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
More filters
••
TL;DR: The pressure sensitive paint (PSP) technique has potential as a powerful diagnostic tool for measurements in the high Knudsen number regime because it is based on luminescence of molecules as discussed by the authors.
Abstract: The pressure-sensitive paint (PSP) technique has potential as a powerful diagnostic tool for measurements in the high Knudsen number regime because it is based on luminescence of molecules. Three types of PSP [two composed of organic dye and polymer (luminophore/binder), platinum octaethylporphyrin (PtOEP)/silicone polymer (GP197) and platinumtetrakis (pentafluorophenyl) porphyrin (PtTFPP)/poly[1-(trimethylsilyl)-propyne] [poly(TMSP)], and the other ruthenium II tris (4,7-diphenyl-1, 10-phenanthrolin chloride (Bath-Ru) adsorbed on anodized aluminum] are applied to the rarefied gas flow mainly lower than 150 Pa (about 1 torr) to examine fundamental properties, such as pressure/temperature sensitivity, time response of luminescence, and so on
54 citations
••
TL;DR: The hard X-ray detector (HXD) aboard the Xray satellite Suzaku is designed to have a good timing capability with a 61 � s time resolution as mentioned in this paper, and the results were achieved mainly through observations of the Crab pulsar, including simultaneous ones with RXTE, INTEGRAL, and Swift.
Abstract: The hard X-ray detector (HXD) aboard the X-ray satellite Suzaku is designed to have a good timing capability with a 61 � s time resolution. In addition to detailed descriptions of the HXD timing system, results of in-orbit timing calibration and the performance of the HXD are summarized. The relative accuracy of time measurements of the HXD event was confirmed to have an accuracy of 1:9 � 10 � 9 ss � 1 per day, and the absolute timing was confirmed to be accurate to 360 � s or better. The results were achieved mainly through observations of the Crab pulsar, including simultaneous ones with RXTE, INTEGRAL, and Swift.
54 citations
••
TL;DR: The past and recent approaches in space data analysis for the determination of a structure’s dimensionality and the building of D-based coordinate system and a proper moving frame are reviewed to provide a comprehensive understanding of these analysis tools.
Abstract: In the analysis of in-situ space plasma and field data, an establishment of the coordinate system and the frame of reference, helps us greatly simplify a given problem and provides the framework that enables a clear understanding of physical processes by ordering the experimental data. For example, one of the most important tasks of space data analysis is to compare the data with simulations and theory, which is facilitated by an appropriate choice of coordinate system and reference frame. While in simulations and theoretical work the establishment of the coordinate system (generally based on the dimensionality or dimension number of the field quantities being studied) and the reference frame (normally moving with the structure of interest) is often straightforward, in space data analysis these are not defined a priori, and need to be deduced from an analysis of the data itself. Although various ways of building a dimensionality-based (D-based) coordinate system (i.e., one that takes account of the dimensionality, e.g., 1-D, 2-D, or 3-D, of the observed system/field), and a reference frame moving along with the structure have been used in space plasma data analysis for several decades, in recent years some noteworthy approaches have been proposed. In this paper, we will review the past and recent approaches in space data analysis for the determination of a structure’s dimensionality and the building of D-based coordinate system and a proper moving frame, from which one can directly compare with simulations and theory. Along with the determination of such coordinate systems and proper frame, the variant axis/normal of 1-D (or planar) structures, and the invariant axis of 2-D structures are determined and the proper frame velocity for moving structures is found. These are found either directly or indirectly through the definition of dimensionality. We therefore emphasize that the determination of dimensionality of a structure is crucial for choosing the most appropriate analysis approach, and failure to do so might lead to misinterpretation of the data. Ways of building various kinds of coordinate systems and reference frames are summarized and compared here, to provide a comprehensive understanding of these analysis tools. In addition, the method of building these systems and frames is shown not only to be useful in space data analysis, but also may have the potential ability for simulation/laboratory data analysis and some practical applications.
54 citations
••
TL;DR: In this paper, the various effects of meteoroids impacting the Moon are described and results from different detection and study techniques are compared, while the traditional statistics of impact craters allow us to determine the cumulative meteoroid flux on the lunar surface, the recent successful identification of fresh craters in orbital imagery has the potential to directly measure the cratering rate of today.
54 citations
••
TL;DR: In this paper, an analysis with a scanning transmission x-ray microscope (STXM) using X-ray absorption near edge structure (XANES) spectroscopy was applied for the molecular characterization of two kinds of carbonaceous particles of unknown origin, termed category 3, which were collected from the Hayabusa spacecraft sample catcher.
Abstract: Analyses with a scanning transmission x-ray microscope (STXM) using x-ray absorption near edge structure (XANES) spectroscopy were applied for the molecular characterization of two kinds of carbonaceous particles of unknown origin, termed category 3, which were collected from the Hayabusa spacecraft sample catcher. Carbon-XANES spectra of the category 3 particles displayed typical spectral patterns of heterogeneous organic macromolecules; peaks corresponding to aromatic/olefinic carbon, heterocyclic nitrogen and/or nitrile, and carboxyl carbon were all detected. Nitrogen-XANES spectra of the particles showed the presence of N-functional groups such as imine, nitrile, aromatic nitrogen, amide, pyrrole, and amine. An oxygen-XANES spectrum of one of the particles showed a ketone group. Differences in carbon- and nitrogen-XANES spectra of the category 3 particles before and after transmission electron microscopic (TEM) observations were observed, which demonstrates that the carbonaceous materials are electron beam sensitive. Calcium-XANES spectroscopy and elemental contrast mapping identified a calcium carbonate grain from one of the category 3 particles. No fluorine-containing molecular species were detected in fluorine-XANES spectra of the particles. The organic macromolecular features of the category 3 particles were distinct from commercial and/or biological ‘fresh (non-degraded)’ polymers, but the category 3 molecular features could possibly reflect degradation of contaminant polymer materials or polymer materials used on the Hayabusa spacecraft. However, an extraterrestrial origin for these materials cannot currently be ruled out.
54 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 |