Galactic mass-losing AGB stars probed with the IRTS. II
Galactic mass-losing AGB stars probed with the IRTS. II
复制标题
DOI：
10.1051/0004-6361:20030461
复制
发表时间：
2001-09
影响因子：
6.5
通讯作者：
T. Bertre;Masahiro Tanaka;I. Yamamura;H. Murakami
中科院分区：
文献类型：
--
作者：
T. Bertre;Masahiro Tanaka;I. Yamamura;H. Murakami
我们正在使用日本空间实验 IRTS 2002 年发布的数据来研究星系质量损失 (>2 10 8 M yr 1 ) AGB 恒星的空间分布以及富含 C 和富含 O 的恒星对 ISM 补充的相对贡献。我们的样品包含 126 个富含 C 的源和 563 个富含 O 的源，这些源根据在 1.4-4.0 m 范围内观察到的分子带进行分类，并且我们通过近红外光度测定（K 和 L 0 ）估计了它们的距离和质量损失率。明显依赖于半乳中心距离，对于 rGC 10 kpc，富氧源的数量多于富碳源。富O AGB 恒星相对于富C 恒星对ISM 补充的贡献遵循相同的趋势。尽管它们很稀有（在我们的样本中为 10%），但 10 6 M yr 1 < ˙ M< 10 5 M yr 1 的来源主导了 ISM 的补充，占完整样本总数的 50%。我们发现了两颗距离银河平面超过 1 kpc 的碳星，它们可能属于我们银河系的光环。
We are using the 2002 data-release from the Japanese space experiment IRTS to investigate the spatial distribution of galactic mass-losing (>2 10 8 M yr 1 ) AGB stars and the relative contribution of C-rich and O-rich ones to the replenishment of the ISM. Our sample contains 126 C-rich and 563 O-rich sources which are sorted on the basis of the molecular bands observed in the range 1.4-4.0m, and for which we estimate distances and mass loss rates from near-infrared photometry (K and L 0 ). There is a clear dependence on galactocentric distance, with O-rich sources outnumbering C-rich ones for rGC 10 kpc. The contribution to the replenishment of the ISM by O-rich AGB stars relative to C-rich ones follows the same trend. Although they are rare (10% in our sample), sources with 10 6 M yr 1 < ˙ M< 10 5 M yr 1 dominate the replenishment of the ISM by contributing to50% of the total of the complete sample. We find 2 carbon stars at more than 1 kpc from the Galactic Plane, that probably belong to the halo of our Galaxy.