论文标题
探测红色团块巨人之间的红外过量连接与LI的增强
Probing infrared excess connection with Li enhancement among red clump giants
论文作者
论文摘要
我们已经在低质量红色巨头进行了搜索，以寻找合并情景的证据，以触发He-Flash和随后的LI增强。我们从galah调查中选择了一个带有李的li丰度的红色巨人样本，分别从2个质量和明智的调查中选择了近和中期通量。该样品包含418个凉爽的红色团块巨人和359个上部红色巨人分支巨头。大多数巨人和大多数超级富裕的巨人都没有表现出多余的巨人。只有五个红色团块巨人和一名RGB巨人表现出多余的IR。值得注意的是，在IR多余的五个红色团块巨头中，有三个是超级li-rich（a（li）> = 3.2 dex），而两个则是li-liich（a（li）> = 1.0 dex）。结果表明，在红色团块巨头之间的LI增强可能是由于两个通道造成的：一个是由单星进化中的原位He-flash引起的，另一个是由于He-White矮人与巨型矮人与巨人Heert core触发的事件所触发的。在后一种情况下，合并事件预计，由于质量损失，红外过剩。我们使用尘土飞扬的代码和衍生的灰尘参数对所有六个巨人的IR过量建模。估计的运动阶段的粉尘信封的估计运动年龄和时间尺度表明，LI的增强是最近发生的。此外，与没有IR超过的Li-Normal和Li-Formal and-Formal和Li-Form的巨人相比，分析显示了快速旋转器（VSINI> = 8 km/s）的快速旋转器（Vsini> = 8 km/s）的比例明显更高，与没有IR超过的Li-Normal和Li-Normal和Li-formal和Li-Formal Beads相比。
We have performed a search among low mass red giants for finding evidence for merger scenario for triggering He-flash and subsequent Li enhancement. We chose a sample of red giants from GALAH survey with well-measured Li abundances, and near and mid-IR fluxes from 2MASS and WISE surveys, respectively. The sample contains 418 cool red clump giants and 359 upper red giant branch giants. Most of the giants and majority of super Li-rich giants show no IR excess. Only five red clump giants and one RGB giant show IR excess. Notably, of the five red clump giants with IR excess, three are super Li-rich (A(Li) > = 3.2 dex), and two are Li-rich (A(Li) > = 1.0 dex). Results suggest Li enhancement among red clump giants may be due to two channels: one resulting from in-situ He-flash in single star evolution and the other due to He-flash triggered by events like merger of He-white dwarfs with giants He-inert core on RGB. In the latter case, IR excess, as a result of mass loss, is expected from merger events. We have modelled IR excess in all six giants using DUSTY code and derived dust parameters. The estimated kinematic ages and time scales of dust envelopes of the super Li-rich phase suggest Li enhancement took place very recently. Further, the analysis shows a significantly higher proportion (four out of five red clump giants) of rapid rotators (vsini > = 8 km/s) among Li-rich giants with IR excess compared to Li-normal and Li-rich giants with no IR excess.
