Search Publications
Optimized data masks for focussed solar tomography: background and artificial diagnostic experiments
Thompson, M. J.; Hughes, S. J.; Pijpers, F. P.
Context: The use of solar tomography for detecting subsurface features in the Sun is now well established. It customarily proceeds from an analysis of data on the solar surface given weightings in a predetermined geometric (e.g. centre-annulus) configuration.
Aims: We seek to improve these weightings by developing a scheme for choosing optimal…
Discovery of a New X-Ray Transient Source in the Scutum Region with Suzaku
Ishida, Manabu; Kokubun, Motohide; Koyama, Katsuji +7 more
During an observation of the Galactic plane in the Scutum region with the Suzaku satellite, we discovered a new X-ray transient source, designated Suzaku J1844-0404. Compared with previous Chandra observations of the same field, four Chandra X-ray sources exist within the current positional uncertainty of Suzaku J1844-0404. A firm identification i…
Variability and evolution in various classes of post-AGB stars
Jeffery, C. S.; Şahin, T.
We aim to compare properties of early-type post-asymptotic giant-branch (post-AGB) stars, including normal first-time B-type post-AGB stars, and extreme helium stars (EHes). Hipparcos photometry for 12 post-AGB stars and 7 EHe stars has been analyzed; 5 post-AGB stars are clearly variable. The Hipparcos data are not sufficiently sensitive to detec…
MIMS—A relational database of imagery on Mars
Vaz, D.; Alves, E. Ivo
Mars Image Mining System (MIMS) is a relational database of internet links to most of the images which were acquired by missions Mariner 9, Viking 1 and 2, Mars Global Surveyor, Mars Odyssey and Mars Express (a total of 329,240 images on December 15, 2005). Unlike existing online databases, it allows to search for images of several missions simult…
INTEGRAL observations of the gamma-ray burst on March 11, 2007
Sunyaev, R. A.; Sazonov, S. Yu.; Molkov, S. V.
On March 11, 2007, the INTEGRAL observation discovered and localized a gamma-ray burst in the sky from which an early infrared afterglow was then detected. We present our timing and spectral analyses of the data from the ISGRI detector of the IBIS telescope. The burst consists of one ∼40-s-long peak during which a fluence of ∼3 × 10-6 e…
Filamentary structures in planetary nebulae
Gahm, Gösta F.; Carlqvist, Per; Dahlgren, Hanna
We have studied small-scale, filamentary features in 14 planetary nebulae and found that some structures are recurrent and shaped like the letters V and Y, with the apex or stem pointing toward the central parts of the nebula. Two such filaments containing dust, one in NGC 3132 and one in NGC 7293, were investigated in more detail. The mass and de…
Low-frequency waves upstream and downstream of the terrestrial bow shock
Narita, Yasuhito
This is a Ph.D. thesis abstract.
Hubble Space Telescope Far-Ultraviolet Spectroscopy of the Dwarf Nova VW Hydri in Superoutburst
Sion, Edward M.; Merritt, Jason; Night, Christopher
We obtained three consecutive Hubble Space Telescope spectroscopic observations of a single superoutburst of the dwarf nova VW Hydri. The spectra cover the beginning, middle, and end of the superoutburst. All of the spectra are dominated by strong absorption lines due to C III (1175 Å), Lyα (1216 Å), N IV (1238 and 1242 Å), S II (1260-1565 Å), S I…
Plasma sheet fine structure at high latitude
Rème, H.; Kistler, L.; Lennartsson, O. W.
High-resolution ion observations made in recent years, by the TIMAS instrument on the Polar satellite and other instruments, reveal a dynamic and finely structured plasma sheet, at least at high latitude. This study invokes multipoint Cluster observations with the CIS CODIF instruments (ion composition and distribution function) to determine wheth…
Experiencing Venus: Clues to the origin, evolution, and chemistry of terrestrial planets via in-situ exploration of our sister world
Baines, Kevin H.; Crisp, David; Russell, Christopher T. +5 more
We review the current state of knowledge of (1) the origin and evolution of Venus and (2) the photochemical and thermochemical processes occurring in the middle and lower atmosphere there. For each, we review the promise of on-going and planned orbital observations by ESA's Venus Express and Japan's Venus Climate Orbiter missions. We review the ne…