Search Publications
Orbital Parameters and Chemical Composition of Four White Dwarfs in Post-Common-Envelope Binaries
Vennes, Stéphane; Lanz, Thierry; Chayer, Pierre +2 more
We present FUSE observations of the hot white dwarfs in the post-common-envelope binaries Feige 24, EUVE J0720-317, BPM 6502, and EUVE J2013+400. The spectra show numerous photospheric absorption lines, which trace the white dwarf orbital motion. We report the detection of C III, O VI, P V, and Si IV in the spectra of Feige 24, EUVE J0720-317, and…
Star cluster versus field star formation in the nucleus of the prototype starburst galaxy M 82
de Grijs, R.; Cerviño, M.; Barker, S.
We analyse high-resolution Hubble Space Telescope/Advanced Camera for Surveys imaging of the nuclear starburst region of M 82, obtained as part of the Hubble Heritage mosaic made of this galaxy, in four filters (Johnson-Cousins equivalent B, V, and I broad bands, and an Hα narrow-band filter), as well as subsequently acquired U-band images. We fin…
Time variability of X-ray sources in the M 31 centre field
Stiele, H.; Pietsch, W.; Haberl, F. +1 more
Aims:We present an extension to our XMM-Newton X-ray source catalogue of
Methods: As a source list we used our extended ca…
Inferring Photospheric Velocity Fields Using a Combination of Minimum Energy Fit, Local Correlation Tracking, and Doppler Velocity
Longcope, D. W.; Ravindra, B.; Abbett, W. P.
The minimum energy fit (MEF), a velocity inversion technique, infers all components of the photospheric velocity that are consistent with the induction equation. From the set of consistent velocity fields, it selects the smallest overall flow speed by minimizing a kinetic energy functional. If partial velocity information is available from other m…
Frequencies of wave packets of whistler-mode chorus inside its source region: a case study
Gurnett, D. A.; Pickett, J. S.; Trakhtengerts, V. Y. +5 more
Whistler-mode chorus is a structured wave emission observed in the Earth's magnetosphere in a frequency range from a few hundreds of Hz to several kHz. We investigate wave packets of chorus using high-resolution measurements recorded by the WBD instrument on board the four Cluster spacecraft. A night-side chorus event observed during geomagnetical…
Asteroid 2867 Steins. III. Spitzer Space Telescope observations, size determination, and thermal properties
Jorda, L.; Lamy, P. L.; Barucci, M. A. +6 more
Context: Asteroid 2867 Steins is the first target of the Rosetta space mission with a flyby scheduled in September 2008.
Aims: An early characterization is needed to optimize the flyby parameters and the science operations, and to maximize the scientific return.
Methods: We used the infrared spectrograph (IRS) of the Spitzer Space Telescop…
Spectroscopy and multiband photometry of the afterglow of intermediate duration γ-ray burst GRB 040924 and its host galaxy
Hornstrup, A.; Vreeswijk, P. M.; Wijers, R. A. M. J. +19 more
Aims: We present optical photometry and spectroscopy of the afterglow and host galaxy of gamma-ray burst GRB 040924. This GRB had a rather short duration of T90 ~2.4 s, and a well sampled optical afterglow light curve. We aim to use this dataset to find further evidence that this burst is consistent with a massive star core-collapse pro…
A Study of the ρ Ophiuchi Cloud: Mapping the Distribution and the Motions of Interstellar Gas
Welty, Daniel E.; Snow, Theodore P.; Destree, Joshua D.
Guest Investigator results from Hipparcos, combined with high-resolution optical spectra obtained with the Anglo-Australian Observatory, Kitt Peak National Observatory, and McDonald Observatory, are used to create a three-dimensional map of the stars and several interstellar gas components in the ρ Oph cloud complex. Many principal gas components …
A Comparison among Solar Diameter Measurements Carried Out from the Ground and outside Earth's Atmosphere
Thuillier, G.; Djafer, D.; Sofia, S.
The solar diameter has been measured since the 17th century, using different methods and instruments, and without a clear strategy of measurement, which could explain the lack of coherence between the results obtained. The present study confirms that the discrepancies between solar diameter measurements are mostly due to differences in instrumenta…
UV and Radio Observations of the Coronal Shock Associated with the 2002 July 23 Coronal Mass Ejection Event
Mancuso, S.; Avetta, D.
We report on the analysis of a fast coronal mass ejection (CME)-driven shock observed on 2002 July 23 with the Ultraviolet Coronagraph Spectrometer (UVCS) on board the Solar and Heliospheric Observatory (SOHO). The CME was first detected in white light by the Large Angle and Spectrometric Coronagraph Experiment (LASCO), and shock-associated type I…