SIMBAD references

The variations of the [OIII]λ5007 line profile in NGC 5548 are examined from CCD spectra obtained at the Ohio State University and Crimean Astrophysical Observatory in December 1988 - October 1994. We have found the total flux of [OIII]λ5007 line to be variable, so the spectral calibration based on the assumption of non-variability of [OIII]λ5007 line is not absolutely correct. The variations are much more pronounced in the far wings of the line profile (∼1100km/s). Assuming the central part of the line profile is non-variable, we analyzed the variations of the red and blue wings relative to the profile center. We have found that these variations can be explained in terms of a reaction to the ionizing radiation changes with a transfer function spreading up to several hundred days. Perhaps, the ``real'' constant flux is localized in the narrow [OIII] line which belongs to the NLR and has a transfer function of about several hundred years, while the broad wings are emitted from the outer BLR. These wings may belong to FeIIλ5018 and/or [OIII]λ5007. The transfer function of the blue wing is narrower, with a peak shifted to the zero lag by ∼200 days relative to the transfer function of the red wing. Both wings, and especially the blue wing, show weak reaction near the zero lag. These facts must exclude both pure radial and round motion, but may suggest a lack of emitting gas near the line of sight and the presence of an outflow component. The FeIIλ5169 line shows similar behavior to the [OIII]λ5007 wings. It confirms FeIIλ5018 is the main contributor to the [OIII] wings or that the broad [OIII] is emitted at the same distance from the central engine as the FeII. The assumption about the presence of ``short'' and ``long'' lag spectral components, one of which varies similarly to the Hβ line and the other similarly to the [OIII] λ 5007 wings, permits us to separate these components. The decomposition of the spectra shows that all observed FeII multiplets have a high lag value of the order of several hundred days, pointing to the typical size of the region which emits these lines. The decomposition also shows that there is a short lag component in the red wing of [OIII]λ5007 line. According to the centroid of this line (≃5032Å) it may be identified with the SIIIλ5041,5056 or HeIλ5016,5048.