Search Publications
Major episodes in the geologic history of western Promethei Terra, Mars
Neukum, G.; Ivanov, M. A.; Korteniemi, J. +3 more
Geologic evolution of the western portion of Promethei Terra (40-50°S, 90-105°E) consists of two major episodes. The first was the formation of a late Noachian-early Hesperian volcanic province. During this episode a kilometer-thick suite (≈0.3 × 106 km3) of lavas accumulated to the south of Reull and Harmakhis Valles within …
The Stellar Population and Metallicity Distribution of the Sombrero Galaxy
Spitler, Lee; Mould, Jeremy
Hubble Space Telescope studies of the resolved stellar population of elliptical galaxies have shown that the galaxies form by steady accretion of gas which is all the while forming stars and chemically evolving to a metallicity distribution that is as high as solar composition in the most massive objects that have been analyzed and much lower for …
Five New INTEGRAL Unidentified Hard X-ray Sources Uncovered by Chandra
Capitanio, F.; Bird, A. J.; Fiocchi, M. +4 more
The IBIS imager on board INTEGRAL, with a sensitivity better than a milliCrab in deep observations and a point-source location accuracy on the order of few arcminutes, has thus far localized 723 hard X-ray sources in the 17-100 keV energy band, of which about 1/3 are still unclassified. The aim of this paper is to provide subarcsecond localization…
Mixed Azimuthal Scales of Flux Transfer Events
Fazakerley, A. N.; Lucek, E. A.; Milan, S. E. +2 more
Previous observations have allowed the scale size of flux transfer events (FTEs) to be determined both normal to the magnetopause and in the direction of motion of the FTE, but a key difference between some different models of FTE structure is their azimuthal scale size. Previous ground-based observations of the ionospheric signatures of FTEs indi…
Shocks and a Giant Planet in the Disk Orbiting BP Piscium?
Melis, C.; Zuckerman, B.; Song, Inseok +3 more
Spitzer Infrared Spectrograph data support the interpretation that BP Piscium, a gas and dust enshrouded star residing at high Galactic latitude, is a first-ascent giant rather than a classical T Tauri star. Our analysis suggests that BP Piscium's spectral energy distribution can be modeled as a disk with a gap that is opened by a giant planet. Mo…
Dust Abundance and Properties in the Nearby Dwarf Galaxies NGC 147 and NGC 185
Noriega-Crespo, Alberto; Marleau, Francine R.; Misselt, Karl A.
We present new mid- to far-infrared images of the two dwarf compact elliptical galaxies that are satellites of M31, NGC 185, and NGC 147, obtained with the Spitzer Space Telescope. Spitzer's high sensitivity and spatial resolution enable us for the first time to look directly into the detailed spatial structure and properties of the dust in these …
Hall magnetohydrodynamic effects for current sheet flapping oscillations related to the magnetic double gradient mechanism
Semenov, V. S.; Erkaev, N. V.; Biernat, H. K.
Hall magnetohydrodynamic model is investigated for current sheet flapping oscillations, which implies a gradient of the normal magnetic field component. For the initial undisturbed current sheet structure, the normal magnetic field component is assumed to have a weak linear variation. The profile of the electric current velocity is described by hy…
Orbital motion of the young brown dwarf companion TWA 5 B
Neuhäuser, R.; Schmidt, T. O. B.; Vogt, N. +1 more
Context. It is difficult to determine masses and test formation models for brown dwarfs, because they are always above the main sequence, so that there is a degeneracy between mass and age. However, for brown dwarf companions to normal stars, such determinations may be possible, because one can know the distance and age of the primary star. As a r…
Grey Milky Way extinction from SDSS stellar photometry
Brosch, Noah; Gorbikov, Evgeny
We report results concerning the distribution and properties of galactic extinction at high galactic latitudes derived from stellar statistics using the Sloan Digital Sky Survey (SDSS). We use the classical Wolf diagram method to identify regions with extinction, and derive the extinction and the extinction law of the dust using all five SDSS spec…
3D spectroscopy of merger Seyfert galaxy Mrk 334: nuclear starburst, superwind and the circumnuclear cavern
Moiseev, Alexei; Smirnova, Aleksandrina
We are presenting new results on kinematics and structure of the Mrk 334 Seyfert galaxy. Panoramic (3D) spectroscopy is performed at the 6-m telescope of the Special Astrophysical Observatory of the Russian Academy of Sciences using the integral-field Multi-Pupil Fiber Spectrograph (MPFS) and scanning Fabry-Pérot interferometer. The deep images ha…