Supersonic turbulence in the interstellar medium (ISM) is closely linked to the formation of stars, and hence many theories connect the stellar initial mass function (IMF) with the turbulent properties of molecular clouds. Here we test three turbulence-based IMF models (by Padoan & Nordlund 2002, Hennebelle & Chabrier 2008, and Hopkins 2012), which predict the relation between the high-mass slope ($Γ$) of the IMF, $\mathrm{d} N/\mathrm{d} \log M \propto M^Γ$ and the exponent n of the velocity power spectrum of turbulence, $E_v(k)\propto k^{-n} $, where $n\approx 2$ corresponds to typical ISM turbulence. Using hydrodynamic simulations, we drive turbulence with an unusual index of $n\approx 1$, measure $Γ$, and compare the results with $n\approx 2$. We find that reducing $n$ from 2 to 1 primarily changes the high-mass region of the IMF (beyond the median mass), where we measure high-mass slopes within the 95 per cent confidence interval of $-1.5<Γ<-1$ for $n \approx 1$ and $-3.7<Γ<-2.4$ for $n\approx 2$, respectively. Thus, we find that $n=1$ results in a significantly flatter high-mass slope of the IMF, with more massive stars formed than for $n \approx 2$. We compare these simulations with the predictions of the three IMF theories. We find that while the Padoan & Nordlund theory matches our simulations with fair accuracy, the other theories either fail to reproduce the main qualitative outcome of the simulations or require some modifications. We conclude that turbulence plays a key role in shaping the IMF, with a shallower turbulence power spectrum producing a shallower high-mass IMF, and hence more massive stars.
The Gaia-ESO survey: 3D NLTE abundances in the open cluster NGC 2420 suggest atomic diffusion and turbulent mixing at the origin of chemical abundance variations
Acceleration of Energetic Particles through Reconnection of Weakly Stochastic Magnetic Field
天体物理介质是湍流的，因此重联应该在存在预先存在的湍流的情况下进行处理。我们考虑Lazarian & Vishniac（1999）的快速磁重联模型，该模型预言重联速率受湍流运动的强度和注入尺度的控制。我们提供了新的证据，成功的测试模型，并认为该模型提出了一个通用的设置为天体物理重联事件。我们研究粒子加速，发生在体积的驱动湍流以及湍流体积中存在的大规模重联。我们证明，在后一种情况下，加速度是一阶费米型，从而支持Gouveia dal Pino和Lazarian（2005）提出的加速度模型。
Galactic Dust Polarization in Turbulent Multiphase ISM: On the Origin of the $EE/BB$ Asymmetry
Institute for Advanced Study（高等研究院）；California Institute of Technology（加州理工学院）；Korea Astronomy and Space Science Institute（韩国天文学与宇宙学研究所）；Korea University of Science and Technology（韩国科学技术院）；Leiden Observatory, Leiden University（莱顿大学莱顿天文台）
Density distribution function of a self-gravitating isothermal compressible turbulent fluid in the context of Molecular Clouds ensembles II: the contribution of the turbulent term and the potential of the outer shells
