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12 papers found.
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The electron impact broadening parameters in hot star atmospheres: Mn II, Mn III, Ga III, Ge III and Ge IV lines

The electron - impact line widths and shifts for 16 Mn II, 3 Mn III, 10 Ga III, 8 Ge III and 14 Ge IV multiplets, have been considered within a modified semiempirical approach. Moreover, using a semiclassical approach, we have considered electron-, pro ton-, and He III-im pact line widths and shifts for 3 Ge IV multiplets. The obtained results have been compared with other...

Spectrophotometric variability of quasars caused by lensing of diffuse massive substructure: consequences on flux anomaly and precise astrometric measurements

We investigate the spectrophotometric variability of quasars due to lensing of small mass substructure (from several tens to several hundreds solar masses). The aim of this paper is to explore the milli/microlensing influence on the flux anomaly observed between images of a lensed quasar in different spectral bands and the possible influence of small mass structure lensing of non...

The influence of gravitational lensing on the spectra of lensed quasi-stellar objects

We consider the influence of (milli/micro)lensing on the spectra of lensed quasi-stellar objects (QSOs). We propose a method for the observational detection of microlensing in the spectra of lensed QSOs and apply it to the spectra of three lensed QSOs (PG 1115+080, Q1413+117 and Q0957+561) observed with the Hubble Space Telescope. We find that the flux ratio between images A1 and...

Microlensing of the X-ray, UV and optical emission regions of quasars: simulations of the time-scales and amplitude variations of microlensing events

We consider the influence of microlensing on different spectral bands of lensed QSOs. We assumed that the emitting X-ray, ultraviolet (UV) and optical regions are different in size, but that the continuum emission in these spectral bands is originating from an accretion disc. Estimations of the time-scales for microlensing and flux amplification in different bands are given. We...

Contribution of a disc component to single-peaked broad lines of active galactic nuclei

We study the disc emission component hidden in the single-peaked broad emission lines (BELs) of active galactic nuclei. We compare the observed broad lines from a sample of 90 Seyfert 1 spectra taken from the Sloan Digital Sky Survey with simulated line profiles. We consider a two-component broad line region model where an accretion disc and a surrounding non-disc region with...

The flux ratio of the [O iii] λλ5007, 4959 lines in AGN: comparison with theoretical calculations

By taking into account the relativistic corrections to the magnetic dipole operator, the theoretical [O iii] 5006.843/4958.911 line intensity ratio of 2.98 is obtained. In order to check this new value using the active galactic nuclei (AGN) spectra, we present the measurements of the flux ratio of the [O iii] λλ4959, 5007 emission lines for a sample of 62 AGN, obtained from the...

Long-term variability of the optical spectra of NGC 4151 - II. Evolution of the broad Hα and Hβ emission-line profiles

Aims. We present the results of a long-term monitoring (11 years, between 1996 and 2006) of Hα and Hβ line variations of the active galactic nucleus of NGC 4151.Methods. High quality spectra (S/N > 50 and R≈ 8 Å) of Hα and Hβ were investigated. During monitoring period, we analyzed line profile variations. Comparing the line profiles of Hα and Hβ, we studied different details...

Complex emission line region of Mrk 817

In this work, we study the physical and kinematical properties of the emission line region of the Seyfert 1.5 galaxy Mrk 817 using three sets of observations, among which are high-resolution spectra obtained with the Isaac Newton Telescope (INT) on the Canary Islands. We find that, in Mrk 817, the narrow and broad emission lines (NELs and BELs, respectively) are very complex...

The gas kinematics in the Mrk 533 nucleus and circumnuclear region: a gaseous outflow

We present an analysis of 3D spectra of Mrk 533, observed with the integral-field spectrograph MultiPupil Fiber Spectrograph (MPFS) and using the Fabry-Perot Interferometer (FPI) of the Special Astrophysical Observatory of the Russian Academy of Sciences (SAO RAS) 6-m telescope. We found emissions of gas from the active type 2 Seyfert nucleus in the centre and also from the H ii...

Spectral optical monitoring of 3C 390.3 in 1995–2007 - I. Light curves and flux variation in the continuum and broad lines

Context. We present the results of the long-term (1995–2007) spectral monitoring of the broad-line radio galaxy 3C 390.3, a well known AGN with double-peaked broad emission lines, usually assumed to be emitted from an accretion disk.Aims. To explore dimensions and structure of the BLR, we analyze the light curves of the broad Hα and Hβ line fluxes and the continuum flux. To...

The influence of microlensing on spectral line shapes generated by a relativistic accretion disc

We study the influence of gravitational microlensing on the spectral line profiles originating from a relativistic accretion disc. Using the Chen & Halpern model for the disc, we show the noticeable changes that microlensing can induce in the line shape when the Einstein radius associated with the microlens is of a size comparable to that of the accretion disc. Of special...

The electron impact broadening parameters in hot star atmospheres: Mn II, Mn III, Ga III, Ge III and Ge IV lines

The electron - impact line widths and shifts for 16 Mn II, 3 Mn III, 10 Ga III, 8 Ge III and 14 Ge IV multiplets, have been considered within a modified semiempirical approach. Moreover, using a semiclassical approach, we have considered electron-, pro ton-, and He III-im pact line widths and shifts for 3 Ge IV multiplets. The obtained results have been compared with other...