论文标题
低表面亮度星系的恒星质量和恒星质量比色关系
Stellar Mass and stellar Mass-to-light ratio-Color relations for Low Surface Brightness Galaxies
论文作者
论文摘要
我们通过将其多频谱分布（SED）拟合到恒星种群合成（SPS）模型来估计低表面亮度星系（LSBG）样品的恒星质量。派生的恒星质量（log m*/msun）从7.1到11.1，平均值为m*/msun = 8.5，低于正常星系。每个频段中的恒星质量与光比（M/L）的变化很小，但随着M*的增加而增加。 M* M/L的这种趋势在蓝色频段中甚至更强。另外，我们的LSBG的M/L从R频段略微下降到较长的波长频段。 LOG M/L_J（J = G，R，I和Z）与G-R和G-I的光学颜色相对紧密。与文献中的几种代表性的M/L色关系（MLCR）相比，我们基于LSBG数据的MLCR始终是先前在多种星系样本上定义的文献MLCR中，而MLCR之间的现有较小差异更大，并且在SED模型中的差异更大。光度零点也是，而不是将LSBG与汇丰银行区分开的星系表面亮度本身。如果考虑到这些主要成分，我们的LSBG很可能会遵循以前在不同星系种群上定义的代表性MLCR。
We estimate the stellar mass for a sample of low surface brightness galaxies (LSBGs) by fitting their multiband spectral energy distributions (SEDs) to the stellar population synthesis (SPS) model. The derived stellar masses (log M*/Msun) span from 7.1 to 11.1, with a mean of log M*/Msun=8.5, which is lower than that for normal galaxies. The stellar mass-to-light ratio (M/L) in each band varies little with absolute magnitude, but increases with higher M*. This trend of M/L with M* is even stronger in bluer bands. In addition, the M/L for our LSBGs slightly declines from the r band to the longer wavelength bands. The log M/L_j (j=g,r,i,and z) have relatively tight relations with optical colors of g-r and g-i. Compared with several representative M/L-color relations (MLCRs) from literature, our MLCRs based on LSBG data are consistently among those literature MLCRs previously defined on diverse galaxy samples, and the existing minor differences between the MLCRs are more caused by the differences in the SED model ingredients including initial mass function, star formation history, and stellar population model, and the line fitting techniques, galaxy samples, and photometric zero-point as well, rather than the galaxy surface brightness itself which distinguishes LSBGs from HSBGs. Our LSBGs would be very likely to follow those representative MLCRs previously defined on diverse galaxy populations, if those main ingredients were taken into account.
