8 papers · 1 filter
The symbiotic star CH Cygni. II. The broad Ly alpha emission line explained by shocks
M. Contini, R. Angeloni, P. Rafanelli
Context. In 1985, at the end of the active phase 1977-1986, a broad (4000 km/s) Ly alpha line appeared in the symbiotic system CH Cygni that had never been observed previously. Aim…
The solar photospheric abundance of europium. Results from CO5BOLD 3-D hydrodynamical model atmospheres
A. Mucciarelli, E. Caffau, B. Freytag +2
Context. Europium is an almost pure r-process element, which may be useful as a reference in nucleocosmochronology. Aims. To determine the photospheric solar abundance using CO5BOL…
Constraining global parameters of accreting black holes by modeling magnetic flares
R. W. Goosmann, M. Mouchet, M. Dovciak +3
We present modeling results for the reprocessed radiation expected from magnetic flares above AGN accretion disks. Relativistic corrections for the orbital motion of the flare and…
Constraints on a strong X-ray flare in the Seyfert galaxy MCG-6-30-15
R. W. Goosmann, B. Czerny, V. Karas +3
We discuss implications of a strong flare event observed in the Seyfert galaxy MCG-6-30-15 assuming that the emission is due to localized magnetic reconnection. We conduct detailed…
Modeling time delays in the X-ray spectrum of the Seyfert galaxy MCG-6-30-15
R. W. Goosmann, B. Czerny, V. Karas +1
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…
C,N,O in lambda Boo stars and in composite spectra
R. Faraggiana, P. Bonifacio
The selective abundance of C, N, O (almost solar) with respect to that of other elements (underabundant) in lambda Boo stars has been interpreted as a characteristic peculiarity of…