论文标题
检测带有立方体的弱铍线
Detecting weak beryllium lines with CUBES
论文作者
论文摘要
铍是一种轻元素，具有一个单个稳定的同位素9BE，它是星际介质中宇宙射线剥落的纯乘积。晚期恒星中的铍丰度可用于有关进化混合，银河化学演化，行星吞噬和球状簇的形成的研究。在Cassegrain U波段有效光谱仪（立方）的科学案例中，其中一些用途是丰富的数字，这是一种新的近紫外和中分辨率光谱仪，正在开发非常大的望远镜。在这里，我们报告了一项有关在立方体A阶段A阶段，有关极为金属贫困恒星中的铍丰度的研究。我们的动机是了解在低含量的极为贫困的恒星中检测弱线的限制。我们基于[Fe/H] \ Leq -3.0的四个模拟恒星的合成光谱，分析了以中分辨率模式进行的模拟立方观测值。我们发现在某些情况下可以检测到BE线，但是非常具有挑战性，需要高信噪比。取决于目标恒星的大气参数，如果可以达到约400个像素的信噪，则应该检测到log（be/h）= -13.1和-13.6之间的丰度，并且典型的不确定性为\ pm 0.15 dex。使用立方体，可以获得有关恒星的所需数据，这些恒星因当前仪器的可能性而被两个幅度而言是淡淡的。
Beryllium is a light element with one single stable isotope, 9Be, which is a pure product of cosmic-ray spallation in the interstellar medium. Beryllium abundances in late-type stars can be used in studies about evolutionary mixing, Galactic chemical evolution, planet engulfment, and the formation of globular clusters. Some of these uses of Be abundances figure among the science cases of the Cassegrain U-Band Efficient Spectrograph (CUBES), a new near-UV low- and medium-resolution spectrograph under development for the Very Large Telescope. Here, we report on a study about beryllium abundances in extremely metal-poor stars in the context of the phase A of CUBES. Our motivation is to understand the limits for the detection of weak lines in extremely metal-poor stars of low Be abundances. We analyze simulated CUBES observations, performed in medium-resolution mode, based on synthetic spectra for four mock stars with [Fe/H] \leq -3.0. We find that detecting the Be lines is possible in certain cases, but is very challenging and requires high signal-to-noise ratio. Depending on the atmospheric parameters of the target stars, and if signal-to-noise per pixel of about 400 can be achieved, it should be possible to detect Be abundances between log(Be/H) = -13.1 and -13.6, with a typical uncertainty of \pm 0.15 dex. Using CUBES, the required data for such studies can be obtained for stars that are fainter by two magnitudes with respect to what is possible with current instrumentation.
