Motivated by recent work indicating that the UV continuum in AGN may be produced by reradiation of energy absorbed from X-rays irradiating an accretion disk, we present a calculation of the vertical structures and ultraviolet spectra of X-ray irradiated accretion disks around massive non-rotating black holes. After finding the radial dependence of vertically-integrated quantities for these disk...

copper vanadate nanostructures were prepared via ex-situ precipitation approach in presence of schiff-base ligand (n,n׳ -buthylenebis(acetylacetone iminato)dianion = acacbn) as a new capping agent. the effect of different cu sources and ph on the size, morphology and size distribution of copper vanadate nanostructures was investigated. the as-prepared products were characterized using x-ray dif...

Polpyrrole (PPy)/Ag nanocomposites were successfully synthesized at the interface of water and ionic liquid by one-step UV-induced polymerization. Highly dispersed PPy/Ag nanoparticles were obtained by controlling the experimental conditions. The results of Fourier-transform infrared spectroscopy, X-ray diffraction, transmission electron microscopy and X-ray photoelectron spectroscopy revealed ...

We analyse the data from the optical/IUE observational campaign of the Seyfert galaxy NGC 5548 in the context of 10 phenomenological models. On the basis of the optical/UV data as well as constraints from the X-ray observations we can favour one model of the nucleus: an accretion disc with an inner radius cutoff surrounded by a hot corona. The second acceptable model for optical/UV data is a di...

X-ray crystallography at third-generation synchrotron sources permits tremendous insight into the three-dimensional structure of macromolecules. Additional information is, however, often required to aid the transition from structure to function. In situ spectroscopic methods such as UV-Vis absorption and (resonance) Raman can provide this, and can also provide a means of detecting X-ray-induced...

zno and zno:mn nanocrystals synthesized via reverse micelle method. the size, band gap, urbach energy, optical constants and penetration depth of nanocrystals were calculated by uv-vis spectroscopy data. the surface morphology was studied with the use of scanning electron microscope (sem). moreover the samples exposed to gama ray source of 60co and their thermoluminescence properties were also ...

Recent work in the design of soft X -ray and extreme UV spectrographs has identified a new class of reflection gratings whose aberrations do not increase at grazing incidence. To achieve this characteristic, the groove spacings are varied in a continuous manner across a plano grating aperture. Ray traces of the concentric groove grating, the oriental fan grating and variations illustrate their ...

High-velocity outflows from AGN are a well-known phenomena in terms of the Broad Absorption Lines seen in the UV/optical. More recently, similar, possibly related, outflows have been reported in the X-ray. The most extreme example is seen in the nearby, luminous QSO PDS 456, which displays a massive, high velocity (50000 km s), high-ionization X-ray outflow of 10M⊙ yr . Here we present the UV s...

ZnS nanoparticles of different size have been synthesized using a colloidal particles method. ZnS nanoparticles prepared with capping agent (mercaptoethanol) then were characterized using X-ray diffraction (XRD) and UV-Vis spectroscopy. The particle size of the nanoparticles calculated from the XRD patterns has been found in the range 1.85-2.44nm. Absorption spectra have been obtained using UV-...

We have undertaken near-continuous monitoring of the Seyfert 1 galaxy NGC 7469 in the X-ray with RXTE over a ∼ 30 d baseline. The source shows strong variability with a root-mean-square (rms) amplitude of ∼ 16 per cent, and peak–to–peak variations of a factor of order 2. Simultaneous data over this period were obtained in the ultraviolet (UV) using IUE, making this the most intensive X-ray UV/X...