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.

对银心的红外巡天在J、H、K波段进行，分辨率为0.45英寸/像素。观测区域覆盖银纬±1度（±150 pc），银经±10度（±1.5 kpc）。我们使用同步红外成像仪进行无偏测量（SIRIUS），具有三个1024x1024碲镉汞 阵列，连接到位于名古屋大学南非天文台的 IRSF 1.4 米望远镜。阵列读数得到了改进，观测效率极高。这与文献中的颜色过量方法不同，而且更多 准确。星际消光偏离了里克-勒博夫斯基定律（与波长的-1.6级成比例），而是遵循波长的-2级。有时有人认为红外线消光在各种视线中是“普遍的”，但这一结果提供了明确的证据反对这一观点。确定的指数本身对于消除观察到的红化也很重要 然后，我们推导了银心周围±1.5 kpc区域的红团簇星分布峰值。视星等峰值沿银道面连续变化，在去红化后从 K=13.4 星等变为 12.2 星等。这种变化可以通过之前研究中发现的棒状结构来解释，但我们在直径 1.2 kpc 的区域内发现了一个额外的内部结构，其中表观震级峰值仅变化 0.1 弹力。

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。

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 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

TRISPEC: A Simultaneous Optical and Near‐Infrared Imager, Spectrograph, and Polarimeter

• DOI: 10.1086/431914
• 发表时间: 2005-07
• 期刊: Publications of the Astronomical Society of the Pacific
• 影响因子: 3.5
• 作者: Makoto Watanabe;H. Nakaya;T. Yamamuro;Takahiro Zenno;M. Ishii;M. Okada;A. Yamazaki;Yusuke Yamanaka-Yusuke

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