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Electric Fields and Plasma Processes in the Auroral Downward Current Region, Below, Within, and Above the Acceleration Region
Marklund, G. T.
The downward field-aligned current region plays an active role in magnetosphere-ionosphere coupling processes associated with aurora. A quasi-static electric field structure with a downward parallel electric field forms at altitudes between 800 km and 5000 km, accelerating ionospheric electrons upward, away from the auroral ionosphere. A wealth of…
Discovery of slow X-ray pulsations in the high-mass X-ray binary 4U 2206+54
Wilms, J.; Reig, P.; Torrejón, J. M. +3 more
Context: The source 4U 2206+54 is one of the most enigmatic high-mass X-ray binaries. In spite of intensive searches, X-ray pulsations have not been detected in the time range 10-3-103 s. A cyclotron line at ~30 keV has been suggested by various authors but never detected with significance. The stellar wind of the optical com…
Hot Plasma in Nonflaring Active Regions Observed by the Extreme-Ultraviolet Imaging Spectrometer on Hinode
Warren, Harry P.; Doschek, George A.; Young, Peter R. +1 more
The Extreme-Ultraviolet Imaging Spectrometer (EIS) on the Hinode spacecraft obtains high-resolution spectra of the solar atmosphere in two wavelength ranges: 170-210 and 250-290 Å. These wavelength regions contain a wealth of emission lines covering temperature regions from the chromosphere/transition region (e.g., He II, Si VII) up to flare tempe…
Venus cloud top winds from tracking UV features in Venus Monitoring Camera images
Jaumann, R.; Hviid, S. F.; Matz, K. -D. +10 more
To date dynamical observations of the Venus clouds have delivered mainly either only short-term or long-term averaged results. With the Venus Monitoring Camera (VMC) it finally became possible to investigate the global dynamics with a relatively high resolution in space and time on a long-term basis. Our findings from manual cloud feature wind tra…
Comprehensive Observations of a Solar Minimum Coronal Mass Ejection with the Solar Terrestrial Relations Observatory
Plunkett, S. P.; Howard, R. A.; Wood, B. E. +1 more
We perform the first kinematic analysis of a coronal mass ejection (CME) observed by both imaging and in situ instruments on board the Solar Terrestrial Relations Observatory (STEREO). Launched on 2008 February 4, the CME is tracked continuously from initiation to 1 AU using the imagers on both STEREO spacecraft, and is then detected by the partic…
Probing Star Formation at Low Metallicity: The Radio Emission of Super Star Clusters in SBS 0335-052
Hunt, Leslie K.; Johnson, Kelsey E.; Reines, Amy E.
We present high-resolution radio-continuum observations of the nascent starburst in the metal-poor galaxy SBS 0335-052. These radio data were taken with the Very Large Array and include observations at 0.7 cm, 1.3 cm, 2 cm, 3.6 cm, and 6 cm. These observations enable us to probe the thermal radio nebulae associated with the extremely young star-fo…
Magnetic island formation between large-scale flow vortices at an undulating postnoon magnetopause for northward interplanetary magnetic field
Glassmeier, K. -H.; Le Contel, O.; Hasegawa, H. +10 more
Time History of Events and Macroscale Interactions during Substorms multispacecraft observations are presented for a ~2-h-long postnoon magnetopause event on 8 June 2007 that for the first time indicate that the trailing (sunward) edges of Kelvin-Helmholtz (KH) waves are commonly related to small-scale <0.56 R E magnetic islands or…
Three-dimensional Radiative Transfer Modeling of the Polarization of the Sun's Continuous Spectrum
Shchukina, Nataliya; Trujillo Bueno, Javier
Polarized light provides the most reliable source of information at our disposal for diagnosing the physical properties of astrophysical plasmas, including the three-dimensional (3D) structure of the solar atmosphere. Here we formulate and solve the 3D radiative transfer problem of the linear polarization of the solar continuous radiation, which i…
Spatial Distribution of the Galactic Center Diffuse X-Rays and the Spectra of the Brightest 6.4keV Clumps
Koyama, Katsuji; Matsumoto, Hironori; Nobukawa, Masayoshi +4 more
The high energy resolution and low background, particularly in the hard X-ray band, of the X-ray Imaging Spectrometer onboard Suzaku provide excellent spectra of the Galactic center diffuse X-rays (GCDX). This paper reports on the results of spatially resolved spectroscopy of the GCDX. The most pronounced features of the GCDX are the K-shell trans…
Spectroscopic Observations of Hot Lines Constraining Coronal Heating in Solar Active Regions
Klimchuk, J. A.; Patsourakos, S.
Extreme-ultraviolet observations of warm coronal loops suggest that they are bundles of unresolved strands that are heated impulsively to high temperatures by nanoflares. The plasma would then have the observed properties (e.g., excess density compared with static equilibrium) when it cools into the 1-2MK range. If this interpretation is correct, …