Search Publications
Hydrographs of a Martian flood from the breach of Galilaei Crater
Coleman, Neil M.
Spectacular floods were spawned on Mars when large craters filled to overtopping and catastrophically breached. The wealth of data now available permits quantitative analysis of these ancient floods. Galilaei Crater is examined here, along with the likely sources of its water and the processes that formed Tana Vallis, its 1-km-deep outflow channel…
Cusp dynamics under northward IMF using three-dimensional global particle-in-cell simulations
Lembège, B.; Cai, D.; Esmaeili, A. +1 more
The interaction of the solar wind with the terrestrial magnetosphere is analyzed with the help of three-dimensional (3-D) global, full-electromagnetic particle-in-cell (PIC) simulations, in the configuration where the interplanetary magnetic field (IMF) is steadily northward. The present study is mainly focused on the cusp region and associated pa…
Topside of the martian ionosphere near the terminator: Variations with season and solar zenith angle and implications for the origin of the transient layers
Huang, Qian; Zhang, Jie; Orosei, Roberto +1 more
In this paper, the morphological variations of the M2 layer of the martian ionosphere with the martian seasons and solar zenith angle (SZA) at the terminator are investigated. The data used are the MARSIS (Mars Advanced Radar for Subsurface and Ionosphere Sounding) measurements (approximately 5000 ionograms) that were acquired from 2005 to 2012, w…
From radio to TeV: the surprising spectral energy distribution of AP Librae
Fortin, P.; Horan, D.; Giebels, B. +10 more
Following the discovery of high-energy (HE; E > 10 MeV) and very-high-energy (VHE; E > 100 GeV) γ-ray emission from the low-frequency-peaked BL Lac (LBL) object AP Librae, its electromagnetic spectrum is studied over 60 octaves in energy. Contemporaneous data in radio, optical and UV together with the (non-simultaneous) γ-ray data are used t…
Statistics of the Velocity Gradient Tensor in Space Plasma Turbulent Flows
Consolini, Giuseppe; Materassi, Massimo; Federica Marcucci, Maria +1 more
In the last decade, significant advances have been presented for the theoretical characterization and experimental techniques used to measure and model all of the components of the velocity gradient tensor in the framework of fluid turbulence. Here, we attempt the evaluation of the small-scale velocity gradient tensor for a case study of space pla…
A XMM-Newton observation of a sample of four close dwarf spheroidal galaxies
Testa, V.; Nucita, A. A.; De Paolis, F. +2 more
We present the results of the analysis of deep archival XMM-Newton observations towards the dwarf spheroidal galaxies Draco, Leo I, Ursa Major II (UMa II) and Ursa Minor (UMi) in the Milky Way neighbourhood. The X-ray source population is characterized and cross-correlated with available databases to infer their nature. We also investigate if inte…
Intersunspot Microwave Sources
Bakunina, I. A.; Melnikov, V. F.; Solov'ev, A. A. +1 more
We studied a number of solar active regions using two-dimensional spatially resolved microwave observations. Data from the Nobeyama Radioheliograph and the Siberian Solar Radio Telescope together with observations by the Michelson Doppler Imager (MDI) onboard the Solar and Heliospheric Observatory (SOHO) have allowed us to identify long-lived inte…
2D MHD and 1D HD Models of a Solar Flare—a Comprehensive Comparison of the Results
Srivastava, A. K.; Murawski, K.; Falewicz, R. +1 more
Without any doubt, solar flaring loops possess a multithread internal structure that is poorly resolved, and there are no means to observe heating episodes and thermodynamic evolution of the individual threads. These limitations cause fundamental problems in numerical modeling of flaring loops, such as selection of a structure and a number of thre…
Formation of a quasi-one-dimensional current sheet in the laboratory experiment and in the Earth's magnetotail
Petrukovich, A. A.; Artemyev, A. V.; Vasko, I. Y. +2 more
Two-dimensional current sheets (CSs) generated in the CS-3D laboratory device are considered. Results obtained in the laboratory experiment are compared with spacecraft observations of CSs in the Earth's magnetotail. The longitudinal and transverse CS structures, as well as CS evolution during the thinning process are studied. It is demonstrated t…
Variability of the soft X-ray excess in IRAS 13224-3809
Papadakis, I. E.; Kammoun, E. S.; Sabra, B. M.
We study the soft excess variability of the narrow line Seyfert 1 galaxy IRAS 13224-3809. We considered all five archival XMM-Newton observations, and we applied the flux-flux plot (FFP) method. We found that the FFPs were highly affected by the choice of the light curves' time bin size, most probably because of the fast and large amplitude variat…