Search Publications
Multi-component absorption lines in the HST spectra of α Scorpii B
Reimers, D.; Baade, R.
Context: Extended atmospheres of late-type supergiants are of special interest with regard to the mass-loss process, the circumstellar physico-chemistry, and the evolution of stars.
Aims: The circumstellar envelope of α Sco A (M1.5 Iab) has been subject of intensive studies. Nevertheless the mechanism that is responsible for the mass outflow i…
A Potential Galaxy Threshing System in the COSMOS Field
Aussel, H.; Sanders, D. B.; Murayama, T. +26 more
We report on the discovery of a new potential galaxy threshing system in the COSMOS 2 square degree field using the prime-focus camera, Suprime-Cam, on the 8.2 m Subaru Telescope. This system consists of a giant elliptical galaxy with MV~-21.6 and a tidally disrupted satellite galaxy with MV~-17.7 at a photometric redshift of…
Jet disc coupling in black hole binaries
Malzac, Julien
In the last decade multi-wavelength observations have demonstrated the importance of jets in the energy output of accreting black hole binaries. The observed correlations between the presence of a jet and the state of the accretion flow provide important information on the coupling between accretion and ejection processes. After a brief review of …
Estimating the Structure and Geometry of Winds from Luminous Blue Variables via Fitting the Continuum Energy Distributions
Li, Y.; Guo, J. H.
By combining the UV spectra from IUE with photometric data in the optical band, we present a quantitative study on the continuum energy distributions of LBVs to determine the structure and geometry of LBV winds. It is shown that the shape of continuum energy distributions around the Balmer jump is sensitive to the velocity law of LBV winds. A simp…
Polarization measurements of Saturn Electrostatic Discharges with Cassini/RPWS below a frequency of 2 MHz
Gurnett, D. A.; Kurth, W. S.; Fischer, G. +2 more
Early in 2006 the RPWS (Radio and Plasma Wave Science) instrument and the ISS (Imaging Science Subsystem) onboard the Cassini spacecraft detected a lightning storm on Saturn that lasted for about one month. The RPWS measured the so-called SEDs (Saturn Electrostatic Discharges), which are high frequency radio signals produced by lightning discharge…
Modeling quasi-specular scattering from the surface of Titan
Tyler, G. Leonard; Sultan-Salem, Ahmed K.
The Cassini spacecraft obtained several scattering observations of the surface of Titan. Four data sets, TA-Inbound, TA-Outbound, T3-Outbound, and T8-Inbound, include scatterometer data for small angles of incidence. Analysis of these data sets provides an example use of a new generalized fractal-based quasi-specular scattering law that gives the …
Orbit, Masses and Spectral Analysis of the Visual Binary A 2329
Andrade, M.
A revised orbit for the visual binary A 2329, calculated taking into account a set of interferometric measures distributed over one orbital revolution, is presented. On the basis of new orbital elements and the Hipparcos parallax, a dynamical mass of the system of 1.25+/-0.14 M_⊙ is obtained. By considering new spectral data, we confirm its MK spe…
UV and optical emission lines from the z ~ 2.6 radio galaxy 0828+193: spatially resolved measurements
Humphrey, A.; Iwamuro, F.; Villar-Martín, M. +3 more
We present an investigation into the spatial variation of the rest-frame ultraviolet (UV) and optical line and continuum emission along the radio axis of the z ~ 2.6 radio galaxy 0828+193, using long-slit spectra from the Keck II and Subaru telescopes. Line brightnesses, line ratios and electron temperatures are examined, and their relationship wi…
QED can explain the non-thermal emission from SGRs and AXPs: variability
Heyl, Jeremy S.
Owing to effects arising from quantum electrodynamics (QED), magnetohydrodynamical fast modes of sufficient strength will break down to form electron-positron pairs while traversing the magnetospheres of strongly magnetised neutron stars. The bulk of the energy of the fast mode fuels the development of an electron-positron fireball. However, a sma…
Magnetic Flux in the Solar Convective Envelope Inferred from Initial Observations of Sunspots
Hiremath, K. M.; Lovely, M. R.
Different life spans of sunspots suggest their origin at different depths, and by measuring magnetic fluxes from their first observation on the surface, one can estimate the strength of magnetic flux at different anchoring depths. From SOHO MDI magnetograms, we infer the strength of magnetic flux and rate of emergence of magnetic flux at different…