论文标题
群集中早期星系的径向独立尺寸生长的证据
Evidence for radially independent size growth of early-type galaxies in clusters
论文作者
论文摘要
在所有半径上，早期型星系星系的生长是内外，外部还是以相同的速度进行，尚不清楚早期型聚类星系的生长。在这项工作中，我们测量了由半径（包括80 \％的星系光）的半径定义的星系尺寸，非参数。我们还确定了星系光浓度的非参数估计，该估计测量了银河郊区表面亮度曲线的曲率。我们使用了由$ \ log m/m _ {\ odot} \ ga 10.7 $跨越$ 0.17 <z <z <1.81美元的群集中的128个形态上的早期类型星系中的质量限制样品的几乎随机抽样。从这些数据中，我们得出了尺寸质量和浓度质量关系及其演变。在80 \％的轻度半径下，簇中的早期型星系大约是所有红移时50 \％半径的2.7倍，并且在过去10个GYR中接近de vaucouleurs概况。虽然$ z = 2 $和$ z = 0 $半光和80 \％\％的光尺寸增加了$ 1.7 $，但集中度在$ 2 $ \％之内保持恒定，也就是说，在群集环境中早期型星系的大小增长在同一速度下以同一速度进行。文献中提出的现有物理解释与我们的结果不一致，这表明需要专门的数值模拟来确定影响星系结构的物理机制。
It is not well understood whether the growth of early-type cluster galaxies proceeds inside-out, outside-in, or at the same pace at all radii. In this work we measured the galaxy size, defined by the radius including 80\% of the galaxy light, non-parametrically. We also determined a non-parametric estimate of galaxy light concentration, which measures the curvature of the surface brightness profile in the galaxy outskirts. We used an almost random sampling of a mass-limited sample formed by 128 morphologically early-type galaxies in clusters with $\log M/M_{\odot} \ga 10.7$ spanning the wide range $0.17<z<1.81$. From these data we derived the size-mass and concentration-mass relations, as well as their evolution. At 80\% light radius, early-type galaxies in clusters are about 2.7 times larger than at 50\% radius at all redshifts, and close to de Vaucouleurs profiles in the last 10 Gyr. While between $z=2$ and $z=0$ both half-light and 80\% light sizes increase by a factor of $1.7$, concentration stays constant within $2$\%, that is to say the size growth of early-type galaxies in cluster environments proceeds at the same pace at both radii. Existing physical explanations proposed in the literature are inconsistent with our results, demonstrating the need for dedicated numerical simulations to identify the physical mechanism affecting the galaxy structure.
