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arXiv 0903.2238astro-ph.GA
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用Spitzer/GLIMPSE图像探测银河系星团的近红外光谱

Near-infrared spectra of Galactic stellar clusters detected on Spitzer/GLIMPSE images

Maria Messineo, Ben Davies, Valentin D. Ivanov, Donald F. Figer, Frederic Schuller, Harm J. Habing, Karl M. Menten, Monika G. Petr-Gotzens

摘要:

我们目前的近红外光谱观测的大质量恒星在三个星团位于内银河系的方向。其中一个,四重奏,是一个新发现,而其他两个以前被报道为候选集群上确定的中红外斯皮策图像(GLIMPSE 20和GLIMPSE 13)。使用中等分辨率(R=900-1320)的H和K光谱,我们坚定地建立在这些集群中最亮的恒星的性质,产生新的识别早期WC和两个Ofpe/WN 9星的四重奏和早期WC星GLIMPSE 20。我们将这些信息与2 MASS提供的光度测量相结合,以估计星系团的质量,年龄和距离。几颗大质量恒星的存在使四重奏和GLIMPSE 20成为已知银河系星团中质量只有几个10^3 M太阳,年龄在300万年到800万年之间的小样本。我们估计Glimpse 20的距离约为3.5 kpc,Quartet为6.0 kpc。在GLIMPSE 13中发现的大量巨星表明它是另一个大质量(~ 6500 Msun)星团,但年龄更大,年龄在3000万年到1亿万年之间,距离约为3 kpc。

英文摘要:

We present near-infrared spectroscopic observations of massive stars in three stellar clusters located in the direction of the inner Galaxy. One of them, the Quartet, is a new discovery while the other two were previously reported as candidate clusters identified on mid-infrared Spitzer images (GLIMPSE20 and GLIMPSE13). Using medium-resolution (R=900-1320) H and K spectroscopy, we firmly establish the nature of the brightest stars in these clusters, yielding new identifications of an early WC and two Ofpe/WN9 stars in the Quartet and an early WC star in GLIMPSE20. We combine this information with the available photometric measurements from 2MASS, to estimate cluster masses, ages, and distances. The presence of several massive stars places the Quartet and GLIMPSE20 among the small sample of known Galactic stellar clusters with masses of a few 10^3 Msun, and ages from 3 to 8 Myr. We estimate a distance of about 3.5 kpc for Glimpse 20, and 6.0 kpc for Quartet. The large number of giant stars identified in GLIMPSE13 indicates that it is another massive (~ 6500 Msun) cluster, but older, with an age between 30 and 100 Myr, at a distance of about 3 kpc.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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