ELUCIDATION OF ORIGINS OF STELLAR MASS WITH WIDE FIELD IR SURVEYS: IMF IN STAR FORMATION

通过广域红外巡天阐明恒星质量的起源：恒星形成中的 IMF

• 批准号: 16340061
• 负责人: TAMURA Motohide
• 金额: $ 10.37万
• 依托单位: National Astronomical Observatory of Japan (NAOJ)
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2004
• 资助国家: 日本
• 起止时间: 2004 至 2006
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-16340061/
• 关键词: INFRARED; STAR FORMATION; BROWN DWARF; MASS FUNCTION; MOLECULAR CLOUD; POLARIZATION; VARIABILITY; 変光星

This research aims to establish the initial mass function (IMF) of stars, including very low-mass stars such as brown dwarfs and even planetary mass objects. In order to this, we have conducted very wide field infrared surveys of star forming regions. Since infrared surveys can uncover the embedded stellar clusters whose mass distribution reflects the IMF. In addition, because the young stars are relatively bright at infrared due to their gravitational energy, we can detect down to very low mass stars. We can distinguish young stars from background stars taking into account their color and polarization information. The mains results are summarized as follows:(1)We conducted observations of nearby star forming regions. with the IRSF 1.4m telescope in South Africa, the Subaru and Gemini telescopes in Hawaii. Those at IRSF were conducted with the SIRIUS JHKs-band simultaneous camera, which was developed by NAOJ and Naoya University. The observed regions are Oph, Cha, R CrA, Orion, Vela, Cygnus molecular clouds. We have detected a number f new brown dwarfs and planetary mass candidates in some regions. The results for Orion, S106, and Vela regions were already published in refereed journals. We have discovered the universality of brown dwarfs and the relative populations of very low mass stars to low mass stars vary from region to region.(2)We discovered the middle mass young stars in the Magellanic Bridge (published in refereed journal).(3)We developed wide field infrared polarimeter for IRSF/SIRIUS and conducted polarization observations. We detected a number of new circumstellar structures.(4)We conducted photometry and spectroscopy of the Oph cloud core and found lowest mass candidates.

这项研究旨在建立恒星的初始质量函数（IMF），包括非常低质量的恒星，如褐矮星，甚至行星质量的天体。为此，我们对星星形成区进行了大视场红外巡天。由于红外巡天可以发现嵌入的星团，其质量分布反映了IMF。此外，由于年轻恒星的引力能量，它们在红外线下相对明亮，我们可以探测到非常低质量的恒星。我们可以通过考虑它们的颜色和偏振信息来区分年轻恒星和背景恒星。主要结果如下：（1）对附近的星星形成区进行了观测。与南非的IRSF 1.4米望远镜，夏威夷的斯巴鲁和双子座望远镜。IRSF的这些都是用SIRIUS JHKs波段同步相机进行的，该相机由NAOJ和Naoya大学开发。观测到的区域是Oph、Cha、R CrA、Orion、Vela、Cygnus分子云。我们在某些区域发现了一些新的褐矮星和行星质量候选者。猎户座，S106和船帆座区域的结果已经发表在参考期刊上。我们已经发现了褐矮星的普遍性，以及极低质量恒星与低质量恒星的相对种群在不同地区的差异。(2)We在麦哲伦桥发现了中等质量的年轻恒星（发表在参考期刊上）。(3)We为IRSF/SIRIUS开发了宽视场红外偏振计，并进行了偏振观测。我们发现了一些新的星周结构。(4)We对Oph云核进行了光度测定和光谱分析，并找到了质量最低的候选者。

项目成果

Simultaneous X-ray, radio, near-infrared, and optical monitoring of young stellar objects in the Coronet cluster

对冠状星团中的年轻恒星进行同步 X 射线、射电、近红外和光学监测

• 发表时间: 2007
• 期刊: Astronomy and Astrophysics 464
• 作者: Wimbush SC;et al.;J.Forbrich ほか
• 通讯作者: J.Forbrich ほか

Near-Infrared Polarization Images of the Orion Nebula

• DOI: 10.1086/508168
• 发表时间: 2006-09
• 期刊: The Astrophysical Journal Letters
• 作者: M. Tamura;R. Kandori;N. Kusakabe;Y. Nakajima;J. Hashimoto;C. Nagashima;T. Nagata;T. Nagayama;H. Kimura;T. Yamamoto;J. Hough;P. Lucas;A. Chrysostomou;J. Bailey

Near-infrared photometric monitoring of the pre-main-sequence object KH 15D

前主序天体 KH 15D 的近红外光度监测

• 发表时间: 2005
• 期刊: Astrophysical Journal 632
• 作者: Sako;S. ほか;Y.Kohsaka;H.Kaneda;N.Kusakabe
• 通讯作者: N.Kusakabe

Near-Infrared Extinction Law in the rho Ophiuchi and Chamaeleon Dark Clouds

蛇夫座和变色龙暗云中的近红外消光定律

• 发表时间: 2006
• 期刊: Astrophysical Journal 640
• 作者: Naoi;T.;Tamura;M.ほか
• 通讯作者: M.ほか