宇宙科学談話会

ISAS Space Science Colloquium & Space Science Seminar

FY2018

ENGLISH

宇宙実験・地上実験から探る地球外有機物と生命の起源
Search for Origins of Extraterrestrial Organics and Life by Ground and Space Experiments

小林 憲正 (Kensei KOBAYASHI)
横浜国立大学大学院工学研究院(YOKOHAMA National University)

As a possible origin of the life on the earth, the importance of extra- terrestrial materials has been pointed out. In this talk, I will outline the research activities on the formation, denaturation, and transportation to the earth of organic materials under the space environments outside the earth, and will discuss their possible links the origin of the lief on the earth.

Place: 2F Conf. room(1236) / 研究管理棟2階会議場(1236号室)

ENGLISH

Lean Satellite, a new way of making and using satellites

趙 孟佑(Mengu CHO)
九州工業大学大学院工学研究院(Kyushu Institute of Technology)

In recent years, development and utilization of small/micron/nano/pico satellites are proliferating worldwide.
There is a trend to call those satellites as "lean satellite" to describe the non-traditional development and management methodology and philosophy to deliver the satellite value at low cost and in short time more correctly rather than defining the satellites by mass and/or size. One big problem of lean satellite is how to assure mission success while seeking low cost and fast-delivery.
Center for nanosatellite testing at Kyushu Institute of Technology (Kyutech) worked on testing of various satellites from Japan and abroad. It also led the effort of nanosatellite environment testing standard, ISO-19683. Kyutech also developed and launched more than 12 satellites. From those experiences, solutions to the problem have started to appear. The latest trend of lean satellite will be also presented.

Place: 2F Conf. room(1236) / 研究管理棟2階会議場(1236号室)

日本語

博士課程在籍者のキャリアパス等に関する意識調査; フォーカス・グループ・インタビューからの考察(仮題)

松澤 孝明(まつざわ たかあき)
文部科学省科学技術・学術政策研究所

属性の異なる大学の博士課程籍者を対象に対し、博士課程への進学動機や、キャリアパスに関する不安、就職観や専門観ついて、市場調査の方法のひとつであるフォーカス・グループ・インタビュー(FGI)によるインタビュー調査を行った。その結果、我が国の博士課程在籍者には共通する思考パターンやノーム(規範)が観察されたので、博士人材のキャリアパスの多様化と雇用適正の観点から考察を行い、いくつかのモデルの検討を行った。 (担当小林より)博士課程の本音に迫る調査結果をご紹介いただけることになりました。学生の皆さんはご自身の将来の参考に、先生方はいよいよ到来する「2018年問題」に備えて、必聴です!

Place: Shin-A 2F Conf. room A (1257) / 新A棟2階会議室A(1257号室)
※通常と曜日が異なりますので、ご注意ください。

ENGLISH

Space gravitational wave antenna DECIGO and B-DECIGO

川村 静児(Seiji KAWAMURA)
名古屋大学大学院理学研究科(NAGOYA University)

DECi-hertz Interferometer Gravitational-wave Observatory (DECIGO) is a future Japanese space gravitational-wave antenna. The most important objective of DECIGO is to detect gravitational waves coming from the inflation of the universe. DECIGO consists of four clusters of spacecraft, and each cluster consists of three spacecraft with three Fabry-Perot Michelson interferometers. As a pathfinder mission of DECIGO, B-DECIGO should be launched to demonstrate technologies necessary for DECIGO as well as to lead to fruitful multimessenger astronomy. B-DECIGO is a small-scale version of DECIGO with the sensitivity good enough to provide frequent detection of gravitational waves. In this talk, the aimed science and the mechanical and optical design of DECIGO and B-DECIGO will be explained in details.

