Search Publications
XMM-Newton monitoring observations of Mrk 3
Nandra, K.; Georgantopoulos, I.; Akylas, A.
We present monitoring analysis of 8 XMM-Newton observations of the Seyfert 2 galaxy Mrk 3, spanning a period of ∼19 months. The continuum flux in the 3-12 keV band remains constant during this observing period. The X-ray spectrum is well described, in agreement with previous works, by a highly absorbed (N_H>1024 cm-2) powe…
Search for the periodicity in brightness and radial velocity variations of the runaway star HD 218915
Barannikov, A. A.
An analysis of the variations in the brightness and radial velocity of the high-velocity (runaway) star HD 218915 based on the author's ground-based Crimean observations and from Hipparcos data is presented. The analysis leads to the conclusion that there is a periodic component in the brightness and radial velocity variations of HD 218915. The pe…
``The ESA XMM-Newton Science Operations Centre: Making Basic Space Science Available to the Whole Scientific World''
Metcalfe, Leo; Guainazzi, Matteo; Gabriel, Carlos
XMM-Newton is a major X-ray observatory of the European Space Agency (ESA). Its observing time is open to astronomers from the whole scientific community on a peer reviewed competitive basis. The Science Operations Centre, located at ESA's premises in Villafranca del Castillo, Spain, is responsible for the instrument operations, as well as for all…
Galileo Avionica's Technologies and Instruments for Planetary Exploration
Re, E.; Battistelli, E.; Falciani, P. +3 more
Several missions for planetary exploration, including comets and asteroids, are ongoing or planned by the European Space Agencies: Rosetta, Venus Express, Bepi Colombo, Dawn, Aurora and all Mars Programme (in its past and next missions) are good examples. The satisfaction of the scientific request for the mentioned programmes calls for the develop…
A search for two-component energetic proton events observed on board SOHO
Kocharov, Leon; Torsti, Jarmo; Al-Sawad, Amjad +1 more
We examined solar energetic particle (SEP) events from May 1996 through April 2000 that showed evidence for two peaks of intensity, separated by 3-24 hours, in the energy range ∼1-20 MeV, observed with the Energetic and Relativistic Nuclei and Electron instrument (ERNE) onboard Solar and Heliospheric Observatory (SOHO). Of 88 clear SEP events obse…
Empirical Modeling of TSI: A Critical View
de Toma, Giuliana; White, Oran R.
Solar empirical models based on regression of two variability indices for radiation from the photosphere and chromosphere fit total solar irradiance (TSI) observations with accuracy comparable to the precision reported for the observations themselves. However, the physical meaning of the fitting coefficients and their stability during different ph…
Two years of INTEGRAL observation of the BHC IGR J17464-3213
Capitanio, F.; Ubertini, P.; Bazzano, A. +4 more
On March 2003, IBIS, the γ-ray imager on board the INTEGRAL satellite, detected an outburst from a new source, IGR J17464-3213, that turned out to be an HEAO-1 transient, namely H1743-322. The spectral and temporal evolutions of the source were observed by INTEGRAL in different periods. Also RXTE observed the source for the first time on 2003 Marc…
Pulsating B Stars Discovered by HIPPARCOS
Eyer, L.; Aerts, C.; De Cat, P. +4 more
We present a classification of 267 new variable B-type stars discovered by Hipparcos, which results in, among others, a huge number of new Slowly Pulsating B stars and several supergiants with ? Cyg-type variations. Our results clearly point out the bias towards short-period variables of earlier, ground-based surveys of variable stars.
The po…Discovery of a cluster of galaxies behind the Milky Way: X-ray and optical observations
Motch, C.; Mendes de Oliveira, C.; Janot-Pacheco, E. +2 more
We report the discovery of
Analysis of chromospheric activity in late type stars from UV observations
Buccino, A. P.; Mauas, P. J. D.
The purpose of this work is to study the chromospheric activity of the latest main sequence stars, which are generally observed in low dispersion. In this work, we present a calibration between Mount Wilson index and the Mg II line-core flux, measured on simultaneous low resolution IUE spectra. FULL TEXT IN SPANISH