We have performed simulations of cluster formation along two regions of a spiral arm taken from a global Milky Way simulation, including photoionising feedback. One region is characterised by strongly converging flows, the other represents a more typical spiral arm region. We find that more massive clusters are able to form on shorter timescales for the region with strongly converging flows. Mergers between clusters are frequent in the case of the strongly converging flows and enable the formation of massive clusters. We compare equivalent clusters formed in simulations with and without ionisation. Photoionisation does not prevent massive cluster formation, but can be seen to limit the masses of the clusters. On average the mass is reduced by around 20%, but we see a large spread from ionisation having minimal difference to leading to a 50% reduction in mass. Photoionisation is also able to clear out the gas in the vicinity of the clusters on Myr timescales, which can produce clusters with larger radii that are surrounded by more massive stellar halos. We find that the ionising feedback has more impact in our second region which is less dense and has less strongly converging flows.
Can diffuse X-rays be important in driving photoionisation in molecular clouds?
Max Planck Institute for Extraterrestrial Physics(马克斯·普朗克地外物理研究所);Physics Department, Technion - Israel Institute of Technology(以色列理工学院物理系);Faculty of Physics, University of Duisburg-Essen(杜伊斯堡-埃森大学物理学院);INAF–Osservatorio Astrofisico di Arcetri(意大利国家天体物理研究所阿切特里天文台)
Converging on the eccentricity of massive black hole binaries in galactic mergers
School of Mathematics and Physics, University of Surrey(萨里大学数学与物理学院);Dipartimento di Fisica “G. Occhialini(意大利国家核物理研究所米兰比可卡分部);INFN, Sezione di Milano-Bicocca(海德堡大学天文学计算中心);Astronomisches Rechen-Institut, Zentrum für Astronomie der Universität Heidelberg
Signatures of star formation inside galactic outflows
University of Cambridge(剑桥大学);Kavli Institute for Cosmology, University of Cambridge(剑桥大学卡弗里宇宙学研究所);Institute of Astronomy, University of Cambridge(剑桥大学天文研究所);University College London(伦敦大学学院);Centro de Astrobiología (CAB), CSIC-INTA(天体生物学中心(CAB),西班牙国家科学研究委员会-国家航空航天技术研究所);European Southern Observatory(欧洲南方天文台);INAF– Arcetri Astrophysical Observatory(意大利国家天体物理研究所-阿切特里天文台);Universidad Complutense de Madrid(马德里康普顿斯大学);Scuola Normale Superiore(比萨高等师范学院);Instituto de Astrofísica de Andalucía (IAA-CSIC)(安达卢西亚天体物理研究所(IAA-CSIC));University of Zurich(苏黎世大学);Istituto Ricerche Solari (IRSOL), Universita della Svizzera italiana (USI)(瑞士意大利大学太阳研究研究所(IRSOL));Università degli Studi di Firenze(佛罗伦萨大学);University of Nottingham(诺丁汉大学);Max-Planck-Institut für extraterrestrische Physik(马克斯·普朗克地外物理学研究所)
HII-CHI-mistry for active galactic nuclei: optical sulphur abundances without empirical ionisation correction factors
Universidade do Vale do Paraíba(帕拉伊巴山谷大学);Astronomisches Rechen-Institut, Zentrum für Astronomie der Universität Heidelberg(海德堡大学天文学计算中心);Main Astronomical Observatory, National Academy of Sciences of Ukraine(乌克兰国家科学院主天文台);INAF - Osservatorio Astronomico di Roma(意大利国家天体物理研究所罗马天文台)
Stellar feedback in M83 as observed with MUSE -- I. Overview, an unprecedented view of the stellar and gas kinematics and evidence of outflowing gas
我们提出了一个大的VLT/MUSE马赛克(3.8 × 3.8千秒差距)附近的旋涡星系M83,空间分辨率约20秒差距。我们得到了恒星和电离气体的运动学,并与ALMA CO(2-1)的分子气体运动学进行了比较。我们将电离气体分为HII区和扩散电离气体(DIG),并确定了来自DIG的Ha光度分数(f_DIG)。我们观察到,恒星和气体跟踪银河系盘旋转,以及快速旋转的核组件,可能连接到长期的过程驱动的银河酒吧。在气体运动学中,我们观察到原子核以东的气流,相对于圆盘发生了红移。该流被一个扩展的电离气体区域所包围,该电离气体区域具有增强的速度分散和高电离状态,这在很大程度上与被慢冲击电离一致。我们解释这一功能的叠加盘和平面外层的DIG,或作为一个酒吧驱动的冲击气体流入。一个双高斯分量拟合的Ha线也揭示了存在一个核的双锥结构,其对称轴是垂直于酒吧。这两个锥沿着视线出现蓝移和红移,并突出具有Ha发射,其与盘的分离高达200 km s-1,以及高速色散~80-200 km s-1。在锥体的远端,我们观察到气体与被冲击电离一致。这些特征以前从未在M83中观察到过;我们假设它们是在追踪一个恒星暴驱动的外流,冲击周围的ISM。最后,我们在我们的视野中获得f_DIG ~ 13%。我们检查发射的HII地区和DIG的“BPT”图,发现在HII地区的光电离占99.8%的哈通量,而DIG有混合贡献的光电离(94.9%…