Broad Emission Line Flux Research Articles

Photometry and Spectrophotometry of the Seyfert Galaxy MRK 509 over 23 Years Photometry And Spectrophotometry Of The Seyfert Galaxy Mrk 509

In the time period from 1972-1993, the Seyfert 1 galaxy Mrk 509 showed large variations of its optical continuum and broad emission line fluxes. The broad Hα and Hγ emission lines have approximately the same profiles, which retain their shape during flux variations. The relationship between the continuum and emission line fluxes varies with time. The spectral energy distribution of the variable continuum based on UBVRI data has the form lgF(ν) ≈ αlgν, with the dereddened α = -0.60.

Does the inner broad-line region DIM down when the power turns up?

The temporal correlations of continuum and broad emission-line fluxes from the Seyfert galaxy NGC 5548 as measured during the 1989 monitoring campaign show two related peculiarities: first, some of the crosscorrelations of line and continuum flux appear steeper on the negative time lag side than the continuum autocorrelation itself; then, the autocorrelation of the line flux is sometimes more sharply peaked than the continuum autocorrelation function. These are here interpreted as evidence that conditions in the inner part of the broad-line region are such that some emission lines decrease in intensity as the continuum strengthens.

Short timescale broad emission-line flux variability in high-luminosity active galactic nuclei

The standard model of AGN suggests that the broad-line regions of high-luminosity AGN should be so large that any variability in the broad emission-line fluxes should be on timescales of about 2-4 yr or more. Spectrophotometric observations of eight radio-quiet QSOs over a period of 1 yr revealed definite H-beta flux variability in one of these objects and possibly in two others. This may be an indication that the BLRs in high-luminosity AGNs are much smaller than those predicted by the standard model, as is apparently the case in Seyfert galaxies. 28 refs.