论文标题
粉尘凝结和碎片崩溃的云芯及其对非理想磁流失动力学效应的影响
Dust coagulation and fragmentation in a collapsing cloud core and their influence on non-ideal magnetohydrodynamic effects
论文作者
论文摘要
我们确定云芯塌陷期间灰尘尺寸分布的时间演变，这既是灰尘凝结和灰尘碎片化，以研究灰尘生长对非理想磁性水力动力学效应的影响。崩溃核心的密度演化是由一个区域模型给出的。我们假设两种类型的灰尘模型：仅由硅酸盐（硅酸盐灰尘）和灰尘组成，表面由$ \ mathrm {h_ {2} o} $ ice（$ \ mathrm {h_ {2} o} $冰尘）组成。当仅考虑碰撞凝血时，对于硅酸盐和$ \ mathrm {h_ {2} o} $冰粉尘病例，非理想的磁水动力效应在高密度区域无效。这是因为粉尘凝血减少了小灰尘颗粒的丰度，从而导致电荷颗粒在灰尘表面上的效率较低。对于硅酸盐灰尘情况，当包括碰撞碎片化时，非理想的磁性水力动力学效应确实适用于$ n _ {\ mathrm {h}}> 10^{12} {12} \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ mathrm {cm^{ - 3}} $，因为丰富的小粉尘的生产。另一方面，对于$ \ mathrm {h_ {2} o} $冰尘的情况，由于碎片而产生的小灰尘颗粒的产生并不有效。因此，对于$ \ mathrm {h_ {2} o} $冰尘的情况，非理想的磁性水力动力学效应仅适用于$ n _ {\ mathrm {h}} \ gtrsim 10^{14} {14} {14} \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ m i {cm^cm^{cm^{cmm^{cmm^collis，甚至在collis的范围内。我们的结果表明，有必要考虑尘埃碰撞凝血和碎片化以激活非理想的磁性水动力效应，这应该在星和磁盘形成过程中起重要作用。
We determine the time evolution of the dust particle size distribution during the collapse of a cloud core, accounting for both dust coagulation and dust fragmentation, to investigate the influence of dust growth on non-ideal magnetohydrodynamic effects.The density evolution of the collapsing core is given by a one-zone model. We assume two types of dust model: dust composed only of silicate (silicate dust) and dust with a surface covered by $\mathrm{H_{2}O}$ ice ($\mathrm{H_{2}O}$ ice dust). When only considering collisional coagulation, the non-ideal magnetohydrodynamic effects are not effective in the high-density region for both the silicate and $\mathrm{H_{2}O}$ ice dust cases. This is because dust coagulation reduces the abundance of small dust particles, resulting in less efficient adsorption of charged particles on the dust surface. For the silicate dust case, when collisional fragmentation is included, the non-ideal magnetohydrodynamic effects do apply at a high density of $n_{\mathrm{H}}>10^{12} \ \mathrm{cm^{-3}}$ because of the abundant production of small dust particles. On the other hand, for the $\mathrm{H_{2}O}$ ice dust case, the production of small dust particles due to fragmentation is not efficient. Therefore, for the $\mathrm{H_{2}O}$ ice dust case, non-ideal magnetohydrodynamic effects apply only in the range $n_{\mathrm{H}}\gtrsim 10^{14} \ \mathrm{cm^{-3}}$, even when collisional fragmentation is considered. Our results suggest that it is necessary to consider both dust collisional coagulation and fragmentation to activate non-ideal magnetohydrodynamic effects, which should play a significant role in the star and disk formation processes.
