Related papers: [O III] emission line in narrow-line Seyfert 1 gal…
It has been proposed that the width of the narrow [O III] 5007 emission line can be used as a surrogate for the stellar velocity dispersion in active galaxies. This proposition is tested using the SDSS EDR spectra of 107 low-redshift…
This work studies the optical emission line properties and physical conditions of the narrow line region (NLR) of seven narrow-line Seyfert 1 galaxies (NLS1). Our results show that the flux carried out by the narrow component of H-beta is,…
Controversy regarding whether Narrow Line Seyfert 1 galaxies (NLS1s) follow the same black hole --- galactic bulge relation as normal galaxies has been raised by Mathur et al. (2001) and Ferrarese et al. (2001). In this paper, the…
Many active galactic nuclei (AGN) and particularly narrow-line Seyfert 1 (NLS1) galaxies, usually exhibit blueshifts and blue wings in several emission lines, which are mainly associated with outflows and strong winds. In order to study the…
We have compiled a list of 83 objects classified as Narrow-Line Seyfert 1 galaxies (NLS1s) or known to have a broad Balmer component narrower than 2000 km/s. Out of these, 19 turned out to have been spectroscopically misidentified in…
For a sample of $\sim$80 local ($0.02 \leq z \leq 0.1$) Seyfert-1 galaxies with high-quality long-slit Keck spectra and spatially-resolved stellar-velocity dispersion ($\sigma_{\star}$) measurements, we study the profile of the…
Several authors recently explored the Black-Hole mass (M_BH) vs. stellar velocity dispersion (sigma_*) relationship for Narrow Line Seyfert 1 galaxies (NLS1s). Their results are more or less in agreement and seem to indicate that NLS1s fill…
We have explored the relationship between the [O III] $\lambda$5007 and the 2--10 keV luminosities for a sample of Broad- and Narrow-Line Seyfert 1 galaxies (BLSy1 and NLSy1, respectively). We find that both types of Seyferts span the same…
We used multi-component profiles to model H$\beta$ and [O III]$\lambda \lambda $4959,5007 lines for SDSS J143030.22-001115.1, a narrow-line Seyfert 1 galaxy (NLS1) in a sample of 150 NLS1s candidates selected from the Sloan Digital Sky…
We present the results of a Hubble Space Telescope (HST) survey of extended [OIII] emission in a sample of 60 nearby Seyfert galaxies (22 Seyfert 1's and 38 Seyfert 2's), selected by mostly isotropic properties. The comparison between the…
We investigate the radial velocity difference between the narrow emission-line components of [O III] $\lambda$ 5007 and H$\beta$ in a sample of 150 SDSS NLS1s. Seven "blue outliers" with [O III] blueshifted by more than 250 \kms are found.…
The spectra of active galactic nuclei usually exhibit wings in some emission lines, such as [OIII]$\lambda\lambda$5007,4959, with these wings generally being blueshifted and related to strong winds and outflows. The aim of this work was to…
We have studied the location of narrow-line Seyfert 1 (NLS1) galaxies and broad-line Seyfert 1 (BLS1) galaxies on the M_BH - sigma relation of non-active galaxies. We find that NLS1 galaxies as a class - as well as the BLS1 galaxies of our…
We present a Hubble Space Telescope (HST) survey of extended [OIII] emission for a sample of 60 Seyfert galaxies (22 Seyfert 1's and 38 Seyfert 2's), selected based on their far infrared properties. The observations for 42 of these galaxies…
It is not yet well known whether narrow line Seyfert 1 (NLS1) galaxies follow the $M_{BH} - \sigma_{\star}$ relation found for normal galaxies. Emission lines, such as [SII] or [OIII]$\lambda$5007, have been used as a surrogate of the…
The narrow [O III] 4959, 5007 emission-line fluxes in the spectrum of the well-studied Seyfert 1 galaxy NGC 5548 are shown to vary with time. From this we show that the narrow line-emitting region has a radius of only 1-3 pc and is denser…
We revisited the spectroscopic characteristics of narrow-line Seyfert 1 galaxies (NLS1s) by analysing a homogeneous sample of 296 NLS1s at redshift between 0.028 and 0.345, extracted from the Sloan Digital Sky Survey (SDSS-DR7) public…
We present a study of reddening and absorption towards the Narrow Line Regions (NLR) in active galactic nuclei (AGN) selected from the Revised Shapley-Ames, 12mu, and Swift/Burst Alert Telescope samples. For the sources in host galaxies…
We present the results of a narrow-band survey of QSO fields at redshifts that place the [OIII](5007) emission line in the 1% 2.16micron filter. We have observed 3 square arcminutes and detected one emission line candidate object in the…
The second moment of the H$\beta$ emission line is calculated for 329 narrow line Seyfert 1 galaxies (NLS1s) selected from the Sloan Digital Sky Survey (SDSS), which is used to calculate the central supermassive black hole (SMBHs) mass of…