标题： 近于正面的低表面亮度盘状星系的多波长研究 显示英文标题

标题： Multiwavelength study of nearly face-on low surface brightness disk galaxies

摘要： 我们利用恒星人口综合（EPS）模型PEGASE（具有指数衰减的恒星形成率）来拟合1802个几乎正面盘状低表面亮度星系（LSBG）的多波段光谱能量分布（SED），从而研究它们的年龄。无论采用恒定还是变化的尘埃消光，这些LSBG的推导年龄大多在1到5吉年之间，这与之前大多数针对较小样本的研究结果相似。这意味着这些LSBG在其最近期形成了大部分恒星。然而，约2-3%的小部分样本显示出更大的年龄，约为5到8吉年，表明它们的主要恒星形成过程可能更早发生。同时，用相同方法选取并研究了5886个高表面亮度星系（HSBG）样本以作对比。同样地，对于大多数样本（97%），推导出的年龄也是1到5吉年。这可能意味着这些LSBG与它们对应的HSBG在恒星形成历史方面没有太大的差异。但需要注意的是，HSBG通常比LSBG年轻约0.2吉年，这可能表明HSBG的恒星形成活动比LSBG更为近期。 显示英文摘要

摘要： We study the ages of a large sample (1,802) of nearly face-on disk low surface brightness galaxies (LSBGs) by using the evolutionary population synthesis (EPS) model PEGASE with exponential decreasing star formation rate to fit their multiwavelength spectral energy distributions (SEDs) from far-ultraviolet (FUV) to near-infrared (NIR). The derived ages of LSBGs are 1-5 Gyr for most of the sample no matter the constant or varying dust extinction is adopted, which are similar to most of the previous studies on smaller samples. This means that these LSBGs formed their majority of stars quite recently. However, a small part of the sample (~2-3%) have larger ages as 5-8 Gyr, meaning their major star forming process may occur earlier. At the same time, a large sample (5,886) of high surface brightness galaxies (HSBGs) are selected and studied in the same method for comparisons. The derived ages are 1-5 Gyr for most of the sample (97%) as well. These may mean that probably these LSBGs have no much different star formation history from their HSBGs counterparts. But we should notice that the HSBGs are about 0.2 Gyr younger generally, which could mean that the HSBGs may have more recent star forming activities than the LSBGs.