论文标题
GAIA-EDR3的银河碳星和相关恒星的表征
Characterisation of Galactic carbon stars and related stars from Gaia-EDR3
论文作者
论文摘要
我们在这里使用更准确的EDR3天文测量值扩展了对银河碳恒星特征的研究。基于更大的统计数据，我们确认N-和SC型碳星具有非常相似的光度函数，而J型恒星（MBOL）的发光度平均缩小了一半。 R-HOT型碳星在整个RGB中具有亮度，这有利于外部起源的假设以增强其碳。此外，与N-和SC-type恒星相比，R-HOT恒星很大一部分的运动学特性与厚盘人群兼容，而N-和SC型恒星主要属于薄磁盘。我们还得出了大量银河外部和内在（O-富含O的）恒星的光度函数，并表明后者的发光度通常高于太阳金属性AGB期间第三次挖掘的预测发作。该结果与这些恒星是真正的热脉冲AGB恒星一致。另一方面，使用所谓的GAIA-2MASS图，我们表明，在Lamost调查中鉴定为AGB恒星的绝大多数碳星可能是R型旋转和/或CH-TYPE恒星。最后，我们报告了通过其2个肿块的光度法，其GAIA星形法及其在GAIA-2MASS图中的位置来确定的2660个新碳星候选候选者的鉴定。
We extend here a previous investigation on the characteristics of Galactic carbon stars using more accurate EDR3 astrometry measurements. Based on a much larger statistics, we confirm that N- and SC-type carbon stars share a very similar luminosity function, while the luminosities of J-type stars (Mbol) are fainter by half a magnitude on average. R-hot type carbon stars have luminosities throughout the RGB, which favours the hypothesis of an external origin for their carbon enhancement. Moreover, the kinematic properties of a significant fraction of the R-hot stars are compatible with the thick-disc population, in contrast with that of N- and SC-type stars, which would belong mostly to the thin disk. We also derive the luminosity function of a large number of Galactic extrinsic and intrinsic (O-rich) S stars and show that the luminosities of the latter are typically higher than the predicted onset of the third dredge-up during the AGB for solar metallicity. This result is consistent with these stars being genuine thermally pulsing AGB stars. On the other hand, using the so-called Gaia-2MASS diagram, we show that the overwhelming majority of the carbon stars identified in the LAMOST survey as AGB stars are probably R-hot and/or CH-type stars. Finally, we report the identification of 2660 new carbon stars candidates that we identified through their 2MASS photometry, their Gaia astrometry, and their location in the Gaia-2MASS diagram.
