论文标题
红色壳富氧和富含碳的AGB恒星之间的红外颜色分离
Infrared color separation between thin-shelled oxygen-rich and carbon-rich AGB stars
论文作者
论文摘要
我们为51个AGB源提供了43 GHz VLA光谱，目的是验证用于分离整个银河系中富含碳富含碳（C）和富含氧气（O）AGB源的红外（IR）颜色。颜色切割是$ [k_s] - [a] $ vors $ [a] - [e] $颜色图基于2mass和MSX光度法的简单线，最初是从凸起的不对称和动态进化（BAADE）样本中的SIO检测率得出的。该部门得到了此处介绍的光谱的完全支持，该光谱表明Sio Maser的检测位于O富含O的一侧，Sio非详细信息和单个HC $ _3 $ n检测在该部门的C-Rich侧发现。我们进一步将颜色切割与基于红外天文卫星（IRAS）的低分辨率光谱（LRS）的分类进行比较，并找到良好的一致性，验证该分裂是区分O-和C-富含AGB源的可靠和有效方法。这些观察结果还表明，在42.9 GHz大约42.9 GHz左右检测到的单行线几乎可以肯定是$^{29} $ sio v = 0行。 Sio Maser来源以前尚未报告这种罕见的同位素学过渡比主要的$^{28} $ SIO线更明亮，而且我们的观察结果表明，这些来源可以逆转其行为，以便在几年内恢复了$^{28} $ sio和$^{29} $ sio的典型比率。
We present 43 GHz VLA spectra for 51 AGB sources with the goal of verifying an infrared (IR) color cut intended to separate Carbon-rich (C) and Oxygen-rich (O) AGB sources throughout the Galaxy. The color cut is a simple line in the $[K_s]-[A]$ versus $[A]-[E]$ color-color diagram based on 2MASS and MSX photometry, and was originally derived from SiO detection rates in the Bulge Asymmetries and Dynamical Evolution (BAaDE) sample. The division is fully supported by the spectra presented here, which show that SiO maser detections lie on the O-rich side, and SiO nondetections and a single HC$_3$N detection are found on the C-rich side of the division. We further compare the color cut with classifications of the sources based on Low-Resolution Spectra (LRS) from the Infrared Astronomical Satellite (IRAS), and find good agreement, verifying that the division is a reliable and efficient method for differentiating O- and C-rich AGB sources. These observations also demonstrate that single lines detected in the BAaDE survey around 42.9 GHz are almost certainly the $^{29}$SiO v=0 line. SiO maser sources where this rare isotopologue transition is brighter than the dominant $^{28}$SiO lines have not been reported before, and our observations show that these sources can reverse their behavior such that the typical ratios of $^{28}$SiO and $^{29}$SiO are restored within a few years.
