Institution
Japan Aerospace Exploration Agency
Facility•Tokyo, Japan•
About: Japan Aerospace Exploration Agency is a facility organization based out in Tokyo, Japan. It is known for research contribution in the topics: Galaxy & Telescope. The organization has 4327 authors who have published 12054 publications receiving 208330 citations.
Papers published on a yearly basis
Papers
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TL;DR: In this article, the authors presented H2O maser data from a survey toward IRAS sources in the Galaxy with the Nobeyama 45 in telescope, which carried out a total of 2229 observations toward 1563 sources and detected water-maser emission toward 222 sources.
Abstract: We present H2O maser data from a survey toward IRAS sources in the Galaxy with the Nobeyama 45 in telescope. This survey had a 1 sigma noise level as small as 0.24 Jy, resulting in one of the most sensitive water-maser surveys. The maximum distance of the masers to be detected by our survey is estimated to be 3 kpc for sources with F-nu,F-1kpc = 100 Jy, our survey could detect all sources in the Galaxy. We carried out a total of 2229 observations toward 1563 sources and detected water-maser emission toward 222 sources. Our survey newly found masers from 75 of the 222 sources. The maser spectra of the new sources are shown in addition to the line parameters of all the detected sources. Furthermore, we discovered an extremely high-velocity component with V-LSR, = -146 km s(-1) toward a well-known source, NGC 7538 IRS 11. For the three sources of NGC 1333 IRAS 4A/B, IRAS 05329-0512, and 06053-0622, we succeeded to spatially separate multiple-velocity components.
77 citations
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Max Planck Society1, Intelligence and National Security Alliance2, European Space Research and Technology Centre3, Centre national de la recherche scientifique4, Spanish National Research Council5, California Institute of Technology6, Chalmers University of Technology7, University of Liège8, Goddard Space Flight Center9, Nagoya University10, Kapteyn Astronomical Institute11, Schiller International University12, Open University13, Complutense University of Madrid14, Japan Aerospace Exploration Agency15, Stockholm University16, Rutherford Appleton Laboratory17
TL;DR: The first far-IR observations of the solar-type stars delta Pav, HR 8501, 51 Peg, and zeta(2) Ret were made by as discussed by the authors, using PACS and SPIRE instruments with the objective of studying infrared excesses due to exo-Kuiper belts around nearby solar type stars.
Abstract: We present the first far-IR observations of the solar-type stars delta Pav, HR 8501, 51 Peg and zeta(2) Ret, taken within the context of the DUNES Herschel open time key programme (OTKP). This project uses the PACS and SPIRE instruments with the objective of studying infrared excesses due to exo-Kuiper belts around nearby solar-type stars. The observed 100 mu m fluxes from delta Pav, HR 8501, and 51 Peg agree with the predicted photospheric fluxes, excluding debris disks brighter than L-dust/L-star similar to 5 x 10(-7) (1 sigma level) around those stars. A flattened, disk-like structure with a semi-major axis of similar to 100 AU in size is detected around zeta(2) Ret. The resolved structure suggests the presence of an eccentric dust ring, which we interpret as an exo-Kuiper belt with L-dust/L-star approximate to 10(-5).
77 citations
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TL;DR: In this paper, a new numerical software package to analyze spacecraft charging, named ldquomulti-utility spacecraft charging analysis toolrdquo (MUSCAT), has been developed.
Abstract: A new numerical software package to analyze spacecraft charging, named ldquomulti-utility spacecraft charging analysis toolrdquo (MUSCAT), has been developed. MUSCAT consists of an integrated graphical user interface tool called ldquoVineyardrdquo and the solver. Vineyard enables satellite engineers to compute spacecraft charging with little knowledge of the numerical calculations. Functions include 3-D satellite modeling, parameter input such as material and orbit environment, data transfer, and visualization of numerical results. Fundamental physical processes of charged-particle-surface interaction are included in the solver. These functions enable MUSCAT to analyze spacecraft charging at geostationary orbit, low Earth orbit, and polar Earth orbit (PEO). The numerical solver code is parallelized for high-speed computation, and the algorithm is optimized to achieve analysis of large-scale PEO satellite in the design phase. Variable time steps are also used to calculate the rapid change of the spacecraft body potential and the gradual change of the differential voltage in a single simulation with a practical number of iterations. In this paper, the functionality, algorithms, and simulation examples of MUSCAT are presented.
