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The Complex Structure of the Mg II λλ 2795.523, 2802.698 Å Regions of 64 Be Stars
Lyratzi, Evaggelia; Danezis, Emmanouel; Popovic, Luka C. +3 more
Here we consider the presence of absorption components shifted to the violet or red side of the main spectral line (satellite or discrete absorption components, i.e., SACs or DACs) in the regions of the Mg II resonance lines in Be stars as well as their kinematical characteristics. Namely, our objective is to check whether there exists a common ph…
Spatial structure of plasma flow associated turbulence in the Earth's plasma sheet
Nakamura, R.; Lucek, E. A.; Takada, T. +5 more
Using Cluster multipoint magnetic and plasma measurements we analyze the spatial structure of plasma flow-associated turbulence on 26 September 2005. The fortunate relative configuration of the spacecraft and the plasma flow allowed for the first time to compare the scale evolution of statistical moments both at the boundary and in the central par…
Photometric observations of Rosetta target asteroid 2867 Steins
Lowry, S. C.; Weissman, P. R.; Choi, Y. -J.
Asteroid 2867 Steins is one of two flyby targets of ESA's International Rosetta Mission, launched in March, 2004. We obtained CCD observations of Steins on April 14-16, 2004 at Table Mountain Observatory, California, in order to characterize the asteroid physically, information that is crucial for planning the Steins flyby. This study includes the…
X-Ray Constraints on Galaxy-Gas-Jet Interactions in the Dumbbell Galaxies NGC 4782 and NGC 4783 in the LGG 316 Galaxy Group
Hardcastle, M. J.; Forman, W. R.; Jones, C. +2 more
We present results from a 49.3 ks Chandra X-ray observation of the strongly interacting dumbbell galaxies NGC 4782 (3C 278) and NGC 4783 that constrain the kinematics of the interaction and models for bending the radio jets associated with NGC 4782. The galaxies are embedded in an approximately spherical distribution of group gas, centered on NGC …
Cool-Plasma Jets that Escape into the Outer Corona
Moore, Ronald L.; Sterling, Alphonse C.; Poletto, Giannina +2 more
We report on observations acquired in 2003 May during a SOHO-Ulysses quadrature campaign. The UVCS slit was set normal to the radial of the Sun along the direction to Ulysses at 1.7 Rsolar, at a northern latitude of 14.5°. From May 25 to May 28, UVCS acquired spectra of several short-lived ejections that represent the extension at highe…
Turbulent propagation of high-energy electrons in a solar coronal loop
Melnikov, V. F.; Stepanov, A. V.; Shibasaki, K. +1 more
Aims:We study the solar flare on 28 August 1999 observed by the Nobeyama Radioheliograph at 17 and 34 GHz and analyze the unusual behavior of microwave source (a coronal loop) after injections of high-energy electrons. The observations reveal a propagation velocity of the emission front along the loop of about 104 km s-1, whi…
The magnetic structure of an earthward-moving flux rope observed by Cluster in the near-tail
Lucek, E.; Dunlop, M.; Liu, Z. X. +6 more
We investigate the magnetic structure of a small earthward-moving flux rope observed by Cluster in the near-Earth plasma sheet through application of the Grad-Shafranov (GS) technique to reconstruct the transverse magnetic field distribution perpendicular to the flux rope axis at X=-14.75 RE. We find that the principal axis of the flux …
Young nuclei in dwarf elliptical galaxies
Prugniel, Ph.; Afanasiev, V. L.; Chilingarian, I. V. +1 more
We report the discovery of young embedded structures in three diffuse elliptical galaxies (dE) in the Virgo cluster: IC 783, IC 3468, and IC 3509. We performed 3D spectroscopic observations of these galaxies with the MPFS spectrograph at the 6-m Special Astrophysical Observatory telescope and obtained spatially resolved distributions of kinematic …
Possible Precession Motion in the Bipolar Proto-Planetary Nebula IRAS 17441-2411
Volk, Kevin; Kwok, Sun; Hrivnak, Bruce J.
Mid-infrared imaging of two bipolar proto-planetary nebulae, IRAS 17150-3224 and IRAS 17441-2411, was obtained with the Gemini telescope. Dust emissions are detected in both the bipolar lobes and in the equatorial region of IRAS 17441-2411. In particular, the orientation of the axis of the infrared torus is found to be offset by 23° from the bipol…
A precessing accretion disc in the intermediate polar XY Arietis?
Mukai, K.; Norton, A. J.
Context: XY Ari is the only intermediate polar to show deep X-ray eclipses of its white dwarf. Previously published observations with Ginga and Chandra have also revealed a broad X-ray orbital modulation, roughly antiphased with the eclipse, and presumed to be due to absorption in an extended structure near the edge of an accretion disc. The X-ray…