Infrared Survey of the Galactic Center with the 1.4-m IRSF telescope at SAAO

使用 SAAO 的 1.4 米 IRSF 望远镜对银河系中心进行红外巡天

• 批准号: 15340061
• 负责人: NAGATA Tetsuya
• 金额: $ 9.98万
• 依托单位: Kyoto University (2004-2005)Nagoya University (2003)
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2003
• 资助国家: 日本
• 起止时间: 2003 至 2005
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-15340061/
• 关键词: optical infrared telescope; infrared survey; Galactic center; Galaxy; interstellar dust; interstellar extinction; red clump stars; Galactic structure

Infrared survey of the Galactic center has been performed in the J, H, and K bands with the high resolution of 0.45"/pix. The observed area covers ±1 deg (±150 pc) in the Galactic latitude and ±10 deg (±1.5 kpc) in the Galactic longitude. We used Simultaneous Infrared Imager for Unbiased Survey (SIRIUS) with three 1024x1024 HgCdTe arrays, which were attached to the IRSF 1.4-m telescope placed at South African Astronomical Observatory by Nagoya University. The array read-out has been improved and the efficiency of the observation is now extremely high.First, using the detected red clump stars in the central degree, which are in the core He burning phase, we determined the interstellar reddening law ; this is different from the color-excess method in the literature, and much more accurate. The interstellar extinction is deviated from the Rieke-Lebofsky law (proportional to the -1.6th order of the wavelength), and rather follows to the -2nd order of the wavelength. It has been sometimes argued that the infrared extinction is "universal" in the various lines of sight, but this result has presented clear evidence against it. The determined index itself is also important in dereddening the observed spectra.Then, we derived the peak of distribution of red clump stars in the ±1.5 kpc region around the Galactic center. The apparent magnitude peak changes continuously along the Galactic plane, from K=13.4 mag to 12.2 mag after dereddening. This variation is explained by the bar-like structure found in previous studies, but we find an additional inner structure within the region of 1.2 kpc in diameter, where the apparent magnitude peak changes by only 0.1 mag.

对银河中心的红外调查已在J，H和K带中进行，高分辨率为0.45“/PIX。观察到的面积覆盖了银河纬度的±1度（±150 pc），±10 deg，±1.5 deg（±1.5 kpc）（±1.5 kpc）（我们在银河系中）使用了同步的Infrared Imaster（Sirius）。阵列附着在纳戈亚大学（Nagoya University）上放置在南非天文观测的IRSF望远镜。准确。星际延伸与Rieke -Lebofsky定律偏离（与波长的-1.6级成比例），而是遵循波长的-2级。确定的指数本身对于驱除观察到的光谱也很重要。然后，我们得出了在银河系中心周围±1.5 kpc区域中红色恒星分布的峰值。沿银河平面沿着银河平面连续变化，从k = 13.4 mag到德雷德登之后的12.2 mag。这种变化是通过先前研究中发现的类似条形结构来解释的，但是我们在直径1.2 kpc的区域内发现了一个额外的内部结构，在该区域中，表观幅度的峰值仅变化0.1 mag。

项目成果

Nagashima, C.: "An Optical and Near Infrared Search for Brown Dwarfs in the Pleiades Cluster"Mon.Not.R.Astron.Soc. 343. 1263-1270 (2003)

Nagashima, C.：“对昴宿星团中褐矮星的光学和近红外搜索”Mon.Not.R.Astron.Soc。

A Distinct Structure inside the Galactic Bar

• DOI: 10.1086/429291
• 发表时间: 2005-02
• 期刊: The Astrophysical Journal Letters
• 作者: S. Nishiyama;T. Nagata;D. Baba;Y. Haba;R. Kadowaki;D. Kato;M. Kurita;C. Nagashima;T. Nagayama;Yuka Murai;Y. Nakajima;M. Tamura;H. Nakaya;K. Sugitani;T. Naoi;N. Matsunaga;T. Tanabé;N. Kusakabe;S. Sato

A deep near-infrared survey around the giant radio galaxy PKS 1343-601

围绕巨大射电星系 PKS 1343-601 的深度近红外巡天

• 发表时间: 2004
• 期刊: Mon.Notes Roy.Astron.Soc. 354
• 作者: Nagayama;T
• 通讯作者: T

Interstellar Extinction Law in the J, H, and Ks Bands toward the Galactic Center

• DOI: 10.1086/499038
• 发表时间: 2006-01
• 期刊: The Astrophysical Journal
• 作者: S. Nishiyama;T. Nagata;N. Kusakabe;N. Matsunaga;T. Naoi;D. Kato;C. Nagashima;K. Sugitani;M. Tamura

A Near-Infrared Study of the NGC 7538 Star-forming Region

• DOI: 10.1086/425068
• 发表时间: 2004-08
• 期刊: The Astrophysical Journal
• 作者: D. Ojha;M. Tamura;Y. Nakajima;M. Fukagawa;K. Sugitani;C. Nagashima;T. Nagayama;T. Nagata;S. Sato;S. Vig;S. Ghosh;A. Pickles;M. Momose;K. Ogura