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国立天文台野辺山談話会 : NRO Colloquium

日時
  • 毎週火曜日 15:00-16:00
場所
  • 国立天文台野辺山宇宙電波観測所 輪講室 (本館2階)

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次回のお知らせ

日時 / 場所 2017/12/05 (火), 15:00-16:00 / 輪講室
講演者 Gwanjeong Kim (NRO)
タイトル Dense Molecular Cores Being Externally Heated
概要 Can external effects make dense cores unstable? In order to find answer on this question, I selected eight dense cores which were classified as starless from previous literatures, and conducted infrared (3–160 μm) imaging observations with the AKARI telescope and molecular line (HCN and N2H+) mapping observations with the KVN telescope. Combining these data with the archival data, I again examined the starless nature of these eight cores. Two of the eight cores are found to harbor faint protostars having luminosities of ~0.3–4.4 Lsun. The other six cores are found to remain starless and probably are in a dynamically transitional state. For the six starless cores, I analyzed their temperature map, virial parameter, and line asymmetry. Their temperature maps show an enhancement of about 3–6 K toward the outer boundary of these cores, suggesting that they are most likely being heated externally by nearby stars and/or interstellar radiation fields. They also show large virial parameters and an overdominance of red asymmetric line profiles over them, indicating that they are set into either an expansion or an oscillatory motion, probably due to the external heating. In addition, I found that most of the starless cores show a coreshine effect due to the scattering of light by the micron-sized dust grains. This may imply that the age of the cores is of the order of ~10^5 years, which is consistent with the timescale required for the cores to evolve into an oscillatory stage due to external perturbation. Therefore these observational results give us positive answer supporting that the external feedback from nearby stars and/or interstellar radiation fields may play an important role in the dynamical evolution of the cores.
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過去の談話会

日付 タイトル/講演者
2017-12-05 TBD
Gwanjeong Kim (NRO)

昨年度以前の談話会

世話人

2017年度

  • 宮本祐介

2016年度

  • 宮本祐介

2015年度

  • 宮本祐介
  • 西村淳

2014年度

  • 岩井一正
  • 諸隈佳菜