6月18日（月）13:30～15:00 太陽系小天体セミナー 南棟2F 会議室
Jun 18 Mon Solar System Minor Body Seminar Conference Room, South Bldg. 2F
6月20日（水）10:30～12:00 総研大コロキウム 中央棟（北）1F 講義室
Jun 20 Wed SOKENDAI Colloquium Lecture Room
6月20日（水）15:00～16:00 VLBIコロキウム 中央棟（南）2F VLBIセミナー室
Jun 20 Wed VLBI Colloquium VLBI Seminar Room, Main Bldg. (South) 2F
6月22日（金）15:00～16:00 VLBIコロキウム 中央棟（南）2F VLBIセミナー室
Jun 22 Fri VLBI Colloquium VLBI Seminar Room, Main Bldg. (South) 2F
詳細は以下をご覧下さい。
6月18日(月)
- キャンパス
- 三鷹
- セミナー名
- 太陽系小天体セミナー
- 臨時・定例の別
- 定例
- 日時
- 6月18日（月）13:30～15:00
- 場所
- 南棟2階会議室
- 講演者
- 臼井文彦
- 所属
- JAXA
- タイトル
- 『赤外線サーベイ衛星による小惑星カタログの比較研究 — IRAS, あかり, WISE』
- Abstract
- これまでに、赤外線衛星 IRAS、あかり、WISE によって、全天サーベイ観測が行われてきた。それぞれの観測データから小惑星のサイズアルベドに関するカタログが構築されている。今回のゼミでは、各データを比較検討し、それぞれの特徴を議論する。
- 連絡先
- 名前：渡部潤一
- 備考
- テレビ会議またはスカイプによる参加も可
- Campus
- Mitaka
- Seminar
- Solar System Minor Body Seminar
- Regular/Irregular
- Regular
- Date
- June 18th 13:30～15:00
- Place
- the Conference Room of South Building (2F), NAOJ
- Speaker
- Fumihiko Usui
- Affiliation
- JAXA
- Contents
- A Comparative Study of Infrared Asteroid Surveys: IRAS, AKARI, and WISE
- Facilitator
- Name：Jun-ichi Watanabe
- Comment
- ・welcome to participate via TV conference system or Skype system
6月20日(水)
- Campus
- Mitaka
- Seminar Name
- SOKENDAI colloquium
- Regular / Irregular
- Regular
- Date
- 10:30-12:00, June 20, 2012
- Place
- Lecture Room
- Contents
-
Speaker 1:Ayumu Matsuzawa
M2, SOKENDAI, Mitaka（supervisor : Satoru Iguchi）
Title : Evaluation of pointing error on ALMA ACA antennaSpeaker 2： Nagisa Shino
D1, SOKENDAI, Mitaka（supervisor : Mareki Honma）
Title : Testing the formation scenario of massive star by CH3OH maser - Organizer
- Name : Nagisa Shino
- Comment
- TV conference system is available connecting from Nobeyama, Hawaii, Mizusawa, and Okayama
- キャンパス
- 三鷹
- セミナー名
- VLBIコロキウム
- 臨時・定例の別
- 定例 (毎週水曜日の下記の時間)
- 日時
- 6月20日（水）15:00～16:00
- 場所
- 中央棟(南)2階VLBIセミナー室
- 講演者
- 小山友明 所属：水沢VLBI観測所
- タイトル
- “New observing System to support VDIF specifications with 10 GbE for VERA, JVN and KJJVC”
- Abstract
- Japanese real-time VLBI network OCTAVE (Optically Connected Array for VLBI Exploration) has been developed VLBI observation Systems (OCTAVE-Families) to support the VDIF specifications. The Octave systems consist of a high speed 8-Gsps 3-bit ADC (OCTAD) enable us to acquire not only wide intermediate frequency but also radio frequency up to 50 GHz, a converter (OCTAVIA) between one 10 GbE port and four 2 Gbps input and output ports conformable to VSI-H and new recorders (OCTADISK and VSREC) at a rate of 4.5 Gbps and above 8 Gbps and high speed software correlator system (OCTACOR) . These OCTAVE systems are connected with VDIF (Vlbi Data Interchange Format) specifications via 10 GbE network. These components are used for VERA, JVN(Japanese VLBI network) and KJJVC (Korea-Japan Joint VLBI Correlator).
I will report the detailed performances and results of test VLBI observations. - 連絡先
- 名前：秋山和徳 (志野渚)
- 備考
- テレビ参加：可能
6月22日(金)
- キャンパス
- 三鷹
- セミナー名
- VLBIコロキウム
- 臨時・定例の別
- 臨時 (毎週水曜日の下記の時間)
- 日時
- 6月22日（金）15:00～16:00
- 場所
- 中央棟(南)2階VLBIセミナー室
- 講演者
- 服部公平 所属：東大 天文センター D2
- タイトル
- Rotational Behavior of Halo Blue Horizontal Branch Stars in the Milky Way
- Abstract
- The stellar halo of the Milky Way (MW) contains a lot of information on the formation and evolution the MW itself, since it consists of oldest stars in the MW and its approximate collisionless nature has conserved the kinematic properties.
Recently, Carollo et al. (2010) study the kinematics of one of the largest set of nearby halo stars from SDSS Data Release 7.
Based on their decomposition analysis, they find that the stellar halo consists of at least two components (inner and outer halo) with different kinematic and chemical properties as follows:
(1) The inner halo consists of metal-rich stars (<[Fe/H]> ~ -1.6) which show no net rotation (V_phi = 0 km/s) with respect to the Galactic center;
(2) The outer halo consists of metal-poor stars (<[Fe/H]> ~ -2.2) which show significantly retrograde rotation (V_phi = -80 km/s).
They expect that inner halo originates from a chaotic major merger at the last stage of formation of proto-galactic clump, while outer halo form via accretion and disruption of smaller stellar systems such as dwarf galaxies or globular clusters.
Interestingly, an increasing number of cosmological simulations of MW-sized galaxies support Carollo et al.’s result that metal-poor halo stars tend to rotate more slowly than metal-rich stars do (e.g. McCarthy et al. 2012).
However, we have to note that Carollo et al.’s result might be affected by observational errors, since their sample stars rely on the ground-based proper-motion data, which are not as accurate as line-of-sight velocity data (e.g., Schonrich et al. 2011).
In this presentation, I will talk about another method to derive the rotational behavior of halo stars in the Milky Way, based on line-of-sight velocity alone (i.e., without using proper-motion).
We use ~2,500 Blue Horizontal Branch (BHB) stars from SDSS Data Release 8 and find that metal-poor BHB stars rotates significantly slower than metal-rich BHB stars, which supports the Carollo et al.’s results.
We also find that mean rotational velocity of BHB stars decreases as a function of Galactocentric distance, which is similar to the result of Chiba & Beers (2000) who study the orbital motion of nearby halo stars.
I will discuss the physical interpretation of these data. - 連絡先
- 名前：秋山和徳 (志野渚)
- 備考
- テレビ参加：可能
以上