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Comet 67P/Churyumov-Gerasimenko, location of pristine material?
Kossacki, Konrad J.
This work is intended to answer the question, whether on comet 67P/Churyumov-Gerasimenko pristine, not hardened material can be locally preserved close to the surface. Simulated is the thermally driven sintering of ice-dust grains underlying the dust mantle. Considered is the Ma'at region located at the north side of the small lobe Head. It is sho…
Consistency relation and non-Gaussianity in a Galileon inflation
Asadi, Kosar; Nozari, Kourosh
We study a particular Galileon inflation in the light of Planck2015 observational data in order to constraint the model parameter space. We study the spectrum of the primordial modes of the density perturbations by expanding the action up to the second order in perturbations. Then we pursue by expanding the action up to the third order and find th…
Tomographic Separation of Composite Spectra. XII. The Physical Properties and Spectral Phase Variability of the Massive Close Binary HD 159176
Penny, Laura R.; Epps, Jacob G.; Snyder, Joseph D.
We present our analysis of the double-lined, O-binary HD 159176 based on observations made with the International Ultraviolet Explorer (IUE). We use cross-correlation methods to obtain radial velocities, confirm the orbital elements, and estimate the UV flux ratio. In addition, we cross-correlate specific regions of the IUE spectra corresponding t…
Editorial of the special issue - "Rosetta and Philae at comet 67P/Churyumov-Gerasimenko"
Taylor, Matthew G. G. T.; Ulamec, Stephan
Giotto, the first european/ESA - interplanetary space probe had not flown by Halley's comet, yet, when the first plans for the next mission to investigate a comet were being made. back in 1984, Rosetta became part of ESAs horizon 2000 programme, originally envisioned as a comet nucleus sample return mission.
Scattering of hydrogen, nitrogen and water ions from micro pore optic plates for application in spaceborne plasma instrumentation
Barabash, Stas; Wieser, Martin; Stude, Joan
Time-of-flight mass spectrometers for upcoming space missions into enhanced radiation environments need to be small, light weight and energy efficient. Time-of-flight systems using surface interactions as start-event generation can be smaller than foil-type instruments. Start surfaces for such applications need to provide narrow angular scattering…
Diagnosing transient plasma status: from solar atmosphere to tokamak divertor
Doyle, J. G.; Summers, H. P.; Giunta, A. S. +3 more
This work strongly exploits the interdisciplinary links between astrophysical (such as the solar upper atmosphere) and laboratory plasmas (such as tokamak devices) by sharing the development of a common modelling for time-dependent ionisation. This is applied to the interpretation of solar flare data observed by the UVSP (Ultraviolet Spectrometer …
Inverse scattering problem in turbulent magnetic fluctuations
Narita, Yasuhito; Baumjohann, Wolfgang; Treumann, Rudolf A.
We apply a particular form of the inverse scattering theory to turbulent magnetic fluctuations in a plasma. In the present note we develop the theory, formulate the magnetic fluctuation problem in terms of its electrodynamic turbulent response function, and reduce it to the solution of a special form of the famous Gelfand-Levitan-Marchenko equatio…
An objective classification of Saturn cloud features from Cassini ISS images
Del Genio, Anthony D.; Barbara, John M.
A k-means clustering algorithm is applied to Cassini Imaging Science Subsystem continuum and methane band images of Saturn's northern hemisphere to objectively classify regional albedo features and aid in their dynamical interpretation. The procedure is based on a technique applied previously to visible-infrared images of Earth. It provides a new …
Probing the interstellar dust in galaxies over >10 Gyr of cosmic history
York, Donald G.; Kulkarni, Varsha P.; Welty, Daniel E. +3 more
Dust has a profound effect on the physics and chemistry of the interstellar gas in galaxies and on the appearance of galaxies. Understanding the cosmic evolution of dust with time is therefore crucial for understanding the evolution of galaxies. Despite the importance of interstellar dust, very little is known about its nature and composition in d…
Suzaku observations of two diffuse hard X-ray source regions, G22.0+0.0 and G23.5+0.1
Bamba, Aya; Yamauchi, Shigeo; Sumita, Mayu
G22.0+0.0 and G23.5+0.1 are diffuse hard X-ray sources discovered in the ASCA Galactic Plane Survey. We present Suzaku results of spectral analysis for these sources. G22.0+0.0 is confirmed to be a largely extended emission. Its spectra were represented by a highly absorbed power-law model with a photon index of 1.7 ± 0.3 and a moderately absorbed…