论文标题
丝体内的积聚驱动的湍流II:自我重力的影响
Accretion driven turbulence in filaments II: Effects of self-gravity
论文作者
论文摘要
我们通过包括自我实现并研究核心形成和崩溃的影响,扩展了与代码公羊有关积聚驱动的湍流的模拟的工作。我们表明,径向积聚到细丝上会驱动不是各向同性但径向占主导地位的湍流运动。与没有重力的细丝相反,自我散发细丝的速度分散在平衡中不会沉降。尽管显示出相似的驱动湍流,但它们仍会不断消散其速度分散,直到核心形成开始。该差异与半径的演变有关,因为它决定了耗散率。在非严格案例中,细丝生长不受限制,其半径随时间线性增长。相比之下,自我杀菌案例中最大程度的范围导致耗散率提高。此外,吸积驱动的湍流显示出径向曲线,该轮廓与密度抗相关。这会导致整个细丝中恒定的湍流压力。由于额外的湍流压力没有径向梯度,因此不会导致细丝的稳定性,也不会增加临界线质量。但是,这种径向湍流确实会影响细丝的半径,从而增加了程度并设置其最大值。此外,半径的演化还会影响核心的生长时间尺度,这与积聚细丝的崩溃时间范围相比,核心形成核心形成到高线质量。
We extend our previous work on simulations with the code RAMSES on accretion driven turbulence by including self-gravity and study the effects of core formation and collapse. We show that radial accretion onto filaments drives turbulent motions which are not isotropic but radially dominated. In contrast to filaments without gravity, the velocity dispersion of self-gravitating filaments does not settle in an equilibrium. Despite showing similar amounts of driven turbulence, they continually dissipate their velocity dispersion until the onset of core formation. This difference is connected to the evolution of the radius as it determines the dissipation rate. In the non-gravitational case filament growth is not limited and its radius grows linearly with time. In contrast, there is a maximum extent in the self-gravitational case resulting in an increased dissipation rate. Furthermore, accretion driven turbulence shows a radial profile which is anti-correlated with density. This leads to a constant turbulent pressure throughout the filament. As the additional turbulent pressure does not have a radial gradient it does not contribute to the stability of filaments and does not increase the critical line-mass. However, this radial turbulence does affect the radius of a filament, adding to the extent and setting its maximum value. Moreover, the radius evolution also affects the growth timescale of cores which compared to the timescale of collapse of an accreting filament limits core formation to high line-masses.