Search Publications
Fast transport of resonant electrons in phase space due to nonlinear trapping by whistler waves
Krasnoselskikh, V.; Artemyev, A. V.; Agapitov, O. V. +4 more
We present an analytical, simplified formulation accounting for the fast transport of relativistic electrons in phase space due to wave-particle resonant interactions in the inhomogeneous magnetic field of Earth's radiation belts. We show that the usual description of the evolution of the particle velocity distribution based on the Fokker-Planck e…
Probing spatial homogeneity with LTB models: a detailed discussion
Bartelmann, M.; Lewis, G. F.; Meyer, S. +2 more
Do current observational data confirm the assumptions of the cosmological principle, or is there statistical evidence for deviations from spatial homogeneity on large scales? To address these questions, we developed a flexible framework based on spherically symmetric, but radially inhomogeneous Lemaître-Tolman-Bondi (LTB) models with synchronous B…
Electromagnetic ion cyclotron rising tone emissions observed by THEMIS probes outside the plasmapause
Omura, Yoshiharu; Angelopoulos, Vassilis; Shoji, Masafumi +3 more
We report observations of electromagnetic ion cyclotron (EMIC) triggered emissions observed by the Time History of Events and Macroscale Interactions during Substorms (THEMIS) probes outside the plasmasphere. Although these phenomena have recently received much attention because of the possibility of strong interaction with particles, only a few e…
Composition of Surface Materials on the Moons of Mars
Thomas, Nicolas; Pieters, Carle M.; Murchie, Scott +1 more
The two small asteroid-like bodies orbiting Mars, Phobos and Deimos, are low albedo and exhibit similar visible to near-infrared spectra. Determining the origin of these moons is closely tied to determining their composition. From available spectroscopic data Phobos exhibits two distinct types of materials across its surface, and data from both Ma…
AKARI IRC 2.5-5 µm Spectroscopy of Infrared Galaxies over a Wide Luminosity Range
Nakagawa, Takao; Shirahata, Mai; Oyabu, Shinki +4 more
We present the result of a systematic infrared 2.5-5 µm spectroscopic study of 22 nearby infrared galaxies over a wide infrared luminosity range (1010 L ⊙ < L IR < 1013 L ⊙) obtained from the AKARI Infrared Camera (IRC). The unique band of the AKARI IRC spectroscopy enables us to a…
Extended Structure and Fate of the Nucleus in Henize 2-10
Seth, Anil C.; Nguyen, Dieu D.; den Brok, Mark +3 more
We investigate the structure and nuclear region of the black hole (BH) hosting galaxy Henize 2-10. Surface brightness profiles are analyzed using Magellan/Megacam g- and r-band images. Excluding the central starburst, we find a best-fit two-component Sérsic profile with n in ~ 0.6, r eff, in ~ 260 pc and n out ~ 1.…
Plasma Dynamics Above Solar Flare Soft X-Ray Loop Tops
Doschek, G. A.; Warren, H. P.; McKenzie, D. E.
We measure non-thermal motions in flare loop tops and above the loop tops using profiles of highly ionized spectral lines of Fe XXIV and Fe XXIII formed at multimillion-degree temperatures. Non-thermal motions that may be due to turbulence or multiple flow regions along the line of sight are extracted from the line profiles. The non-thermal motion…
The quiescent X-ray spectrum of accreting black holes
Reis, Rubens C.; Miller, Jon M.; Cackett, Edward M. +2 more
The quiescent state is the dominant accretion mode for black holes on all mass scales. Our knowledge of the X-ray spectrum is limited due to the characteristic low luminosity in this state. Herein, we present an analysis of the sample of dynamically confirmed stellar-mass black holes observed in quiescence in the Chandra/XMM-Newton/Suzaku era resu…
Formation history of polycyclic aromatic hydrocarbons in galaxies
Seok, Ji Yeon; Hirashita, Hiroyuki; Asano, Ryosuke S.
Polycyclic aromatic hydrocarbons (PAHs) are some of the major dust components in the interstellar medium (ISM). We present our evolution models for the abundance of PAHs in the ISM on a galaxy-evolution time-scale. We consider shattering of carbonaceous dust grains in interstellar turbulence as the formation mechanism of PAHs while the PAH abundan…
Direct observation of closed magnetic flux trapped in the high-latitude magnetosphere
Dandouras, I.; Fazakerley, A. N.; Milan, S. E. +3 more
The structure of Earth’s magnetosphere is poorly understood when the interplanetary magnetic field is northward. Under this condition, uncharacteristically energetic plasma is observed in the magnetotail lobes, which is not expected in the textbook model of the magnetosphere. Using satellite observations, we show that these lobe plasma signatures …