77 citations
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TL;DR: The authors show that using explicit representation of cloud microphysics, in global scale modelling, rather than parameterisations, reduces the overestimation of aerosol effect on cloud properties.
Abstract: Aerosols affect climate by modifying cloud properties through their role as cloud condensation nuclei or ice nuclei, called aerosol–cloud interactions. In most global climate models (GCMs), the aerosol–cloud interactions are represented by empirical parameterisations, in which the mass of cloud liquid water (LWP) is assumed to increase monotonically with increasing aerosol loading. Recent satellite observations, however, have yielded contradictory results: LWP can decrease with increasing aerosol loading. This difference implies that GCMs overestimate the aerosol effect, but the reasons for the difference are not obvious. Here, we reproduce satellite-observed LWP responses using a global simulation with explicit representations of cloud microphysics, instead of the parameterisations. Our analyses reveal that the decrease in LWP originates from the response of evaporation and condensation processes to aerosol perturbations, which are not represented in GCMs. The explicit representation of cloud microphysics in global scale modelling reduces the uncertainty of climate prediction. Most global climate models overestimate the aerosol effect on cloud properties, but the reason for this is unclear. Here the authors show that using explicit representation of cloud microphysics, in global scale modelling, rather than parameterisations, reduces the overestimation.
77 citations
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National Institutes of Natural Sciences, Japan1, Graduate University for Advanced Studies2, University of Tsukuba3, Nagoya University4, Kagoshima University5, Joetsu University of Education6, Meisei University7, University of Tokyo8, Japan Aerospace Exploration Agency9, Yamaguchi University10, Osaka Prefecture University11, Kwansei Gakuin University12, Saitama University13, University of Nigeria, Nsukka14
TL;DR: The FOREST Unbiased Galactic plane Imaging Survey (FUGIN) as discussed by the authors was the first project to investigate the distribution, kinematics, and physical properties of both diffuse and dense molecular gas in the Galaxy at once by observing 12CO, 13CO, and C18O J=1-0 lines simultaneously.
Abstract: The FOREST Unbiased Galactic plane Imaging survey with the Nobeyama 45-m telescope (FUGIN) project is one of the legacy projects using the new multi-beam FOREST receiver installed on the Nobeyama 45-m telescope. This project aims to investigate the distribution, kinematics, and physical properties of both diffuse and dense molecular gas in the Galaxy at once by observing 12CO, 13CO, and C18O J=1-0 lines simultaneously. The mapping regions are a part of the 1st quadrant (10d < l < 50d, |b| < 1d) and the 3rd quadrant (198d < l <236d, |b| < 1d) of the Galaxy, where spiral arms, bar structure, and the molecular gas ring are included. This survey achieves the highest angular resolution to date (~20") for the Galactic plane survey in the CO J=1-0 lines, which makes it possible to find dense clumps located farther away than the previous surveys. FUGIN will provide us with an invaluable dataset for investigating the physics of the galactic interstellar medium (ISM), particularly the evolution of interstellar gas covering galactic scale structures to the internal structures of giant molecular clouds, such as small filament/clump/core. We present an overview of the FUGIN project, observation plan, and initial results, which reveal wide-field and detailed structures of molecular clouds, such as entangled filaments that have not been obvious in previous surveys, and large-scale kinematics of molecular gas such as spiral arms.
77 citations
Authors
Showing all 4340 results
Name | H-index | Papers | Citations |
---|---|---|---|
Yasushi Fukazawa | 135 | 882 | 64424 |
Jun Kataoka | 121 | 603 | 54274 |
Tadayuki Takahashi | 112 | 932 | 57501 |
Takaaki Tanaka | 105 | 321 | 41804 |
Yasunobu Uchiyama | 105 | 373 | 39610 |
Satoshi Tanaka | 96 | 739 | 76264 |
Masashi Hazumi | 87 | 708 | 29603 |
K. Izumi | 84 | 229 | 53205 |
Carolus J. Schrijver | 81 | 297 | 29858 |
Satoru Takahashi | 79 | 589 | 28007 |
Chris Done | 79 | 457 | 23210 |
Yasuo Doi | 79 | 370 | 33445 |
Poshak Gandhi | 75 | 481 | 18419 |
Alan M. Title | 74 | 203 | 21923 |
Yoshihiro Ueda | 72 | 576 | 25787 |