论文标题
热伽玛多拉德斯和A-F杂种开普勒候选者的光谱靠近三角洲Scuti不稳定带的热边界
Spectroscopy of hot Gamma Doradus and A-F hybrid Kepler candidates close to the hot border of the Delta Scuti instability strip
论文作者
论文摘要
如果伽马型脉冲是由对流阻断机制驱动的，则必须在足够深度处的对流包膜。有几个热伽玛DOR和杂种恒星候选者，其中不应有足够的对流范围来激发γdor型振荡。这些热对象的存在需要解释。因此，我们选择，观察并研究了24个热γdor和杂种候选者以研究其特性。使用安装在北端望远镜上的FIES仪器采集的中分辨率（r = 46 000）光谱获得了候选者的大气参数，化学丰度和VSINI值。我们还对keplerlong和短期数据进行了频率分析，以确定精确的脉动含量。我们在样本中只发现了五个真正的热γdor和三个真正的热杂种恒星。发现其他16颗恒星被发现为苯基γ多，ΔSCT或杂交变量。在真正的热γ多和杂交星的光谱中未检测到化学特征。我们研究了旋转和脉动模式之间的相互作用。我们还发现，与主序列A-F恒星相比，热γdor恒星的射抗抗蛋白含量和更大的半径。
If Gamma Dor-type pulsations are driven by the convective blocking mechanism, a convective envelope at a sufficient depth is essential. There are several hot Gamma Dor and hybrid star candidates in which there should not be an adequate convective envelope to excite theγDor-type oscillations. The existence of these hot objects needs an explanation. Therefore, we selected, observed and studied 24 hotγDor and hybrid candidates to investigate their properties. The atmospheric parameters, chemical abundances and vsini values of the candidates were obtained using medium-resolution (R= 46 000)spectra taken with the FIES instrument mounted at the NordicOptical Telescope. We also carried out frequency analyses of theKeplerlong- and short-cadence data to determine the exact pulsation contents. We found only five bona-fide hotγDor and three bona-fide hot hybrid stars in our sample. The other 16 stars were found to benormalγDor,δSct, or hybrid variables. No chemical peculiarity was detected in the spectra of the bona-fide hotγDor and hybrid stars. We investigated the interplay between rotation and pulsational modes. We also found that the hotγDor stars havehigherGaialuminosities and larger radii compared to main-sequence A-F stars.
