论文标题
温气对银河杆屈曲不稳定的影响
The effect of warm gas on the buckling instability in galactic bars
论文作者
论文摘要
通过使用$ n $ body和水电模拟，我们研究了星系中棒的形成和演变，其大量气体含量重点是屈曲不稳定性现象。星系最初由球形暗物质光环和恒星，恒星和气态组成，具有与银河系相似的参数，并以10 GYR的形式进化。我们考虑了气体分数的不同值$ f = 0-0.3 $，为了隔离气体的效果，我们通过不允许气体冷却并形成恒星来保持分数恒定。在具有较高气体级数的模拟中形成的恒星条较弱且较短，并且对于高于0.3的气体馏分根本不会形成。由于气体的初始扰动，气体分数为0.1的棒，但是尽管进化较长，但在进化结束时却没有比无碰撞情况的强度强。气体成分中的条较弱；它们达到了4 Gyr左右的最大强度，后来又降低到球体形状。屈曲不稳定性期间恒星棒的变形对于更高的气体部分而言较弱，并且杆的削弱较小，但是在径向剖面和面对面的投影方面，它的结构都具有相似的结构。对于$ f = 0.2，$第一个屈曲持续更长的时间，并且条不会发生次要屈曲事件，而对于$ f = 0.3，$不会发生屈曲。尽管存在这些差异，但所有条形都会在进化结束时在恒星和气体成分中产生箱形/花生的形状，尽管它们的厚度较小，对于较高的气体部分。
By using $N$-body and hydro simulations, we study the formation and evolution of bars in galaxies with significant gas content focusing on the phenomenon of the buckling instability. The galaxies are initially composed of a spherical dark matter halo and only stellar, or stellar and gaseous, disks with parameters that are similar to the Milky Way and are evolved for 10 Gyr. We consider different values of the gas fraction $f =0-0.3$ and in order to isolate the effect of the gas, we kept the fraction constant during the evolution by not allowing the gas to cool and form stars. The stellar bars that form in simulations with higher gas fractions are weaker and shorter, and they do not form at all for gas fractions that are higher than 0.3. The bar with a gas fraction of 0.1 forms sooner due to initial perturbations in the gas, but despite the longer evolution, it does not become stronger than the one in the collisionless case at the end of evolution. The bars in the gas component are weaker; they reach their maximum strength around 4 Gyr and later decline to transform into spheroidal shapes. The distortion of the stellar bar during the buckling instability is weaker for higher gas fractions and weakens the bar less significantly, but it has a similar structure both in terms of radial profiles and in face-on projections. For $f=0.2,$ the first buckling lasts significantly longer and the bar does not undergo the secondary buckling event, while for $f=0.3,$ the buckling does not occur. Despite these differences, all bars develop boxy/peanut shapes in the stellar and gas component by the end of the evolution, although their thickness is smaller for higher gas fractions.
