RED SUPERGIANT STARS AS COSMIC ABUNDANCE PROBES: KMOS OBSERVATIONS IN NGC 6822
RED SUPERGIANT STARS AS COSMIC ABUNDANCE PROBES: KMOS OBSERVATIONS IN NGC 6822
复制标题
DOI：
10.1088/0004-637x/803/1/14
复制
发表时间：
2015-01
期刊：
影响因子：
--
通讯作者：
L. Patrick;Chris Evans;Chris Evans;Ben Davies;R. Kudritzki;J. Gazak;M. Bergemann;B. Plez;A. Ferguson
中科院分区：
文献类型：
--
作者：
L. Patrick;Chris Evans;Chris Evans;Ben Davies;R. Kudritzki;J. Gazak;M. Bergemann;B. Plez;A. Ferguson
我们目前的近红外光谱的红超巨星（RSG）在NGC 6822，获得了新的K波段多目标光谱仪甚大望远镜，智利。通过与J波段的模型光谱的比较，我们确定了11个RSG的金属丰度，发现平均值[Z] = −0.52 ± 0.21，这与之前对年轻恒星和H ii区的丰度研究结果一致。我们还发现了一个低显着的丰度梯度内的中央1千秒差距的迹象。我们比较我们的结果与来自较老的恒星种群和调查的差异，使用一个简单的化学演化模型。通过比较确定的物理性质的RSG在NGC 6822与那些使用相同的技术在银河系和麦哲伦云，我们发现，似乎没有显着的温度变化的RSG相对于金属丰度，在最近的进化模型。
We present near-IR spectroscopy of red supergiant (RSG) stars in NGC 6822, obtained with the new K-band Multi-Object Spectrograph Very Large Telescope, Chile. From comparisons with model spectra in the J-band we determine the metallicity of 11 RSGs, finding a mean value of [Z] = −0.52 ± 0.21, which agrees well with previous abundance studies of young stars and H ii regions. We also find an indication for a low-significance abundance gradient within the central 1 kpc. We compare our results with those derived from older stellar populations and investigate the difference using a simple chemical evolution model. By comparing the physical properties determined for RSGs in NGC 6822 with those derived using the same technique in the Galaxy and the Magellanic Clouds, we show that there appears to be no significant temperature variation of RSGs with respect to metallicity, in contrast to recent evolutionary models.