论文标题
螺旋磁盘的最新形成托管祖先球状簇位于珀尔修斯最亮星系中心的球状簇:I。螺旋盘
Recent Formation of a Spiral Disk Hosting Progenitor Globular Clusters at the center of the Perseus Brightest Cluster Galaxy: I. Spiral Disk
论文作者
论文摘要
我们在NGC 1275的中心(在Perseus群集中心的巨型椭圆形星系中心)介绍了螺旋盘的性质和起源,该圆盘的半径覆盖了$ \ sim $$ 5 \,\ rm kpc $的半径。通过比较单恒星种群中长缝光谱中测量的恒星吸收线与合成光谱,我们发现这些线的拟合需要两个恒星种群:(i)一个非常年轻的人群在径向速度达到$ \ pm \ pm 250 {\ rm \,km \,km \,km \ rm \ rm \ rm \ rm, $ \ sim $$ 720 \,\ rm pc $ of nucleus的PC $,$ 1 \,σ$速度分散剂明显低于$ 140 {\ rm \,km \,km \,s^{ - 1}} $,年龄为$ 0.15 \ pm pm 0.05 \ pm 0.05 \ rm \ rm \ rm \,gyr $; (ii)一个非常古老的人群具有恒定的径向速度,半径与系统速度相对应,$ \ sim $$ 250 {\ rm \,km \,km \,s^{ - 1}} $的速度分散率更高,大约$ 10 \,\ 10 \,\ rm gyr $。我们将前者归因于与螺旋磁盘相关的盛大后种群,而后者则沿同一视线沿着NGC 1275的主要恒星体。如果螺旋盘是食人星系的残留物,则其祖细胞将不得不在面对密集的Ram压力剥离的情况下保留大量的气体,以形成$ \ sim 3 \ sim 3 \ sim times 10^9 \的恒星中的总质量,m_ \ odot $。更有可能的中央螺旋最初由一个气体体组成,从残留的冷却流中积聚在遥远的过去,然后体验了starburst $ \ sim $ \ sim $$ 0.15 \,\ rm gy $ ogo以形成其出色的身体。
We address the nature and origin of a spiral disk at the center of NGC 1275, the giant elliptical galaxy at the center of the Perseus cluster, that spans a radius of $\sim$$5\,\rm kpc$. By comparing stellar absorption lines measured in long-slit optical spectra with synthetic spectra for single stellar populations, we find that fitting of these lines requires two stellar populations: (i) a very young population that peaks in radial velocity at $\pm 250 {\rm \, km \, s^{-1}}$ of the systemic velocity within a radius of $\sim$$720\,\rm pc$ of the nucleus, a $1\,σ$ velocity dispersion significantly lower than $140 {\rm \, km \, s^{-1}}$, and an age of $0.15 \pm 0.05 \rm\,Gyr$; and (ii) a very old population having a constant radial velocity with a radius corresponding to the systemic velocity, a much broader velocity dispersion of $\sim$$250 {\rm \, km \, s^{-1}}$, and an age of around $10\,\rm Gyr$. We attribute the former to a post-starburst population associated with the spiral disk, and the latter to the main stellar body of NGC 1275 along the same sight line. If the spiral disk is the remnant of a cannibalized galaxy, then its progenitor would have had to retain an enormous amount of gas in the face of intensive ram-pressure stripping so as to form a total initial mass in stars of $\sim 3 \times 10^9 \,M_\odot$. More likely, the central spiral originally comprised a gaseous body accreted over the distant past from a residual cooling flow, before experiencing a starburst $\sim$$0.15\,\rm Gyr$ ago to form its stellar body.