论文标题
早期型星系同伴星系的动力学
Dynamics of Companion Galaxies of Early-Type Galaxies
论文作者
论文摘要
我们通过分析这些ETG的卫星和同伴星系的动力学来估算115个早期型星系（ETG）的动力质量。我们从$ k_s $ band中的$ k_s $ band中选择了从余然后距离数据库（EDD）中的$ k_s $ band中的绝对幅度的星系。我们还选择了216个螺旋星系进行比较。我们采用了一个简单的模型来模拟各个距离的卫星星系中观察到的动力质量。我们的模拟表明，从具有椭圆形轨道的卫星星系中得出的动态质量也小于具有圆形轨道的卫星星系，即使它们包含相同的深质量光环。因此，观察到的$ m_ \ mathrm {dyn}/m_ \ mathrm {b} $分布与距离之间的关系取决于轨道形状。从我们观察到的$ m_ \ mathrm {dyn}/m_ \ mathrm {b} $分布和距离之间的关系中，我们建议ETG的卫星星系具有相对椭圆形的轨道，比螺旋星系具有比$ M_ \ Mathrm {dyn}/m _ g} $ {星系。
We estimated the dynamical masses of 115 early-type galaxies (ETGs) by analyzing the dynamics of satellite and companion galaxies of these ETGs. We selected galaxies with absolute magnitudes between -22 and -25 in the $K_s$-band from the Extragalactic Distance Database (EDD). We also selected 216 spiral galaxies for comparison. We employed a simple model to simulate the observed dynamical mass from satellite galaxies at various distances. Our simulations showed that the dynamical masses derived from satellite galaxies with elliptical orbits would be smaller than those with circular orbits even they contain the same dark mass halos. Therefore, relationships between the observed $M_\mathrm{dyn}/M_\mathrm{b}$ distributions and distances would depend on orbital shapes. From the relationships between our observed $M_\mathrm{dyn}/M_\mathrm{b}$ distributions and distances, we suggest that the satellite galaxies of the ETGs have relatively more elliptical orbits than those of the spiral galaxies have and the $M_\mathrm{dyn}/M_\mathrm{b}$ of the ETGs are greater than that of the spiral galaxies.