Place: Shin-A 2F Conf. room A (1257) / 新A棟2階会議室A(1257号室)

ENGLISH

水素分子の形成とオルトーパラ転換 ― 宇宙科学との関係を考える
Molecular-hydrogen generation and ortho-para conversion - Relation with astrophysics

福谷 克之(Katsuyuki FUKUTANI)
東京大学 生産技術研究所(Institute of Industrial Science, The University of Tokyo)

Hydrogen is the most abundant element in the universe and a main constituent of the interstellar media. Recombinative formation of molecular hydrogen from atomic hydrogen leads to molecular clouds, which is regarded as a precursor state of star formation. Molecular hydrogen exists in nuclear-spin isomers designated as ortho and para species according to the total nuclear spin of 1 and 0, respectively. Whereas the transition between the ortho and para species and molecular hydrogen formation are extremely slow in gas phase, both processes are promoted through interaction with solid surfaces. In recent years, the ortho-para ratio of molecular hydrogen in space and planetary environments has been experimentally observed by infrared satellite observatory, which often reveals deviation from the molecular-cloud temperature. This is expected to provide us with information on evolution of molecular clouds and star formation. In these regards, we experimentally investigate molecular-hydrogen formation and ortho-para conversion on solid surfaces in the laboratory, and discuss the physical mechanism.

Place: 2F Conf. room(1236) / 研究管理棟2階会議場(1236号室)

日本語

非平衡プラズマ研究のための鉄イオン原子データ・分光モデルの研究

村上 泉
核融合科学研究所 ヘルカリ研究部

非平衡プラズマ現象の研究に向けた、極端紫外スペクトル線解析のための鉄イオンの原子データと分光モデルの評価を、大型ヘリカル装置(LHD)等実験室プラズマを用いて行った。Fe XVIIの発光線強度比の評価から、ひのでEISの計測値の理論値・実験値からの ずれはEISの感度較正の経年変化の発見へとつながった。精度を評価した原子データ・分光モデルにより、様々な非平衡プラズマ現象研究への応用が期待できる。

Place: 2F Conf. room(1236) / 研究管理棟2階会議場(1236号室)

日本語

宇宙生命計算科学連携拠点と研究成果

梅村 雅之
筑波大学 計算科学研究センター

この10数年、星間分子観測、系外惑星観測、アストロバイオロジーの様々な取り組みにより、宇宙における生命起源探究の機運が急速に高まってきている。本拠点では、宇宙における生命の起源に関わるキープロセスを計算科学の手法により探究し、宇宙生命科学のブレークスルーを目指している。本講演では、宇宙生命計算科学連携拠点の概要と、星間分子生成や微惑星形成などに関する最新の研究成果について紹介する。

Place: 2F Conf. room(1236) / 研究管理棟2階会議場(1236号室)

日本語

月のプラズマ・電磁環境研究の現状

西野 真木
名古屋大学 宇宙地球環境研究所

月のプラズマ・電磁環境研究の最新の話題を紹介する。月は濃厚な大気や固有磁場を持たず、固体天体表面と周囲の宇宙プラズマが直接的に相互作用をする。また、月表面の一部には磁気異常が存在し、それらと宇宙プラズマの相互作用も理解が進みつつある。本講演では、月周回衛星「かぐや」や同時代の探査機による主な科学成果を振り返るとともに、未解決問題を提示する。

Place: 2F Conf. room(1236) / 研究管理棟2階会議場(1236号室)

ENGLISH

Exploring the Dusty and Dynamic IR Sky with Spitzer, JWST, and Beyond

Ryan Lau
ISAS/JAXA

I will discuss results from our mid-IR transient survey with the Spitzer Space Telescope and our future plans with the upcoming James Webb Space Telescope (JWST) in exploring the dusty and dynamic behavior of massive stars.

Place: 2F Conf. room(1236) / 研究管理棟2階会議場(1236号室)

日本語

将来的な宇宙輸送システムの選択肢としての宇宙エレベーター

佐藤 実
東海大学 清水教養教育センター

宇宙エレベーターは、地表から宇宙空間までのばしたケーブルをたどって人や物を運ぶ宇宙輸送システムの構想である。クライマーと呼ばれるケーブル上を移動する昇降機をもちいる構想であることから、レール上を移動する列車になぞられて、宇宙列車とよばれることもある。ロケット推進によらずに地表と宇宙空間を往き来することから、既存の宇宙輸送系とは異なる特徴をもち、将来の宇宙輸送インフラの一翼をになう潜在的な可能性をもつ。しかし、ケーブルの素材としての強さと軽さをもつ材料がないことをはじめ、工学的、社会的な問題があり、短期的な実現はむずかしい。宇宙エレベーター実現に向けた課題と現在の動向について紹介する。

