AKARI Infrared Camera Survey of the Large Magellanic Cloud.II. The Near-infrared Spectroscopic Catalog
AKARI Infrared Camera Survey of the Large Magellanic Cloud.II. The Near-infrared Spectroscopic Catalog
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AKARI 红外相机对大麦哲伦星云的勘测。II。
DOI：
10.1088/0004-6256/145/2/32
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发表时间：
2013
影响因子：
5.3
通讯作者：
下西 隆
中科院分区：
文献类型：
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作者：
Yamasaki H.;Sugiyama H.;Morishima Y.;下西 隆
我们利用红外卫星AKARI对大麦哲伦星云（LMC）的~ 10°2区域进行了近红外光谱调查。此次观测是AKARI大麦哲伦星云大面积巡天（LSLMC）的一部分。AKARI/IRC的无缝隙多目标光谱能力使我们能够获得LMC中大量点源的2-5 μm的低分辨率（R ~ 20）光谱。根据调查结果，我们提取了大约2000个点光源的红外光谱。这些数据被组织成一个近红外光谱目录。该目录包括各种红外天体，如年轻恒星天体（YSOs）、渐近巨星分支（AGB）恒星、超巨星等。结果表明，97%的星表源具有1.2 ~ 11 μm波长范围内的光度数据，67%的星表源具有24 μm波长范围内的光度数据。该星表允许我们通过比较它们的红外光谱能量分布来研究源的近红外光谱特征。此外，据估计，大约10%的星表源在两个以上不同的时期被观测到。这使我们能够利用目前的星表来研究光源的光谱变异性。给出了LSLMC样本源分类的初步结果。根据近红外光谱特征对659个LSLMC光谱进行了目视分类。结果表明，目前的星表包括7个yso， 160个富含c的AGB， 8个富含c的AGB候选，85个富含o的AGB， 122个蓝和黄超巨星，150个红超巨星和128个未分类的来源。文中讨论了分类源在色-色图和色-星等图上的分布。只有通过空间观测才能实现2-5 μm范围内的连续波长覆盖和高光谱灵敏度。这是一次前所未有的大尺度近红外光谱巡天。此次巡天提供的大量近红外光谱数据具有应用于各种研究的科学潜力。在本文中，我们介绍了光谱调查和目录的细节，并讨论了它的科学应用。
We performed a near-infrared spectroscopic survey toward an area of∼ 10 deg 2 of the Large Magellanic Cloud (LMC) with the infrared satellite AKARI. Observations were carried out as part of the AKARI Large-area Survey of the Large Magellanic Cloud (LSLMC). The slitless multi-object spectroscopic capability of the AKARI/IRC enabled us to obtain low-resolution (R∼ 20) spectra in 2–5 μm for a large number of point sources in the LMC. As a result of the survey, we extracted about 2000 infrared spectra of point sources. The data are organized as a near-infrared spectroscopic catalog. The catalog includes various infrared objects such as young stellar objects (YSOs), asymptotic giant branch (AGB) stars, supergiants, and so on. It is shown that 97% of the catalog sources have corresponding photometric data in the wavelength range from 1.2 to 11 μm, and 67% of the sources also have photometric data up to 24 μm. The catalog allows us to investigate near-infrared spectral features of sources by comparison with their infrared spectral energy distributions. In addition, it is estimated that about 10% of the catalog sources are observed at more than two different epochs. This enables us to study a spectroscopic variability of sources by using the present catalog. Initial results of source classifications for the LSLMC samples are presented. We classified 659 LSLMC spectra based on their near-infrared spectral features by visual inspection. As a result, it is shown that the present catalog includes 7 YSOs, 160 C-rich AGBs, 8 C-rich AGB candidates, 85 O-rich AGBs, 122 blue and yellow supergiants, 150 red super giants, and 128 unclassified sources. Distributions of the classified sources on the color–color and color–magnitude diagrams are discussed in the text. Continuous wavelength coverage and high spectroscopic sensitivity in 2–5 μm can only be achieved by space observations. This is an unprecedented large-scale spectroscopic survey toward the LMC in the near-infrared. A large number of near-infrared spectral data provided by the survey possess scientific potential that can be applied to various studies. In this paper, we present the details of the spectroscopic survey and the catalog, and discuss its scientific applications.