Search Publications
CCD astrometry and components instrumental magnitude difference of 432 Hipparcos wide visual double stars
Gavras, P.; Sinachopoulos, D.; Dionatos, O. +2 more
Context: We measured the angular separations, position angles, Δ V, Δ y and Δ I of wide visual double stars during the period 2003-2005. At least one component of the double stars in our sample has an entry in the Hipparcos catalogue.
Aims: Our measurements are a contribution to the study of the nature of these double stars.
Methods: The n…
INTEGRAL high energy detection of the transient IGR J11321-5311
Hill, A. B.; Bird, A. J.; Ubertini, P. +5 more
Context: The transient hard X-ray source IGR J11321-5311 was discovered by INTEGRAL on June 2005, during observations of the Crux spiral arm. To date, this is the only detection of the source to be reported by any X/γ-ray mission.
Aims: To characterize the behaviour and hence the nature of the source through temporal and spectral IBIS analysis…
Coronal mass ejections and the associated activities on the solar disk observed on October 26, 2003
Zhang, H.; Lin, J.; Stenborg, G. A. +1 more
Aims:Coronal mass ejections (CMEs) are usually considered fast (slow) if their velocities are greater (less) than 500 km s-1. It is generally believed that fast CMEs are well associated with activity manifested on the solar disk, such as solar flares, and that slow CMEs are often associated with filament eruptions out of active regions …
The nearby QSO host I Zw 1 : the stellar disk and adjacent objects
Saviane, I.; Scharwächter, J.; Eckart, A. +2 more
Context: The relation between tidal interactions, starbursts, and the onset and/or fueling of active galactic nuclei (AGN) is a matter of debate.
The in-flight monitoring and validation of the SOHO CDS Normal Incidence Spectrometer radiometric calibration
Lanzafame, A. C.; Brooks, D. H.; Thompson, W. T. +3 more
The scientific return from an extreme-ultraviolet spectrometer depends on the accuracy and precision of its radiometric calibration. For the Coronal Diagnostic Spectrometer on SOHO, radiometric calibration started pre-launch in the laboratory and continued after launch by making comparison measurements of the same area of the Sun with calibrated s…
ISOCAM mid-infrared spectroscopy and NIR photometry of the HII complex N4 in the Large Magellanic Cloud
Boulanger, F.; Sauvage, M.; Contursi, A. +3 more
Context: We present the analysis of ISOCAM-CVF and the J, H, and Ks photometry data for the HII region complex N4 in the Large Magellanic Cloud (LMC).
Aims: The aim is twofold: 1) to study the connection between the interstellar medium and the star content of this region; 2) to investigate the effects of the lower-than-Galactic meta…
An XMM-Newton view of the X-ray flat radio-quiet quasar PG 1416-129
Nandra, K.; Turner, T. J.; Porquet, D. +3 more
Aims:The radio-quiet quasar PG 1416-129 (z=0.129) exhibits atypical optical and X-ray properties. Between 1990 and 2000, in response to its optical continuum decrease, the “classical” broad component of Hβ almost completely disappeared, with a factor of 10 decrease in the line flux. In addition, the width of the broad component of the Hβ line decr…
X-ray detection of the substellar twin 2MASS J11011926-7732383 AB
Micela, G.; Stelzer, B.
Context: 2MASS J11011926-7732383 AB (hereafter 2M 1101 AB), located in the Cha I star forming region, is a rare wide-separation brown dwarf binary. Being spatially resolvable in many wavebands, it is a unique target for studying the properties of substellar twins.
Aims: Here, we exploit the coeval pair 2M 1101 AB to examine the influence of ph…
Modeling time delays in the X-ray spectrum of the Seyfert galaxy MCG-6-30-15
Ponti, G.; Karas, V.; Czerny, B. +1 more
Aims:We propose a reflection model of the time delays detected during an exceptionally bright, single flare in MCG-6-30-15. We consider a scenario in which the delays of the hard X-rays with respect to the soft X-rays are caused by the presence of the delayed reflection component.
Methods: We employ a model of the flare, which is accompanied b…
Electron density and carriers of the diffuse interstellar bands
Galazutdinov, G. A.; Gnaciński, P.; Sikorski, J. K.
We have used the ionisation equilibrium equation to derive the electron density in interstellar clouds in the direction of 13 stars. A linear relation was found that allows determination of the electron density from the Mg I and Mg II column densities in diffuse clouds. The comparison of a normalised equivalent width of 12 DIBs with the electron d…