Search Publications
INTEGRAL observations of the blazar 3C 454.3 in outburst
Maraschi, L.; Tagliaferri, G.; Ghisellini, G. +22 more
In Spring 2005, the blazar 3C 454.3 underwent a dramatic outburst at all wavelengths from mm to X-rays. This prompted INTEGRAL observations, accomplished in 15-18 May 2005. The source was detected by the INTEGRAL instruments from 3 to 200 keV in a bright state (∼ 5 × 10-10 erg s-1 cm-2), at least a factor of 2-3 hi…
First observation of Mars with XMM-Newton. High resolution X-ray spectroscopy with RGS
Holmström, M.; Gunell, H.; Burwitz, V. +7 more
In the first observation of Mars with XMM-Newton, on 20-21 November 2003, this planet is clearly detected as an X-ray source. High resolution X-ray spectroscopy with the Reflection Grating Spectrometer (RGS) confirms that the X-ray radiation from Mars is composed of two different components: one due to fluorescent scattering of solar X-rays in its…
The broad-band spectrum of Cygnus X-1 measured by INTEGRAL
Goldoni, P.; Rodriguez, J.; Foschini, L. +9 more
The INTEGRAL satellite extensively observed the black hole binary Cygnus X-1 from 2002 November to 2004 November during calibration, open time and core program (Galactic Plane Scan) observations. These data provide evidence for significant spectral variations over the period. In the framework of the accreting black hole phenomenology, the source w…
Unveiling the nature of INTEGRAL objects through optical spectroscopy. III. Observations of seven southern sources
Palazzi, E.; Masetti, N.; Charles, P. A. +9 more
Context: . The detection, thanks to the INTEGRAL satellite, of a number of new hard X-ray sources calls for the identification of their nature by means of observations at longer wavelengths. Aims. In our continuing campaign to identify longer-wavelength counterparts of these newly-discovered hard X-ray sources detected by INTEGRAL, we observed the…
Nucleonic gamma-ray production in Vela X
Santangelo, A.; Aharonian, F.; Horns, D. +2 more
Context. The recently discovered extended very high energy gamma-ray (E>0.1~TeV=1011 eV) emission from at least three pulsar wind nebula systems (MSH 15-52, G18.0-07, and Vela X) could be hinting at a possibly new class of objects which is called in the following "TeV plerions". In some of these systems, particle acceleration could b…
On the propagation of brightening after filament/prominence eruptions, as seen by SoHO-EIT
Mason, H. E.; Isobe, H.; Tripathi, D.
Aims.To study the relationship between the propagation of brightening and erupting filaments/prominences in order to get some insight into the three-dimensional picture of magnetic reconnection.
Methods: .Analysis of the observations taken with the EIT (Extreme-ultraviolet Imaging Telescope) aboard SoHO (Solar and Heliospheric Observatory).
Modeling of PMS Ae/Fe stars using UV spectra
Blondel, P. F. C.; Djie, H. R. E. Tjin A.
Context: .Spectral classification of AeFe stars, based on visual observations, may lead to ambiguous conclusions.
Aims: . We aim to reduce these ambiguities by using UV spectra for the classification of these stars, because the rise of the continuum in the UV is highly sensitive to the stellar spectral type of A/F-type stars.
Methods: . …
XMM-Newton spectroscopy of the cluster of galaxies 2A 0335+096
Kaastra, J. S.; de Plaa, J.; Verbunt, F. +5 more
We present here the results of a deep (130 ks) XMM-Newton observation of the cluster of galaxies 2A 0335+096. The deep exposure allows us to study in detail its temperature structure and its elemental abundances. We fit three different thermal models and find that the multi-temperature wdem model fits our data best. We find that the abundance stru…
The VIMOS-VLT Deep Survey. Galaxy luminosity function per morphological type up to z = 1.2
Bondi, M.; Maccagni, D.; Ilbert, O. +47 more
Aims.We have computed the evolution of the rest-frame B-band luminosity function (LF) for bulge and disk-dominated galaxies since z=1.2.
Methods: .We use a sample of 605 spectroscopic redshifts with IAB≤ 24 in the Chandra Deep Field South from the VIMOS-VLT Deep Survey, 3555 galaxies with photometric redshifts from the COMBO-17 mult…
Extragalactic H_2O masers and X-ray absorbing column densities
Kadler, M.; Henkel, C.; Wilson, A. S. +4 more
Having conducted a search for the λ 1.3 cm (22 GHz) water vapor line towards galaxies with nuclear activity, large nuclear column densities or high infrared luminosities, we present H2O spectra for NGC 2273, UGC 5101, and NGC 3393 with isotropic luminosities of 7, 1500, and 400 L⊙. The H2O maser in UGC 5101 is by far the most luminous y…