论文标题
早期宇宙中年轻的圆盘星系的碰撞
Collisions of young disc galaxies in the early universe
论文作者
论文摘要
在当地的宇宙中，圆盘星系通常是良好的发展且稳定的。他们与卫星星系的碰撞自然会产生环形结构，并已广泛研究并进行了广泛的研究。相反，在高红移时，圆盘星系仍在发育和块状。这些年轻的星系更频繁地相互作用。但是，他们的碰撞产物仍然难以捉摸。在这里，我们系统地研究了具有不同初始条件的轨道上的块状星系与卫星之间的小碰撞，并找到一种与局部碰撞环星系不同的新结构。目标星系的结块由Toomre参数的值（$ Q $）进行了微调。有趣的是，在目标银河系中没有任何中央核的迹象，形成了厚和打结的环结构。我们的结果提供了对最近在R5519中在RedShift $ z = 2.19 $的空圈星系的有希望的解释。此外，我们表明，与已广泛研究的孤立自我发展的块状星系相比，相撞星系的块状状态存在时间更长的时间尺度。
In the local universe, disc galaxies are generally well evolved and Toomre stable. Their collisions with satellite galaxies naturally produce ring structures, which has been observed and extensively studied. In contrast, at high redshifts, disc galaxies are still developing and clumpy. These young galaxies interact with each other more frequently. However, the products of their collisions remain elusive. Here we systematically study the minor collisions between a clumpy galaxy and a satellite on orbits with different initial conditions, and find a new structure that is different from the local collisional ring galaxies. The clumpness of the target galaxy is fine-tuned by the values of Toomre parameter, $Q$. Interestingly, a thick and knotty ring structure is formed without any sign of a central nucleus in the target galaxy. Our results provide a promising explanation of the empty ring galaxy recently observed in R5519 at redshift $z=2.19$. Moreover, we show that the clumpy state of the collided galaxy exists for a much longer timescale, compared to isolated self-evolved clumpy galaxies that have been widely investigated.
