年別アーカイブ: 2017年

On-sky Closed-loop Atmospheric Dispersion Compensation: Demonstration of Sub-milliarcsecond Residual Dispersion Across H-band. / Chemical Abundances of Extremely Metal-Poor Turn-Off Star

[Speaker1]
Pathak Prashant, SOKENDAI D3 (Supervisor; Prof. Hideki Takami)
[Title]
On-sky Closed-loop Atmospheric Dispersion Compensation: Demonstration of Sub-milliarcsecond Residual Dispersion Across H-band.

[Speaker2]
Tadafumi Matsuno, SOKENDAI D1 (Supervisor; Wako Aoki)
[Title]
Chemical Abundances of Extremely Metal-Poor Turn-Off Star
[Abstract]
I will start my talk with introduction to the
Galactic Archaeology and metal-poor stars. In the latter part, we
present our latest results of abundance analysis for extremely
metal-poor turn-off stars. The discussion includes i) lithium
abundance below [Fe/H]=-3.5, ii) chemical inhomogeneity in the early
Universe in comparison to supernova yield with special focus on
[Na/Fe] bimodality, and iii) binary mass transfer of materials
enriched with slow neutron capture process elements enhancement and
thermohaline mixing.

Dense molecular outflows from the merging LIRG NGC3256 / Lyman-alpha emission as a tool to probe galaxy formation

[Speaker1]
Tomonari Michiyama, SOKENDAI D2 (Supervisor; Daisuke Iono)
[Title]
Dense molecular outflows from the merging LIRG NGC3256
[Abstract]
We report the new ALMA Cycle 3 results of line survey towards a late stage merging galaxy NGC 3256. NGC 3256 hosts two merging nuclei and the starburst and AGN activities are strongly affecting the chemical and physical properties of the ISM. We have detected more than 20 molecules (e.g., c-C3H2, H13CN, H13CO+, SiO, CCH, HCN, HCO+, HNC, CH3OH, CS, HC3N, CH3CCH, C18O, 13CO) at 2” angular resolution, which is high enough to resolve the double nuclei. In this presentation, we focus on CO, HCN and HCO+ to discuss the high velocity components detected only by those bright molecular lines. Such high velocity components are though to be molecular gas outflow from northern and southern nuclei. Including the CO(1-0) and CO(3-2) archived data, the line ratios suggest that (1) The excitation condition become weak towards edge of the outflow in the starburst triggered outflow. (2) In the case of low luminous AGN like southern nucleus in NGC 3256, the outflowing gas is associated with AGN jet, and warm and dense gas can be newly formed due to interaction between jet and ISM interaction.
(3) The HCN is enhanced due to shock especially in red-shifted outflow. In addition, we conducted radiative transfer modeling. By using a Bayesian likelihood analysis, we found that the CO column density and filling factor of outflowing gas is smaller than the gas around nuclei.

[Speaker2]
Satoshi Kikuta, SOKENDAI D1 (Supervisor; Masatoshi Imanishi)
[Title]
Lyman-alpha emission as a tool to probe galaxy formation
[Abstract]
Lyman-alpha emission line is the strongest line from astrophysical sources and can be used to probe galaxy formation especially at high-redshift (z>2) Universe. In this talk, I will review the basic physics about Lyman-alpha line and recent works on galaxy formation which used the line. Finally I will also talk about my research plan using the Lyman-alpha line from the gas in young galaxies around bright QSOs at z~3 to study the importance of gas in galaxy formation.

総研大・国立天文台 スプリングスクール2017

 2月27日(月)~3月2日(木)までの4日間、国立天文台三鷹キャンパスで、総研大・国立天文台スプリングスクールが開校されました。平成23年から始まったスプリングスクール。7回目を迎えた今回は、全国36大学から60名の参加者が集まりました。

最先端の研究者を講師陣として、理論天文学、電波天文学、光赤外線天文学、太陽物理学、装置開発の5つの天文学講義を4日間にわたって受講していただきました。

続きを読む