Place: 2F Conf. room(1236) / 研究管理棟2階会議場(1236号室)

ENGLISH

Calorimetric Electrons Telescope (CALET) on the International Space Station: The latest results from the first three-year observations on orbit

鳥居 祥二(Shoji TORII)
早稲田大学理工学術院 理工学研究所(Waseda University)

The CALorimetric Electron Telescope (CALET) space experiment, which has been developed by Japan in collaboration with Italy and the United States, is a high-energy astroparticle physics mission installed on the International Space Station (ISS). The primary goals of the CALET mission include investigating possible nearby sources of high-energy electrons, studying the details of galactic particle propagation and searching for dark matter signatures. During a mission, extendable to five years, the CALET experiment measures the flux of cosmic- ray electrons (including positrons) to 20 TeV, gamma-rays to 10 TeV and nuclei with Z=1 to 40 up to 1,000 TeV. Since the start of operation in mid-October, 2015, a continuous observation has been kept mainly by triggering high energy (>10 GeV) showers without any major interruption. The number of the triggered events over 10 GeV is nearly 20 million per month. By using the data obtained during the first three-years, we will have a summary of the CALET observations: 1) Electron+Positron energy spectrum, 2) Proton and Nuclei spectrum, 3) Gamma-ray observation, with results of the performance study on orbit. We also present the results of observations of the electromagnetic counterparts to LIGO-VIRGO gravitational wave events and high-energy counterparts to GRB events measured with the CALET Gamma-ray Burst Monitor (CGBM).

Place: 2F Conf. room(1236) / 研究管理棟2階会議場(1236号室)

日本語

「あらせ」によるジオスペース探査の最新成果

三好 由純
名古屋大学 宇宙地球環境研究所

イプシロンロケット2号機によりジオスペース探査衛星「あらせ」が2016年12月に打ち上げられてから1年半が経った。その間には大規模な太陽フレアに伴う宇宙嵐の発生から終息まで一連の貴重な科学データの取得や、衛星と地上観測の連携による脈動オーロラの発生メカニズムの解明に成功した。本講演では「あらせ」がこれまでに取得した最新の科学成果について紹介する。

Place: 2F Conf. room(1236) / 研究管理棟2階会議場(1236号室)

※通常と曜日が異なりますので、ご注意ください。

ENGLISH

Quantum Chemistry Approaches to Elucidate Chemical Reactions in Astrobiology

庄司 光男(Mitsuo SHOJI)
筑波大学計算科学研究センター(Center for Computational Sciences, Tsukuba Univ.)

Variety of chemical reactions occur in interstellar space. These reactions are different to the familiar reactions performed under biological and ordinal thermal conditions. Therefore, theoretical approaches to elucidate such reactions are not yet established and the astrobiology is exciting and challenging research region for computational chemistry. In my presentation, a novel approach to search chemical reactions, called GLAS method, is discussed. Our GLAS method is significantly valuable for searching chemical reactions. Glycine formation reactions, which deeply relate to the origin of life, and a molecular mechanism of chiral amplitude in comet are discussed.

Place: 2F Conf. room(1236) / 研究管理棟2階会議場(1236号室)

ENGLISH

High efficiency superconducting nanowire single photon detectors in NICT, for deep space optical communication

三木 茂人Shigehito MIKI)
国立研究開発法人情報通信研究機構(NICT)

We introduce superconducting nanowire single photon detection technology with ~80 % detection efficiency at from visible to near infrared wavelength region for applications of deep space optical communication.

Place: Nyusatsu Conf.room(1134) / 研究管理棟1階入札会議室(1134号室)

ENGLISH

Searching for Planets like Earth around Late-M Dwarfs using Subaru/IRD

佐藤 文衛(Bunei SATO)
東京工業大学(Tokyo Institute of Technology)

We plan to conduct an extensive, precise near-infrared (NIR) RV survey focused on late-M dwarf stars (LMDs) using newly commissioned InfraRed Doppler (IRD) instrument and Subaru telescope. IRD is an echelle spectrometer that covers the wavelengths from 0.97 to 1.75 m with a high spectral resolution (70,000). IRD's high instrumental stability and its use of a laser frequency comb as a very precise wavelength reference allow us to measure the RVs of LMDs with a precision of 2 m/s or better.
The goals of our survey are: (1) to discover small rocky planets in the habitable zone around these low-mass stars, and (2) to uncover the distribution of planetary systems containing Earth-mass planets and more massive planets. We here outline our planet search project and also introduce other observations that will be possible using IRD.

