多波段二维面亮度测光分解对盘星系核球的研究  

2-D multi-band SBD photometric decomposition for NGC 0198

作　　者：王娇娇 孙艳春[1] WANG Jiaojiao;SUN Yanchun(Department of Astronomy,Beijing Normal University,100875,Beijing,China)

机构地区：[1]北京师范大学天文系,北京100875

出　　处：《北京师范大学学报（自然科学版）》2018年第4期467-471,共5页Journal of Beijing Normal University(Natural Science)

基　　金：中国科学院天文联合基金资助项目(10778717);中央高校基本科研业务费专项资金资助项目

摘　　要：研究核球的内禀形状是限制星系的形成与演化理论的重要方法之一,能够给出星系的形成与演化过程究竟是等级式并合的快过程还是长期内部活动形成伪核球的慢过程的重要线索.而慢过程的研究限于高分辨率的图像资料的缺乏,近十几年才得以展开,大多是在某一个波段进行的.选取了9个正视无棒旋涡星系在4或5个波段上分别对它们进行了二维面亮度测光分解,得到核球和盘在各个波段上的形态参数,在不同波段和不同星系类型之间进行了对比研究,结果表明:同一星系不同波段得到的参数有一定的离散,这可能与恒星宽泛的年龄范围有关;测光分解显示9个样本中5个包含经典核球、4个包含伪核球,并且伪核球全部位于晚型星系中,给出了对慢演化理论的重要验证;研究肯定了n=2作为经典核球和伪核球分界的合理性.另外,通过对比此前几乎单一波段的研究,发现伪核球可能不像以前认为的那么类似盘,经典核球也不像以前认为的那么类似椭圆星系.A good way to constrain the theory of formation and evolution of galaxies is to study intrinsic shape of bulges.This can reveal clues about whether the formation and evolution of galaxies are fast processes of hierarchical clustering,or rather secular internal processes by which pseudobulges are formed.Research on secular evolution developed only in recent decades due to lack of high resolution images and is often performed at single band.Our work with multi-band two-dimensional photometric decomposition for 9 face-on unbarred spiral galaxies obtains morphological parameters of bulges and disks,reveals differences and correlations between different image bands and galaxy classifications.These data indicate that parameters between multiple bands of the same galaxy are different,possibly due to wide ranging star ages.Five classical bulges and 4 pseudobulges are found in our samples.All pseudobulges belong to late disk galaxy,a significant verification of the theory of secular evolution.Criterion for applying n〈2 to separate pseudobulges from classical bulges is reasonable.Comparison with photometric decomposition in early times mainly at one band suggests that pseudobulges and classical bulges may not always resemble disk and elliptical galaxies as used to think before.

关 键 词：NGC 0198 伪核球 二维 测光分解 多波段 

分 类 号：P157.9[天文地球—天文学]