论文标题
M 51-NGC 5195系统的空间分辨恒星种群性质来自多波长光度数据
Spatially-resolved Stellar Population Properties of the M 51-NGC 5195 System from Multi-wavelength Photometric Data
论文作者
论文摘要
我们使用M 51及其伴侣NGC 5195的多波段光度图像从紫外线到光学和红外线，我们研究了这种相互作用系统与恒星种群合成模型的空间分辨出的恒星种群特性。观察到的IRX用于限制尘埃灭绝。从模型拟合中也推断出恒星质量。通过将观察到的光谱分布（SED）与合成的光谱分布拟合，我们得出了恒星年龄，金属性，灰尘灭绝和恒星质量的二维分布。在M 51中，从凸起的两个宏伟设计的螺旋臂显示出年轻的年龄，丰富的金属性和丰富的灰尘。武器间区域充满了较旧的，贫困的金属和较少尘土飞扬的恒星种群。除了从M 51延伸到NGC 5195的螺旋臂外，NGC 5195的恒星人口特性是毫无疑问的。 NGC 5195比M 51大得多，其核心非常尘土，$ a_v $升至1.67 mag，并且在恒星的质量表面密度中致密。近距离接触可能会将M51螺旋臂的灰尘驱动到NGC 5195的中心。
Using multi-band photometric images of M 51 and its companion NGC 5195 from ultraviolet to optical and infrared, we investigate spatially resolved stellar population properties of this interacting system with stellar population synthesis models. The observed IRX is used to constrain dust extinction. Stellar mass is also inferred from the model fitting. By fitting observed spectral energy distributions (SEDs) with synthetical ones, we derive two-dimensional distributions of stellar age, metallicity, dust extinction, and stellar mass. In M 51, two grand-designed spiral arms extending from the bulge show young age, rich metallicity, and abundant dust. The inter-arm regions are filled with older, metal-poorer, and less dusty stellar populations. Except for the spiral arm extending from M 51 into NGC 5195, the stellar population properties of NGC 5195 are quite featureless. NGC 5195 is much older than M 51, and its core is very dusty with $A_V$ up to 1.67 mag and dense in stellar mass surface density. The close encounters might drive the dust in the spiral arm of M51 into the center of NGC 5195.
