While the importance of supernova feedback in galaxies is well established, its role on the scale of molecular clouds is still debated. In this work, we focus on the impact of supernovae on individual clouds, using a high-resolution magneto-hydrodynamic simulation of a region of 250 pc where we resolve the formation of individual massive stars. The supernova feedback is implemented with real supernovae that are the natural evolution of the resolved massive stars, so their position and timing are self-consistent. We select a large sample of molecular clouds from the simulation to investigate the supernova energy injection and the resulting properties of molecular clouds. We find that molecular clouds have a lifetime of a few dynamical times, less then half of them contract to the point of becoming gravitationally bound, and the dispersal time of bound clouds, of order one dynamical time, is a factor of two shorter than that of unbound clouds. We stress the importance of internal supernovae, that is massive stars that explode inside their parent cloud, in setting the cloud dispersal time, and their huge overdensity compared to models where the supernovae are randomly distributed. We also quantify the energy injection efficiency of supernovae as a function of supernova distance to the clouds. We conclude that intermittent driving by supernovae can maintain molecular-cloud turbulence and may be the main process of cloud dispersal. The role of supernovae in the evolution of molecular clouds cannot be fully accounted for without a self-consistent implementation of their feedback.
Possible Explosive Dispersal Outflow in IRAS 16076-5134 revealed with ALMA
我们提出了从阿塔卡马大型毫米/亚毫米阵列(ALMA)档案中检索到的0.9 mm连续谱和CO(3-2)线发射观测结果,这些观测结果指向大质量恒星形成区IRAS 16076-5134。我们确定了14个致密的核心,质量在0.3到22 M之间$_{\odot}$。我们发现了一个从-62到+83 km s $^{-1}$的类顺时针CO(3-2)喷射的集合,这些喷射似乎是从一个共同的中心位置径向产生的,靠近致密的核心MM 8。暗条系综在天空平面上呈准各向同性分布。几个细丝的径向速度遵循线性速度梯度,从一个共同的原点增加。考虑到整个丝状体系综,我们估计其总质量为138和216 M $_{\odot}$从其CO排放,分别为70 K和140 K。此外,假设一个恒定的速度扩张的细丝(83公里秒$^{-1}$),我们估计的动力学年龄流出的材料(3500年),它的动量(~10 $^{4}$ M $_{\odot}$公里秒$^{-1}$)和它的动能(~10 $^{48-49}$尔格)。由细丝呈现的形态学和运动学表明在IRAS 16076-5134中存在具有爆炸特征的分散外流。此外,我们作出了一个原始的估计的下限的爆炸性扩散流出的频率在银河系(每110年一次)考虑恒定的恒星形成率和效率相对于银河系的银河系中心半径。这可能意味着扩散外流和超新星的速度相当(大约每50年一次),这可能对星际介质的能量收支以及扩散外…
Star Formation Efficiency and Dispersal of Giant Molecular Clouds with UV Radiation Feedback: Dependence on Gravitational Boundedness and Magnetic Fields
Are supernovae driving turbulence in the solar neighborhood?
Université Paris-Saclay(巴黎萨克雷大学);Université Paris Cité(巴黎西岱大学);CEA(法国原子能和替代能源委员会);CNRS(法国国家科学研究中心);University of Vienna(维也纳大学);ENS de Lyon(里昂高等师范学校);Universite Claude Bernard Lyon 1(里昂第一大学);Universität Heidelberg(海德堡大学);Laboratoire de Physique de l’Ecole Normale Supérieure(巴黎高等师范学院物理实验室);ENS(巴黎高等师范学院);Université PSL(巴黎文理研究大学);Sorbonne Université(索邦大学);Observatoire de Paris(巴黎天文台);INAF - Istituto di Astrofisica e Planetologia Spaziali(意大利国家天体物理研究所);Università di Roma Tor Vergata(罗马托尔维加塔大学)
Cascading from the winds to the disk: the universality of supernovae-driven turbulence in different galactic interstellar media
University of California, Santa Cruz(加州大学圣克鲁兹分校);Canadian Institute for Theoretical Astrophysics, University of Toronto(加拿大理论天体物理研究所,多伦多大学);Princeton University(普林斯顿大学)
The Impact of Type Ia Supernovae in Quiescent Galaxies: II. Energetics and Turbulence
Ia型超新星(SNe Ia)在静止星系中提供了独特而重要的反馈,但它们的影响却被低估了。在本文中,我们分析了一系列高分辨率的模拟研究的能量和湍流的介质下SNe Ia。我们发现,当SN残留物被解决,它们的效果明显不同于体积加热项,因为通常假设在未解决的模拟。首先,净加热显著高于预期,每冷却时间增加30 $\pm$ 10\%。这是因为大部分介质被推入低密度,冷却效率低。其次,介质是湍流的;气体的均方根(RMS)速度为20-50 km s $^{-1}$,驱动尺度为数十秒差距。介质的速度场主要是由压缩模式,这是由3-7倍的螺线管组件大。第三,热气体具有非常宽的密度分布。密度波动与均方根马赫数之比(参数表示为$b$)为2-20。这与先前的湍流介质模拟相反,该模拟发现$b\lesssim$ 1。产生这种差异的原因主要是Ia型超新星的\textit{localized}发热造成的,它产生了较大的密度反差。最后,密度波动的典型长度尺度随时间增长,形成越来越大的气泡和边界脊。在解释X射线观测结果时,需要考虑这些潜在的密度波动。
The ALMA carbon monoxide supernova (ACOS) survey II. Turbulent giant molecular clouds at the positions of core-collapse supernovae
Adam Mickiewicz University(亚当·密茨凯维奇大学);Instituto de Astrofísica de Canarias(加那利天体物理研究所);Universidad de La Laguna (ULL)(拉帕卢纳大学);Stockholm University(斯德哥尔摩大学);Foundation for Research and Technology-Hellas(希腊研究与技术基金会);National and Kapodistrian University of Athens(雅典国立卡波季斯特里安大学);University of Costa Rica(哥斯达黎加大学);Institute of Space Sciences (ICE, CSIC)(空间科学研究所);Institut d’Estudis Espacials de Catalunya (IEEC)(加泰罗尼亚空间研究学院);University of Copenhagen(哥本哈根大学)
Computational advances and challenges in simulations of turbulence and star formation
Research School of Astronomy and Astrophysics, Australian National University(澳大利亚国立大学天体物理与天文研究学院);Astronomy Department, The University of Texas at Austin(德克萨斯大学奥斯汀分校天文系)
A "universal" supernova efficiency to drive the HI turbulence in nearby star-forming galaxies
University of Oulu(奥卢大学);DARK, Niels Bohr Institute, University of Copenhagen(哥本哈根大学尼尔斯·玻尔研究所DARK);Institut de Ciències del Cosmos (ICCUB), Universitat de Barcelona(巴塞罗那大学宇宙科学研究所);INAF – Padova Astronomical Observatory(意大利国家天体物理研究所帕多瓦天文台)