论文标题
LSB星系中的异常恒星种群
Anomalous Stellar Populations in LSB Galaxies
论文作者
论文摘要
我们提出了两个LSB星系中CMD的HST WFC3近IIR观察结果，即F575-3和F615-1，这是因为由于缺乏H $α$排放而没有目前的恒星形成。近IIR CMD的关键特征已解决，例如红色巨型分支（RGB），渐近巨型分支（AGB）区域和蓝色主序列（BMS）的顶部。 F575-3在文献中具有任何CMD的最蓝RGB，表明平均金属性极低。 F615-1具有异常较宽的RGB和AGB序列，表明金属贫气气体（可能是输入材料）的恒星形成多个发作。与典型的AGB恒星相比，这两个星系都有不寻常的恒星群体到RGB的红色和亮度较低。这些恒星具有正常的光学色，但近红外颜色异常。我们建议，由于周围的热气盘，恒星种群可能类似于当地奇特的恒星，例如恒星，近红外过量。
We present new HST WFC3 near-IR observations of the CMD's in two LSB galaxies, F575-3 and F615-1, notable for having no current star formation based on a lack of H$α$ emission. Key features of the near-IR CMD's are resolved, such as the red giant branch (RGB), the asymptotic giant branch (AGB) region and the top of the blue main sequence (bMS). F575-3 has the bluest RGB of any CMD in the literature, indicating an extremely low mean metallicity. F615-1 has unusually wide RGB and AGB sequences suggesting multiple episodes of star formation from metal-poor gas, possibly infalling material. Both galaxies have an unusual population of stars to the red of the RGB and lower in luminosity than typical AGB stars. These stars have normal optical colors but abnormal near-IR colors. We suggest that this population of stars might be analogous to local peculiar stars like Be stars with strong near-IR excesses owing to a surrounding disk of hot gas.
