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Ion energy distributions and densities in the plume of Enceladus
Omidi, Nojan; Waite, J. Hunter; Cravens, Thomas E. +2 more
Enceladus has a dynamic plume that is emitting gas, including water vapor, and dust. The gas is ionized by solar EUV radiation, charge exchange, and electron impact and extends throughout the inner magnetosphere of Saturn. The charge exchange collisions alter the plasma composition. Ice grains (dust) escape from the vicinity of Enceladus and form …
Rough-Wall Heat Flux Augmentation Analysis Within the ExoMars Project
Gülhan, A.; Neeb, D.; Merrifield, J. A.
The Intragroup versus the Intracluster Medium
Lapi, A.; Cavaliere, A.; Fusco-Femiano, R.
Galaxy groups differ from clusters primarily by way of their lower masses, M ∼ 1014 M ⊙ versus M ∼ 1015 M ⊙. We discuss how mass affects the thermal state of the intracluster or the intragroup medium, specifically as to their entropy levels and radial profiles. We show that entropy is produced in both ca…
A Search for Coronal Activity Among Two Metal-poor Subdwarfs and One Subgiant
Dupree, Andrea K.; Smith, Graeme H.; Günther, Hans Moritz
A search has been made using the XMM-Newton satellite for coronal soft X-ray emission from HD 19445, HD 25329, and HD 140283, three Population II stars in the Galactic halo having metallicities of {{[Fe/H]}}∼ -2. The program stars, consisting of two subdwarfs and one metal-poor subgiant, were pre-selected from ground-based observations to have He …
Development and verification of signal processing system of avalanche photo diode for the active shields onboard ASTRO-H
Yamaoka, K.; Fukazawa, Y.; Kataoka, J. +45 more
The hard X-ray Imager and Soft Gamma-ray Detector onboard ASTRO-H demonstrate high sensitivity to hard X-ray (5-80 keV) and soft gamma-rays (60-600 keV), respectively. To reduce the background, both instruments are actively shielded by large, thick Bismuth Germanate scintillators. We have developed the signal processing system of the avalanche pho…
Special issue: The Vlasov equation, from space to laboratory plasmas
Califano, F.; Valentini, F.; Manfredi, G.
Spectral clustering for optical confirmation and redshift estimation of X-ray selected galaxy cluster candidates in the SDSS Stripe 82
Takey, A.; Mahmoud, E.; Shoukry, A.
We develop a galaxy cluster finding algorithm based on spectral clustering technique to identify optical counterparts and estimate optical redshifts for X-ray selected cluster candidates. As an application, we run our algorithm on a sample of X-ray cluster candidates selected from the third XMM-Newton serendipitous source catalog (3XMM-DR5) that a…
O+ and H+ above the polar cap: Observations and semikinetic simulations
Nilsson, H.; Slapak, R.; Barghouthi, I. A. +1 more
A one-dimensional direct simulation Monte Carlo model is used to study the outflow of O+ and H+ ions from 1.2 RE to 15.2 RE along two flight trajectories originating from the polar cap, namely, the central polar cap (CPC) and the cusp. To study the effect of varying geophysical conditions and to deduce t…
Searching for supergiant fast X-ray transients with Swift
D'Avanzo, P.; Campana, S.; Sbarufatti, B. +11 more
Supergiant fast X-ray transients (SFXTs) are high mass X-ray binaries (HMXBs) hosting a neutron star and an OB supergiant companion. We examine the available Swift data, as well as other new or archival/serendipitous data, on three sources: IGR J17407-2808, 2XMM J185114.3-000004, and IGR J18175-2419, whose X-ray characteristics qualify them as can…
Detecting Planet Pairs in Mean Motion Resonances via the Astrometry Method
Zhang, Hui; Zhou, Ji-Lin; Liu, Hui-Gen +2 more
Gaia is leading us into a new era with a high astrometry precision of ∼10 µas. Under such precision, astrometry can play an important role in detecting and characterizing exoplanets. In particular, we can identify planet pairs in mean motion resonances (MMRs), which constrain the formation and evolution of planetary systems. In accordance wi…