Search Publications
Astrophysical lasers operating in optical Fe II lines in stellar ejecta of η Carinae
Johansson, S.; Letokhov, V. S.
After the discovery of space masers based on OH radicals (Weaver et al. \cite{Wea65}) and H2O (Cheung et al. \cite{Che69}) such microwave lasers have been found to work in more than 100 molecular species (Elitzur \cite{Eli92}; Townes \cite{Tow97}), as well as in highly excited H atoms (Strelnitski et al. \cite{Str96}). In the IR region …
The XMM-Newton view of NGC 6251
Brandt, W. N.; Mushotzky, R.; Gliozzi, M. +2 more
We report on the nuclear X-ray properties of the radio galaxy
A search for clusters and groups of galaxies on the line of sight towards 8 lensed quasars
Faure, C.; Alloin, D.; Kneib, J. P. +1 more
In this paper we present new ESO/VLT FORS1 and ISAAC images of the fields around eight gravitationally lensed quasars: CTQ 414, HE 0230-2130, LBQS 1009-0252, B 1030+074, HE 1104-1805, B 1359+154, H 1413+117 and HE 2149-2745. When available and deep enough, HST/WFPC2 data were also used to infer the photometric redshifts of the galaxies around the …
Quasi-simultaneous XMM-Newton and VLA observation of the non-thermal radio emitter HD 168112 (O5.5III(f+))
Blomme, R.; Rauw, G.; De Becker, M. +8 more
We report the results of a multiwavelength study of the non-thermal radio emitter HD 168112 (O5.5III(f+)). The detailed analysis of two quasi-simultaneous XMM-Newton and VLA observations reveals strong variability of this star both in the X-ray and radio ranges. The X-ray observations separated by five months reveal a decrease of the X-…
A large X-ray flare from the Herbig Ae star V892 Tau
Micela, G.; Favata, F.; Giardino, G. +1 more
We report the XMM-Newton observation of a large X-ray flare from the Herbig Ae star V892 Tau. The apparent low mass companion of V892 Tau, V892 Tau NE, is unresolved by XMM-Newton. Nevertheless there is compelling evidence from combined XMM-Newton and Chandra data that the origin of the flare is the Herbig Ae star V892 Tau. During the flare the X-…
X-ray spectroscopy of the Hertzsprung-gap giant star 31 Com, observed with XMM-Newton
Peres, G.; Maggio, A.; Scelsi, L. +1 more
We have analysed the XMM-Newton X-ray spectra of the yellow giant 31 Com with the aim of deriving information on the coronal structures of this archetypical Hertzsprung-gap star. To determine the emission measure distribution vs. temperature, EM(T), and the elemental abundances of the coronal plasma, with an accurate line-based approach, we have d…
The reprocessing features in the X-ray spectrum of the NELG MCG -5-23-16
Bianchi, S.; Balestra, I.; Matt, G.
We present results from the spectral analysis of the Seyfert 1.9 galaxy MCG -5-23-16, based on ASCA, BeppoSAX, Chandra and XMM-Newton observations. The spectrum of this object shows a complex iron Kα emission line, which is best modeled by a superposition of a narrow and a broad (possibly relativistic) iron line, together with a Compton reflection…
The X-ray emission mechanism in the protostellar jet HH 154
Orlando, S.; Bonito, R.; Peres, G. +2 more
We study the mechanism causing the X-ray emission recently detected in protostellar jets, by performing a detailed modeling of the interaction between a supersonic jet originating from a young stellar object and the ambient medium, for various values of density contrast, ν, between the ambient density and the jet, and of Mach number, M; radiative …
Evolution and magnetic topology of the M 1.0 flare of October 22, 2002
Aulanier, G.; Schmieder, B.; Del Zanna, G. +2 more
In this paper we analyse an M 1.0 confined flare observed mainly during its gradual phase. We use the data taken during a coordinated observational campaign between ground based instruments (THEMIS and VTT) and space observatories (SoHO/CDS and MDI, TRACE and RHESSI). We use these multi-wavelength observations to study the morphology and evolution…
Dust enshrouded star-forming activity in Arp 299
Le Floc'h, E.; Sauvage, M.; Vigroux, L. +4 more
We present mid-infrared spectro-imaging (5-16 µm) observations of the infrared luminous interacting system Arp 299 (= Mrk 171 = IC 694+NGC 3690) obtained with the ISOCAM instrument aboard ISO. Our observations show that nearly 40% of the total emission at 7 and 15 µm is diffuse, originating from the interacting disks of the galaxies. M…