA（天体生物学中心，CSIC-INTA）；The University of Tokyo（东京大学）；Astrobiology Center（天体生物学中心）
Investigating the Upper Scorpius OB association with HERMES. I. The spectroscopic sample and 6D kinematics
Chalmers University of Technology（查尔姆斯理工大学）；Keele University（基尔大学）；University of Ljubljana（卢布尔雅那大学）；INAF – Osservatorio Astronomico di Trieste（意大利国家天体物理研究所的里雅斯特天文台）；Research School of Astronomy and Astrophysics, Australian National University（澳大利亚国立大学天文与天体物理研究学院）；Instituto de Estudios Astrofı́sicos, Facultad de Ingenierı́a y Ciencias, Universidad Diego Portales（迭戈帕托莱斯大学工程与科学学院天体物理研究所）
The evolution of velocity dispersion in the Sco-Cen OB association
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）；University of Vienna（维也纳大学）；Center for Astrophysics | Harvard & Smithsonian（哈佛-史密森天体物理中心）；Univ. de Barcelona (UB)（巴塞罗那大学）；Institut de Ciències del Cosmos (ICCUB)（宇宙科学研究所）
The star formation history of Orion is structured and episodic
University of Vienna（维也纳大学）；Faculty of Physics, Martí i Franquès, 1-11, 08028 Barcelona, Spain（巴塞罗那大学物理学院）；Astronomical Institute of the Czech Academy of Sciences（捷克科学院天文研究所）；Center for Astrophysics | Harvard & Smithsonian（哈佛-史密森尼天体物理中心）；European Southern Observatory（欧洲南方天文台）
