CAJ | 학술논문

旋涡星系的颜色梯度反映了其星族构成沿径向的分布,包含了星系恒星形成历史的信息.因此,对旋涡星系颜色梯度的研究有助于理解星系的形成和演化过程.大部分旋涡星系存在负的颜色梯度,其主要原因是旋涡星系存在星族梯度.颜色梯度与星系的面亮度之间存在内禀的相关,表明质量面密度在星系的形成和演化过程中具有重要作用.
선와성계적안색제도반영료기성족구성연경향적분포,포함료성계항성형성역사적신식.인차,대선와성계안색제도적연구유조우리해성계적형성화연화과정.대부분선와성계존재부적안색제도,기주요원인시선와성계존재성족제도.안색제도여성계적면량도지간존재내품적상관,표명질량면밀도재성계적형성화연화과정중구유중요작용.
The color gradient of spiral galaxy freezes its fossil information of the star formation history along the disk and therefore provides a strong constraint on the models of disk formation and evolution. In this paper we review the recent progress of the research on color gradients of spiral galaxies, including the observational results, the explanation of color gradients and the evolvement of the color gradients. In addition, we list the observational factors which influence the measurement of color gradients.Most of spiral galaxies show negative color gradients, i.e. the color is gradually bluer outwards. Either the bulge or disk components of spiral galaxies has negative color gradient. The color gradients of disk components are independent of the concentration parameter, which implies that the bulge may not strongly affect the formation and evolution of the disk component. There is also no significant correlation between disk color gradients and the size of galaxies, but bigger galaxies tend to have smaller scatters of the color gradients. The color gradients are weakly dependent on the absolute magnitude, this weak correlation suggests that the stellar mass may not be an important ingredient in regulating the inside-out growth of galactic disk. There is an intrinsic correlation between the color gradients and surface brightness, with lower surface brightness galaxies having steeper color gradients. This result indicates the mass surface density may play an important role in the formation and evolution of galactic disk, which gives a strong observational constraint on the model.The color gradients of spiral galaxies were found to be mainly caused by stellar population gradients, with inner region having higher metallicity and older stellar population than the outer part. The dust extinction only plays a minor role in regulating the color gradients of spiral galaxies.