月別アーカイブ: 2017年5月

Survey Observations in the 45 GHz and 90 GHz Bands toward High-Mass Star-Forming Regions / Molecular Gas Obsarvation in Local Merging U/LIRGs

[Speaker1]
Kotomi Taniguch, SOKENDAI D3 (Supervisor; Masao Saito)
[Title]
Survey Observations in the 45 GHz and 90 GHz Bands toward High-Mass Star-Forming Regions
[Abstract]
We carried out survey observations of carbon-chain molecules and N2H+ in the 45 GHz and 90 GHz bands toward high-mass starless cores (HMSCs) and high-mass protostellar objects (HMPOs) with the Nobeyama 45-m radio telescope in the last two observational seasons. Our main purpose is to investigate the chemical evolution in the high-mass star-forming regions. We compare the I(N2H+)/I(HC3N) ratios using the 90 GHz band lines among HMSCs and HMPOs, and found that the ratios decrease from HMSCs to HMPOs, in contrast to the low-mass star-forming regions and giant molecular clouds. The column density of HC3N derived from 45 GHz line is well correlated with the integrated intensity of CCS, but that derived from 82 GHz line is not correlated. The high-excitation energy HC3N is enhanced in HMSCs where SiO has been detected. From these results, we propose that HC3N is re-generated in the shock regions driven by molecular outflows.

[Speaker2]
Misaki Ando, SOKENDAI D1 (Supervisor; Daisuke Iono)
[Title]
Molecular Gas Obsarvation in Local Merging U/LIRGs

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.