[Speaker 1]
Rhythm Shimakawa M2, SOKENDAI, Mitaka（supervisor : Kodama Tadayuki）
[Title]
Metal enhancement of the protocluster galaxies at z=2.2
[Abstract]
Protoclusters are the ideal laboratories to study how the strong environmental dependence in galaxy properties seen today was initially set up. We conducted a near-infrared spectroscopy of star-forming galaxies (H-alpha emitters) associated with two protoclusters at z=2.2&2.5 with MOIRCS/Subaru.
Shimakawa et al. (2014) have confirmed that the two protoclusters are the right ancestors of today’s largest clusters like ‘Coma’, and now we are studying the physical characteristics of the memberships in the respective protoclusters.
This talk focuses on one of our recent results regarding the environmental dependence of mass-metallicity relation seen in the protocluster, PKS1138-262 at z=2.2. The mass-metallicity relation provides crucial insights into star formation history, gaseous inflows and outflows.
As a result, we find a clear excess of the gaseous metallicities of the protocluster galaxies at the stellar mass of < 1E11 Msun. We suggest that it can be explained by the 'downsizing effect' or 'gas recycling' in the protocluster region.

3月31日、三鷹キャンパスにて専攻修了式が執り行われました。
平成25年度修了生のうち4名が出席し、教員・在学生に盛大に見送られました。

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3月10日（月）～13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。4回目を迎えた今回は、全国26大学・高専から46名もの参加者が集まりました。
装置開発を含む最先端の天文学の基礎を学ぶということで、今年は、5名の講師が、電波天文学、太陽物理学、理論天文学、星間物理学、光赤外線天文学と幅広い分野の講義を担当しました。

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[Speaker 1]
Nobuyuki Sakai D3, SOKENDAI, Mitaka（supervisor : Mareki Honma）
[Title]
The first astrometry result of the Perseus arm beyond a Galactic longitude l of ~ 190 deg with VERA
[Abstract]
Contexts. Currently, VERA and VLBA have been conducting kpc-scales astrometry to make a 3D map of the Milky Way Galaxy.
AIms. We aim to expand previous astrometry coverage of the Perseus arm from a Galactic longitude l of ~ 190 deg to that of ~ 240 deg.
This is crucial to accurately understand large scale structure of the Perseus arm.
Methods. We carried out nine-epochs VERA astrometry observations toward massive star-forming region IRAS 07427-2400 (l = 240.3 deg, b = 0.1 deg, Vlsr = 68.0 km/s) between January 20, 2012 and September 16, 2013.
Results. The measured parallactic distance is 5.18 +0.79/-0.59 kpc, which places the source in the 3rd Galactic quadrant of the Perseus arm.
Discussions. A combination of our astrometry result and previous ones reveal that the pitch angle of the Perseus arm is constant (i = 17.7 +/- 1.8 deg) in 94.60 deg < l < 240.32 deg, although the pitch angle is changed significantly (i = 11.5 +/- 1.3 deg) in 43.17 deg < l < 94.60 deg. The difference indicates that bifurcation or spur as seen in external disk galaxies may occur in 43.17 deg < l < 94.60 deg for the Perseus arm. [Speaker 2] Shino Nagisa D2, SOKENDAI, Mitaka（supervisor : Mareki Honma） [Title] Methanol maser observation of massive star formation region IRAS 18089-1732 [Abstract] The formation scenario of massive star is not yet fully understand. Methanol maser is regarded as the signpost of the formation process of the massive star. Particular, the 44GHz methanol maser is associated with an outflow, and it is said that the 6.7GHz methanol maser is associated with an accretion disk. If this is true, 44GHz methanol maser is expected to be distributed perpendicularly with respect to rotating disk. Detecting (or rejecting) this will play a major role in understanding the scenario of massive star formation. In order to test this, we observed 6.7GHz methanol maser using JVN and obtained space distribution map. We also analyzed the VLA archive data of the 44GHz methanol maser. We were able to get the space distribution map of the 44GHz methanol maser and the 6.7GHz methanol maser of IRAS18089-1732. We argue about each emission position from the result.

[Speaker 1]
Ryosuke Nagasawa, M1, SOKENDAI, Mitaka（supervisor : Hideo Hanada）
[Title]
Development of software for high-precision LLR data analysis
[Abstract]
We are developing new analysis software for precise determination of lunar orbital/rotational motion and tidal deformation using lunar laser ranging (LLR) observation data.
As the first step of the study, we construct an LLR observation model. This model consists of the lunar orbit and libration obtained from lunar-planetary ephemeris DE430 (provided by NASA JPL), and the other newest physical models compatible with IERS Conventions (2010) such as Earth orientation, solid Earth/Moon tides, and some factors affecting propagation delay. For the purpose of calculating these components precisely, we use the modules of the geodetic data analysis software “c5++” (Otsubo et al., Japan Geoscience Union Meeting 2011). LLR observation data are provided as normal points. In this calculation, there are 3577 points distributed from June 1996 to July 2013, obtained at 4 observatories: Apache Point, Grasse, Matera and McDonald. Comparing the observed and calculated one-way ranges, the mean and the standard deviation of the residuals are about 5.7 cm and 4.8 cm respectively.
The first step has almost finished. Currently we are working on the next step, the integration of lunar motion. This presentation contains the outline of LLR and the current status of the software development, including the details of above-mentioned modeling.

[Speaker 2]
Sumire Tatehora, D1, SOKENDAI, Mitaka（supervisor : Nobuo Arimoto）
[Title]
Morphological studies of high-z massive galaxies
[Abstract]
Thanks to the Cosmic Assembly Near-IR Deep Extragalactic Legacy Survey (CANDLES) HST/WFC3 imaging with high spatial resolution, we investigate the morphology of galaxies in the distant universe. We select 20 passively evolving galaxies and 586 star-forming galaxies at 1.4＜phot-z＜2.5 in the COSMOS-CANDELS 210 square arcmin field and measure effective radius and Se ́rsic index by using the GALFIT package (Peng et al. 2002). We present the results of size-mass, Se ́rsic index-mass relation and discuss whether it has correlation between galaxy morphology and BzK color.