论文标题
银河系的同时j-，h-，k - 和l波段光谱观察结果。 I. IR Atlas
Simultaneous J-, H-, K- and L-band spectroscopic observations of galactic Be stars. I. IR atlas
论文作者
论文摘要
已经接受的是，恒星被折叠信封包围，这些信封与开普勒旋转中的圆盘几何形状大多兼容。我们的目标是对恒星的折叠环境的性质进行更完整的表征，该特性有助于限制现象的理论模型。我们提供了带有不同光谱亚型和亮度类别的银河样品的近红外，中分辨率的光谱。我们测量来自Paschen，Brackett，Pfund和Humphreys系列的氢重组线的不同参数，并利用它们在偶尔环境中诊断身体状况。我们分析了Br $α$和BR $γ$线和不同图表的不相同宽度（EW）比率。我们还鉴定了我，c i，n i，o i，na i，mg i，mg i，mg ii，si i，fe I和fe II的线条。分析特定于I，Mg II，Fe I，Fe II和O I系的EW测量值，我们发现它们与某些线路相关，与恒星的光谱类型相关。特别是，O i〜 $λ\，1.3168 \，μ$ m线的发射降低了后来的光谱类型。我们提出了一个22个恒星的地图集，涵盖了带有准平台观察的宽红外（IR）光谱范围。从详细的分析中，我们根据他们的不透明度定义了新的互补标准，即Mennickent对Be Stars的分类。我们样品中的某些物体存在紧凑的厚厚的信封，而在其他物体中，信封延伸且光学上很薄。最大宽度（FWHM）的完整宽度与峰分离（$δ\ Mathrm {V} $）与$ v \，\ sin \，br10，br $Δ$和HU14行的I $之间的相关性显示宽广的机制是旋转的。 LY $β$荧光是解释Mg II和O I线发射强度的关键机制。
It is already accepted that Be stars are surrounded by circumstellar envelopes, which are mostly compatible with a disc geometry in Keplerian rotation. We aim to obtain a more complete characterisation of the properties of the circumstellar environment of Be stars that helps to constrain the theoretical models of the Be phenomenon. We present near-infrared, medium-resolution spectra of a sample of galactic Be stars with different spectral subtypes and luminosity classes. We measure different parameters of the hydrogen recombination lines from the Paschen, Brackett, Pfund, and Humphreys series, and use them to diagnose physical conditions in the circumstellar environment. We analysed the equivalent-width (EW) ratio between Br$α$ and Br$γ$ lines and different diagrams of flux ratios. We also identify lines from He I, C I, N I, O I, Na I, Mg I, Mg II, Si I, Fe I, and Fe II. Analysing the EW measurements of particular He I, Mg II, Fe I, Fe II and O I lines, we find that for some lines they correlate with the spectral type of the star. Particularly, the emission of the O I~$λ\,1.3168\,μ$m line decreases towards the later spectral types. We present an atlas of 22 Be stars, that covers a wide infrared (IR) spectral range with quasi-simultaneous observations. From a detailed analysis, we define new complementary criteria to Mennickent's classification of Be stars according to their disc opacity. Some objects in our sample present compact thick envelopes, while in others the envelope is extended and optically thin. The correlation between the full widths at half maximum (FWHM) and the peak separation ($Δ\mathrm{V}$) versus $V\,\sin\,i$ for the Br10, Br$δ$, and Hu14 lines reveals that the broadening mechanism is rotational. The Ly$β$ fluorescence is a key mechanism to explain the intensity of the emission of Mg II and O I lines.
