论文标题
与M17复合物相关的无线电Quiet HII区域中的新大规模接触双二进制
New Massive Contact Twin Binary in a Radio-quiet HII Region Associated with the M17 Complex
论文作者
论文摘要
早期B恒星可能会创建一个以射电压为单位的HII区域。我们报告了M17综合体中与Radio-Quiet HII区域G014.645--00.606相关的新的早期B恒星的鉴定。比率Quiet HII地区G014.645--00.606与三个放射优惠的HII地区候选人相邻。鉴于Magpis 20 cm调查的敏感性约为1-2 MJY，预计无线电Quiet HII区域的电离来源预计将晚于B1V。如果它们的Gaia EDR3的视差与同一区域内的22 GHz H $ _2 $ o Maser源相匹配，则首先选择了星星。我们使用了由ZTF光度计目录制成的颜色刻度图来选择大型恒星的候选物，因为固有的$ G-R $颜色的巨大恒星的颜色从B型变为O型星星很少变化。五颗星位于颜色刻度图的区域中，通常发现较低的巨星或进化的较低肿块后序列星星。来源1、2和3中的三颗星中有三个位于三个IR气泡的空腔中，并在三个IR气泡周围检测到延长的H $α$发射。我们建议来源1、2和3是与Radio-Quiet地区G014.645---00.606相关的早期B恒星的候选者。特别是，Source 1是EW类型的二进制EW类型，短期为0.825天，而Source 2是EA类型的EA类型，以0.919天的短期黯然失色。两个二进制系统的物理参数是通过Phoebe模型得出的。源1是两颗恒星的双二个二进制，带有T〜23,500 K，源2包含一个更热的成分（T〜20,100 K），一个较冷的组件（T〜15,500 K）。来源1的$ o-c $值显示出下降的趋势，这意味着来源的时期正在变形。来源1可能是接触早期双二元二进制的接触，为此，传质可能会导致其轨道收缩。
Early-B stars may create an HII region that appears as radio-quiet. We report the identification of new early-B stars associated with the radio-quiet HII region G014.645--00.606 in the M17 complex. The ratio-quiet HII region G014.645--00.606 is adjacent to three radio-quiet WISE HII region candidates. The ionizing sources of the radio-quiet HII regions are expected to later than B1V, given the sensitivity about 1-2 mJy of the MAGPIS 20 cm survey. The stars were first selected if their parallaxes of GAIA EDR3 match that of the 22 GHz H$_2$O maser source within the same region. We used the color-magnitude diagram made from the ZTF photometric catalog to select the candidates for massive stars because the intrinsic $g-r$ colors of massive stars change little from B-type to O-type stars. Five stars lie in the areas of the color-magnitude diagram where either reddened massive stars or evolved post-main sequence stars of lower masses are commonly found. Three of the five stars, sources 1, 2, and 3, are located at the cavities of the three IR bubbles, and extended H$α$ emission is detected around the three IR bubbles. We suggest that sources 1, 2, and 3 are candidates for early-B stars associated with the radio-quiet region G014.645--00.606. Particularly, source 1 is an EW type eclipsing binary with a short period of 0.825 day, while source 2 is an EA type eclipsing binary with a short period of 0.919 day. The physical parameters of the two binary systems have been derived through the PHOEBE model. Source 1 is a twin binary of two stars with T~23,500 K, and source 2 contains a hotter component (T~20,100 K) and a cooler one (T~15,500 K). The $O-C$ values of source 1 show a trend of decline, implying that the period of the source is deceasing. Source 1 is likely a contacting early-B twin binary, for which mass transfer might cause its orbit to shrink.