Place: Shin-A 2F Conf. room A (1257) / 新A棟2階会議室A(1257号室)

ENGLISH

Space Colony Research Center at the Tokyo University of Science ーDeveloping technology for moon-base habitation and its application to the earth societyー

木村 真一(Shinichi KIMURA),向井 千秋(Chiaki MUKAI)
東京理科大学(Tokyo University of Science)

Space exploration stimulates our imaginations and empowers our activities to make our dreams to happen. With hopes future living on the moon-base supported by science and technology, the Tokyo University of Science (TUS) established the Space Colony Research Center last year, funded by the Private University Research Branding Project of the Ministry of Education, Culture, Sports, Science and Technology (MEXT).
The center interdisciplinary works amongst in-house researchers as well as outside academia with the collaboration of government and industry.
The goal of the Center is to further improve technology in areas the TUS excels at, making the technology viable in space and creating a virtuous cycle of technological innovation on Earth as well. It is comprised of four teams: 1) The Space Agriculture Team, researching hydroponics to grow food in space; 2) The Energy Creation and Storage Technology Team, researching the generation of energy necessary to support life in space; 3) The Water and Air Recycling Technology Team, researching how to recycle these limited resources; and 4) The Space system development and Quality of Life Design Team, in charge overall and researching medical and other systems for while living in space. The core of their research is based around photocatalysis and high-efficiency energy generation with a low environmental impact, strengths of the university.
Our plan of the Space Colony Research Center will be discussed. And the concept of the moon-base frontier medicine to ensure safe and productive human activities will be briefly introduced.

Place: 2F Conf. room(1236) / 研究管理棟2階会議場(1236号室)

ENGLISH

Basilisk - Next Generation of Open Spacecraft Simulation and Mission Analysis Tool

Hanspeter Schaub
Univ. of Colorado Boulder

The Basilisk framework is an modular C/C++ based simulation environment that is wrapped with Python to make it scriptable. This allows for dynamics actuators, sensor, and space environment forces to me modeled in an interchangeable manner. This seminar highlights on- going Basilisk related research efforts between the Autonomous Vehicle Systems Lab and the Laboratory of Atmospheric and Space Physics, and how this is changing how mission simulations and autonomous software is being developed.

※通常と曜日が異なりますので、ご注意ください。

Place: 2F Conf. room(1236) / 研究管理棟2階会議場(1236号室)

日本語

超小型衛星打上げ機SS-520 5号機の実験結果について

羽生 宏人(Hiroto HABU)
ISAS/JAXA 宇宙飛翔工学研究系

2018年2月3日にSS-520 5号機を打上げ、超小型衛星TRICOM-1Rの軌道投入実験を行った。ロケットは計画通り飛行し、発射後7分30秒後にTRICOM-1Rを分離して、軌道投入実験は成功した。本研究開発活動は、2015年に採択された経済産業省の委託事業を基礎に所内プロジェクトとして設置された。2017年1月15日に最初の実験としてSS-520 4号機により実行したが、機体の不具合により超小型衛星TRICOM-1の軌道投入に失敗した。実験後の原因究明結果から、不具合の主たる推定原因は電源系のショートであることが判明した。SS-520 5号機実験は、必要な技術対策や改善を施して4号機再実験として実施された。今回は研究開発の技術的な観点のみならず、打上げ現場の実務の様子も合わせて紹介する。

Place: 2F Conf. room(1236) / 研究管理棟2階会議場(1236号室)

ENGLISH

Small Worlds - Big Discoveries

James Green, Chief Scientist
NASA

One of the most important sets of objects in our solar system are small bodies such as asteroids, planetesimals, protoplanets, dwarf planets, and comets. These small worlds provide a wealth of knowledge that, if properly understood, can tell us an enormous amount about the origin and evolution of the solar system. They represent remnants of the building blocks of the planets and provide insight into the conditions of our earliest history. It is also well known that after the formation of the solar system continual impacts by small bodies to the terrestrial planets were the delivery mechanism of key elements that perhaps gave rise to the origin of life here on Earth. Small bodies also experience a myriad of processes, providing numerous natural science laboratories to gain knowledge into the evolution of the solar system. In addition, small bodies represent both hazards, such as Near Earth Objects, but also potential future resources, as humans leave low Earth orbit and trek out into the solar system their need for future materials and fuels may largely be met by mining certain types of small bodies.

