科研团队：天文

主要研究方向(Main Research Direction)：

Construction of a database of circumstellar maser sources, Searching very young post-AGB stars with a tiny molecular jet, Radio and infrared imaging of post-AGB stars with a molecular jet, Case studies of stellar merger remnants.

建立恒星周围脉泽源数据库，寻找非常年轻的post-AGB恒星与微小的分子射流，无线电和红外成像post-AGB恒星与分子射流，恒星合并残留物的案例研究。

通讯地址(Mailing Address)：中国广东省珠海市香洲区唐家湾大学路2号 中山大学开云手机登录中心,开云(中国) 天琴中心3413室 邮编：519082

Email: junichin@mail.sysu.edu.cn

个人简介: 

My scientific interests have covered astrophysical maser, maser pumping mechanism, stellar evolution of its late stage, circumstellar chemistry, galactic dynamics of stellar components, and radio/infrared astronomy. Recently, my interests also expand to clusters of red supergiants, stellar merger, and database astronomy.

 

(1) In recent years, I have been leading an international collaboration team for developing a database of astrophysical maser sources. Astrophysical maser is the natural microwave laser emission emitted from celestial objects. Astrophysical masers, which are non-linearly strongly amplified microwave emission, could be a useful probe to reveal the physical conditions of celestial objects, such as the kinematics, temperature and density of molecular gas. Unfortunately, however, the observational results of circumstellar masers have not been well organized into a single organized database. I'm currently collecting and organizing the maser data (particularly, on silicon-monoxide masers) for the purpose of statistical analysis of maser data of evolved stars.

 

(2) The database mentioned in (1) has various possibilities for the scientific application. Our group have utilized the database to find evolved stars with an extremely tiny molecular jet, which is a key object to understand the morphological evolution of circumstellar envelopes. The morphological evolution of stellar envelope in its late stage is a fundamental information to consider dynamical and chemical evolution of evolved stars and interstellar space.

 

科研兴趣包括天体物理脉泽、脉泽抽运机制、恒星后期演化、恒星周围化学、恒星组分的银河动力学和射电/红外天文学。最近，我的兴趣也扩展到了红超巨星集群、恒星合并和数据库天文学。  

一、近年来，我一直在领导一个国际合作小组，开发一个天体物理脉泽源数据库。天体物理脉泽是天体发射的自然微波激光。天体物理脉泽是一种非线性强放大的微波辐射源，可以用来探测天体的运动、温度和分子气体密度等物理条件。然而，不幸的是，恒星周围脉泽的观测结果并没有很好地组织成一个单一的有组织的数据库。我目前正在收集和组织脉泽数据（特别是在硅氧化物脉泽上），用于对演化恒星的脉泽数据进行统计分析。             

二、上述（1）中所述数据库具有多种科学应用的可能性。我们的研究小组利用这个数据库发现了具有极其微小的分子喷流的演化恒星，这是理解恒星周界形态演化的关键。恒星包层后期的形态演化是研究恒星演化和星际空间演化的基本信息。

研究领域: 

evolved stars, stellar mass-loss, circumstellar molecules,astrophysical masers, radio astronomy.

教育背景: 

1991.04 – 1995.03      日本冈山理科大学，应用物理专业，理学学士

1997.04 – 1999.03      日本大阪教育大学，科学教育专业，教育学硕士

1999.04 – 2002.03 日本总合研究大学院大学，天文学专业，理学博士

职业经历: 

2002.04 – 2002.10     日本国立天文台野边山宇宙电波观测所，研究助理

2002.11 – 2005.04     美国伊利诺伊大学香槟分校天文系，博士后

2005.05 – 2007.08     中国台湾中央研究院天文及天文物理研究所，博士后

2007.09 – 2013.08     中国香港特别行政区香港大学物理系，助理教授

2008.03 – 2015.02     中国香港特别行政区香港大学物理系，名誉助理教授

2013.11 – 2013.12     俄罗斯乌拉尔联邦大学天文与大地测量系，访问科学家

2014.05 – 2015.02     俄罗斯乌拉尔联邦大学天文与大地测量系，杰出研究员

2015.03 – 2019.09     俄罗斯乌拉尔联邦大学天文与大地测量系，教授

2019.11至今             中山大学开云手机登录中心,开云(中国)，教授

代表性论文: 

1."Wide Field CO Mapping in the Region of IRAS 19312+1950"

Nakashima, J., Sobolev, A. M., Ladeyschikov, D. A., Zhang, Y., Hsia, C. -H., Yung, B. H. K.2016, ApJ, 825, 16

2."Methanol observation of IRAS 19312+1950: A possible new type of class I methanol maser"

Nakashima, J., Sobolev, A. M., Salii, S., Deguchi, S., Yung, B. H. K., Zhang, Y.2015, PASJ, 67, id.9512

3."CO Structure of the 21 Micron Source IRAS 22272+5435: A Sign of a Jet Launch?"

Nakashima, J., Koning, N., Volgenau, N. H., Kwok, S., Yung, B. H. K., Zhang, Y.2012, ApJ, 759, 61

4."Maser Properties of the Enigmatic IRAS Source IRAS 19312+1950"

Nakashima, J., Deguchi, S., Imai, H., Kemball, A., Lewis, B. M.2011, ApJ, 728, 76

5."Do Water Fountain Jets Really Indicate the Onset of the Morphological Metamorphosis of Circumstellar Envelopes?"

Yung, B. H. K., Nakashima, J., Hsia, C. -H., Imai, H.2017, MNRAS, 465, 4482

6."Maser and Infrared Studies of Oxygen-Rich Late/Post-AGB Stars and Water Fountains: Development of a New Identification Method"

Yung, B. H. K., Nakashima, J., Henkel, C.2014, ApJ, 794, 81

7."Exploration of a Relic Circumstellar Envelope in the Water Fountain Source IRAS 18286-0959"

Imai, H., Nakashima, J., Yung, B. H. K., Deguchi, S., Kwok, S., Diamond, P. J.2013, ApJ, 771, 47

8."Water Maser Survey on AKARI and IRAS Sources: A Search for "Low-velocity" Water Fountains"

Yung, H. K. B., Nakashima, J., Imai, H., Deguchi, S., Henkel, C.2013, ApJ, 769, 20

9."Maser Observations of Westerlund 1 and Comprehensive Considerations on Maser Properties of Red Supergiants Embedded in Massive Clusters"

Fok, T. K. T., Nakashima, J., Yung, B. H. K., Hsia, C. -H., Deguchi, S.2012, ApJ, 760, 65