论文标题
用索非亚/EXES检测R Leonis中二氧化碳的红外荧光
Detection of infrared fluorescence of carbon dioxide in R Leonis with SOFIA/EXES
论文作者
论文摘要
我们报告了基于高光谱分辨率的观测值的高光谱分辨率观测值12.8-14.3 UM在红外线 - echelle光谱仪（EXES）上进行的高光谱分辨率观察结果报告，该二氧化碳的检测。我们在几个振动带中发现了约240个CO2发射线。由于多普勒的偏移偏移，这些检测是可能的，这使我们能够避免受到Telluric CO2功能的污染。最高的激发线涉及约7000 K的能量。检测到的线狭窄（平均反vlovelvovel宽度〜2.5 km/s）和弱（通常<10％的连续体）。 RO振动图显示，有三种不同的人群，温暖，热和非常热，旋转温度分别为〜550、1150和1600 K。从该图中，我们得出了〜2.2e+16 cm^{ - 2}的柱密度的下限。基于R Leo包膜模型的进一步计算表明，总的柱密度可以大至7.0e+17 cm^{ - 2}，并且相对于H2〜2.5e-05。检测到的线可能是由于高能振动状态的二氧化碳分子脱落而形成的，高能振动状态基本上由2.7和4.2 um的强r leo连续体填充。
We report on the detection of hot CO2 in the O-rich AGB star R Leo based on high spectral resolution observations in the range 12.8-14.3 um carried out with the Echelon-cross-Echelle Spectrograph (EXES) mounted on the Stratospheric Observatory for Infrared Astronomy (SOFIA). We have found ~240 CO2 emission lines in several vibrational bands. These detections were possible thanks to a favorable Doppler shift that allowed us to avoid contamination by telluric CO2 features. The highest excitation lines involve levels at an energy of ~7000 K. The detected lines are narrow (average deconvolved width ~2.5 km/s) and weak (usually <10% the continuum). A ro-vibrational diagram shows that there are three different populations, warm, hot, and very hot, with rotational temperatures of ~550, 1150, and 1600 K, respectively. From this diagram, we derive a lower limit for the column density of ~2.2E+16 cm^{-2}. Further calculations based on a model of the R Leo envelope suggest that the total column density can be as large as 7.0E+17 cm^{-2} and the abundance with respect to H2 ~2.5E-05. The detected lines are probably formed due to de-excitation of CO2 molecules from high energy vibrational states, which are essentially populated by the strong R Leo continuum at 2.7 and 4.2 um.
