ﻻ يوجد ملخص باللغة العربية
In this paper we explore the intermediate line region (ILR) by using the photoionisation simulations of the gas clouds present at different radial distances from the center, corresponding to the locations from BLR out to NLR in four types of AGNs. We let for the presence of dust whenever conditions allow for dust existence. All spectral shapes are taken from the recent multi-wavelength campaigns. The cloud density decreases with distance as a power law. We found that the slope of the power law density profile does not affect the line emissivity radial profiles of major emission lines: H${beta}$, He~II, Mg~II, C~III] ~and [O~III]. When the density of the cloud at the sublimation radius is as high as 10$^{11.5}$ cm$^{-3}$, the ILR should clearly be seen in the observations independently of the shape of the illuminating radiation. Moreover, our result is valid for low ionization nuclear emission regions of active galaxies.
The disk-wind scenario for the broad-line region (BLR) and toroidal obscuration in active galactic nuclei predicts the disappearance of the BLR at low luminosities. In accordance with the model predictions, data from a nearly complete sample of nearb
Although studying outflows in the host galaxies of AGN have become the forefront of extra-galactic astronomy in recent years, estimating the energy associated with these outflows have been a major challenge. Determination of the energy associated wit
The existence of intermediate-width emission line regions (IELRs) in active galactic nuclei has been discussed for over two decades. A consensus, however, is yet to be arrived at due to the lack of convincing evidence for their detection. We present
A two-components model for Broad Line Region (BLR) of Active Galactic Nuclei (AGN) has been suggested for many years but not widely accepted (e.g., Hu et al. 2008; Sulentic et al. 2000; Brotherton et al. 1996; Mason et al. 1996). This model indicates
We demonstrate a new technique for determining the physical conditions of the broad line emitting gas in quasars, using near-infrared hydrogen emission lines. Unlike higher ionisation species, hydrogen is an efficient line emitter for a very wide ran