标题： 基本平面散射对星系年龄的依赖性 显示英文标题

标题： Dependence of the Fundamental Plane Scatter on Galaxy Age

摘要： 基本平面（FP）具有固有散射，这不能仅由观测误差来解释。 使用最近获得的附近早型星系的年龄估计，我们表明星系相对于FP的位置取决于其年龄。 特别是，平均FP对应于年龄约为10 Gyr的椭圆星系。 较年轻的星系相对于平均关系显得更亮，表面亮度更高。 古老的椭圆星系形成了FP的“上包络线”。 对于我们的大部分非星系团星系样本，年龄可以解释B波段FP中几乎一半的散射。 如果样本的平均年龄随红移变化，基于FP的距离测定可能会有系统偏差。 我们还表明，基本平面残差、B-V颜色和Mg_2线强度与叠加在古老恒星种群上的年龄增长中心爆发是一致的。 这加强了这样的观点，即这些年龄估计是在追踪由气体合并事件引发的最后一次主要恒星形成时期。 我们简要讨论了合并残余物和年轻椭圆星系在关键观测参数方面的经验“演化轨迹”。 显示英文摘要

摘要： The fundamental plane (FP) has an intrinsic scatter that can not be explained purely by observational errors. Using recently available age estimates for nearby early type galaxies, we show that a galaxy's position relative to the FP depends on its age. In particular, the mean FP corresponds to ellipticals with an age of ~10 Gyr. Younger galaxies are systematically brighter with higher surface brightness relative to the mean relation. Old ellipticals form an `upper envelope' to the FP. For our sample of mostly non-cluster galaxies, age can account for almost half of the scatter in the B band FP. Distance determinations based on the FP may have a systematic bias, if the mean age of the sample varies with redshift. We also show that fundamental plane residuals, B-V colors and Mg_2 line strength are consistent with an ageing central burst superposed on an old stellar population. This reinforces the view that these age estimates are tracing the last major episode of star formation induced by a gaseous merger event. We briefly discuss the empirical `evolutionary tracks' of merger-remnants and young ellipticals in terms of their key observational parameters.