This talk will place the current small worlds missions, mostly by JAXA and NASA, into a broader context of the importance small bodies plays in the solar system and what they are telling us. This is truly an exciting time for exploring these small worlds allowing true missions of discovery. We have much to learn from them.

通常と曜日・時間が異なりますので、ご注意ください。

Place: 2F Conf. room(1236) / 研究管理棟2階会議場(1236号室)

ENGLISH

Astrochemical Approach to Star and Planet Formation

坂井 南美(Nami SAKAI)
理化学研究所(RIKEN)

Star and planet formation is one of the most fundamental structure-formation processes in the Universe. Physical processes of star and planet formation have widely been investigated as one of the major targets of astronomy and astrophysics by observations in the entire wavelength region during the last few decades. Although a rough outline of these processes has been presented, there still remain many unknowns and missing links. One of them is when the disk structure is formed around a protostar, and how it is evolved into a protoplanetary disk and eventually to a planetary system. At the same time, understanding the evolution of matter from interstellar clouds to stars and planets is also a goal of astronomy. So far, about 200 interstellar molecules have been identified mainly by radio-astronomical observations. This indicates the high chemical complexity of interstellar clouds even in the extreme condition of low temperature (10-100 K) and low density (102-107 cm-3), which would ultimately be related to an origin of rich substances in the Solar System. Thus, approaches both from physical and chemical view points are indispensable to bridge star/planet formation studies and planetary science of the Solar System. In this talk, I am going to present importance of chemistry in astronomical studies by introducing some observational results.

星の形成は宇宙における最も基本的な構造形成過程であるとともに、星間物質か ら惑星系物質への物質進化の場でもある。したがって、「太陽系のような環境がどれほど宇宙で普遍的に存在するのか?」この究極の問いに答えるためには、物理進化・化学進化の両面から研究展開することが重要である。本講演では、アルマ望遠鏡の観測結果をもとに、そのようなアプローチによる研究成果について紹介する。

Place: 2F Conf. room(1236) / 研究管理棟2階会議場(1236号室)

ENGLISH

NASA's Neutron star Interior Composition Explorer (NICER) mission

榎戸 輝揚(Teruaki ENOTO
京都大学理学研究科(Kyoto UNIVERSITY)

I will present an overview of the NASA's Neutron star Interior Composition Explorer (NICER) mission which was installed aboard the International Space Station in June 2017. NICER provides high-precision timing measurements of neutron stars, objects containing ultra-dense matter at the threshold of collapse into black holes.

※通常と曜日が異なりますので、ご注意ください。

Place: 2F Conf. room(1236) / 研究管理棟2階会議場(1236号室)

ENGLISH

Multi-messenger observations of gravitational wave sources

田中 雅臣(Masaomi TANAKA
東北大学大学院 理学研究科 (TOHOKU UNIVERSITY)

On 17th August 2017, the first gravitational wave (GW) detection from a neutron star merger (GW170817) was achieved. The detection triggered electromagnetic (EM) wave observations over the entire wavelength range, which marked the beginning of a new era of "multi-messenger" astronomy. In this seminar, I briefly review multi-messenger observations of GW170817 and show results of optical and near-infrared observations of the EM counterpart. The observed properties of optical and near-infrared emission are similar to those of theoretically-expected "kilonova", which is powered by radioactive decays of r-process nuclei. I discuss implications for the origin of heavy elements in the Universe.

