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Chemical abundances in AGN : X-ray/UV campaign on Mrk 279 .
Arav, Nahum
We present the first reliable chemical abundances determination in an AGN outflow. The abundances are extracted from the deep and simultaneous FUSE and HST/STIS observations of Mrk 279. This data-set is exceptional for it's high signal-to-noise, unblended doublet troughs and little galactic absorption contamination. These attributes allow us to so…
The HIPPARCOS Mission: a New Era for Variable Star Astronomy
Eyer, L.; Grenon, M.
Initially planned as a pure astrometric mission, Hipparcos was optimized to produce the highest achievable photometric accuracy in the Hp broad-band and in the Tycho BT and VT bands. A complex calibration process allowed to cope with the rapid change of the optics and to fix the magnitude scale to better than 0.001 magnitude throughout the mission…
Space Physics: Breaking through the lines
Paschmann, Götz
Magnetic field lines are known to reorganize themselves in plasmas, converting magnetic to particle energy. Evidence harvested from the solar wind implies that the scale of the effect is larger than was thought.
Dust scattering X-ray expanding rings around gamma-ray bursts
Tiengo, A.; Mereghetti, S.; Vianello, G.
Scattering by dust grains in our Galaxy can produce X-ray halos, visible as expanding rings, around GRBs. This has been observed in three GRBs to date, allowing to derive accurate distances for the dust clouds as well as some constraints on the prompt GRB X-ray emission that was not directly observed. We developed a new analysis method to study du…
Energetic electron signatures in an active magnetotail plasma sheet
Grande, M.; Davies, J. A.; Fazakerley, A. N. +10 more
Particles with energies of tens to hundreds of keV provide a powerful diagnostic of the acceleration processes that characterise the Earth's magnetosphere, in particular the highly dynamic nightside plasma sheet. Such energetic particles can be detected by the RAPID experiment, onboard the quartet of Cluster spacecraft. We present results from the…
Ultraviolet Studies Of Interacting Binaries
Shore, Steven N.; Long, Knox S.; Marsh, Thomas R. +4 more
Interacting Binaries consist of a variety of stellar objects in different stages of evolution and those containing accreting compact objects still represent a major challenge to our understanding of not only close binary evolution but also of the chemical evolution of the Galaxy. These end-points of binary star evolution are ideal laboratories for…
Cataclysmic Variables Observed with INTEGRAL
Simon, Vojtech; Hudec, René; Munz, Filip +1 more
We discuss selected results of observations of cataclysmic variables (CVs) and related objects by the instruments IBIS (far X-ray and gamma-ray imager) and OMC (Optical Monitoring Camera) onboard INTEGRAL. We concentrate on the analysis of the time behaviour of the intermediate polar (IP) V1223 Sgr, seen simultaneously by IBIS and OMC in a state w…
Programs for laser-AO assisted integral-field spectrometers on ionized flows
Cecil, Gerald
An AO-assisted integral-field spectrograph is becoming the most efficient tool with which to explore ionized gas outflows. It maps faint spectral lines that diagnose cloud dust content, gas pressure, excitation mechanism, and chemical abundances. Coupled with recent improvements in photoionization models, the total mass hence flow energetics can b…
Establishing Observational Baselines for Two δ Scuti Variables: V966 Herculis and V1438 Aquilae
Hintz, Eric G.; Rose, Michael B.; Bush, Tabitha C. +1 more
We have examined the previously understudied δ Scuti stars V966 Herculis and V1438 Aquilae. We find that V966 Her is a stable pulsator with a refined period of 0.1330302 days with a full V amplitude of 0.096 mag. We also find that V966 Her has an average radial velocity of +7.8 km s-1, a full radial velocity amplitude of 7.6 km s-1…
On the variability of Saturn's equatorial jet at cloud top level
Hueso, R.; Sánchez-Lavega, A.; Pérez-Hoyos, S.
Saturn's Equatorial jet is apparently highly variable in wind speed at the upper cloud level with changes, between 1980-81 and 1994-2004, amounting up to a 40% in its peak value. However, there is some controversy if this is a real change in the winds or an effect due to clouds placed at different altitude levels where a vertical wind shear is pre…