史上初めて検出された中性子星合体からの重力波イベント(GW170817)は広い波長域の電磁波でも観測され、本格的なマルチメッセンジャー天文学が幕を開けました。談話会では、重力波天体のマルチメッセンジャー観測を概観し、理解が進みつつある宇宙の重元素の起源についてお話しします。

Place: 2F Conf. room(1236) / 研究管理棟2階会議場(1236号室)

ENGLISH

ESA Planck Mission

Jan Tauber
ESA

This talk will present an overview of the Planck mission, including a brief outline of its development and of some of the challenges that it presented. I will then review the most recent Planck data and results, with emphasis on polarization. The use of CMB polarization data from Planck confirms the best-fit Lambda-CDM model obtained with Planck temperature-only data, and improves the accuracy with which cosmological parameters are determined. The most recent results based on polarized E- mode and B-mode CMB power spectra at large angular scales have significant implications on our understanding of the epoch of reionization and primordial gravitational waves. If there is time, I will also present some of the latest analysis of polarized diffuse galactic foreground emissions based on Planck data. Both the synchrotron and dust emission maps obtained from Planck reveal new facets of the galactic interstellar medium.

Place: 2F Conf. room(1236) / 研究管理棟2階会議場(1236号室)

日本語

「ひさき」が明らかにした木星圏物理学とJUICEへの展望

木村 智樹
東北大学

世界初の惑星専用宇宙望遠鏡である「ひさき」がトリガした国際連携に焦点を当 て、木星圏物理学の研究成果を紹介する。また、これらの成果から得られた知見 や経験に基づき、木星氷衛星探査JUICEが担うべき科学の将来展望についても議論 する。

Place: Shin-A 2F Conf. room A (1257) / 新A棟2階会議室A(1257号室)

ENGLISH

Chandra X-Ray Kinematics Study of Young Supernova Remnants

Sangwook Park
University of Texas at Arlington

Supernova remnants are an excellent laboratory to study fundamental subjects of modern astronomy and astrophysics such as stellar evolution and explosion. Realizing the 3-dimensional structure of supernova explosions is critical to understand the explosion physics and the nature of the exploded star. Based on the high resolution grating spectroscopy of Chandra X-ray Observatory, we can perform X-ray kinematic studies of metal-rich stellar debris of supernova explosions to address their 3-D nature. We briefly discuss such kinematic studies of supernova remnants, including our on-going studies of historical events: stellar explosions eye-witnessed in 1987, 1604, and 1572.

Place: 2F Conf. room(1236) / 研究管理棟2階会議場(1236号室)

ENGLISH

Precise and fast computation of gravitational field of general finite body and its application to gravitational study of small asteroids, small satellites, and comets

福島 登志夫(Toshio FUKUSHIMA)
国立天文台(NAOJ)

In order to obtain the gravitational field of a general finite body inside its Brillouin sphere, we developed a new method to compute the field accurately. First, the body is assumed to consist of some layers in a certain spherical polar coordinate system and the volume mass density of each layer is expanded as a Maclaurin series of the radial coordinate. Second, the line integral with respect to the radial coordinate is analytically evaluated in a closed form. Third, the resulting surface integrals are numerically integrated by the split quadrature method using the double exponential rule. Finally, the associated gravitational acceleration vector is obtained by numerically differentiating the numerically integrated potential. Numerical experiments confirmed that the new method is capable of computing the gravitational field independently of the location of the evaluation point, namely whether inside, on the surface of, or outside the body. Also, it can provide sufficiently precise field values, say of 14--15 digits for the potential and of 9--10 digits for the acceleration, respectively. Furthermore, its computational efficiency is better than that of the polyhedron approximation. This is because the computational error of the new method decreases much faster than that of the polyhedron models when the number of required transcendental function calls increases.
As an application, we obtained the gravitational field of 433 Eros from its shape model expressed as the 24x24 spherical harmonic expansion by assuming the homogeneity of the object. The developed formulation would be easily applied to the Ryugu once its surface function is roughly estimated and/or precisely determined.
参考文献:
T. Fukushima 2017, Astron. J., 154:145

エロスやイトカワのような任意形状の天体の重力場を計算する新しい方法を開発した。計算精度と計算速度の両面で、従来の多面体(polyhedron)モデルを上回るばかりでなく、非一様な密度分布の場合にも適用可能である。

Place: Shin-A 2F Conf. room A(1257) / 新A棟2階会議室A(1257号室)