A comparative study of the physical properties for a representative sample of Narrow and Broad-line Seyfert galaxies

Abstract

We present a comparative study of the physical properties of a homogeneous sample of 144 Narrow line Seyfert 1 (NLSy1) and 117 Broad-line Seyfert 1 (BLSy1) galaxies. These two samples are in a similar luminosity and redshift range and have optical spectra available in the 16${}^{th}$ data release of Sloan Digital Sky Survey (SDSS-DR16) and X-ray spectra in either XMM-NEWTON or ROSAT. Direct correlation analysis and a Principal Component Analysis (PCA) have been performed using ten observational and physical parameters obtained by fitting the optical spectra and the soft X-ray photon indices as another parameter. We confirm that the established correlations for the general quasar population hold for both types of galaxies in this sample despite significant differences in the physical properties. We characterize the sample also using the line shape parameters, namely the asymmetry and kurtosis indices. We find that the fraction of NLSy1 galaxies showing outflow signatures, characterized by blue asymmetries, is higher by a factor of about 3 compared to the corresponding fraction in BLSy1 galaxies. The presence of high iron content in the broad-line region of NLSy1 galaxies in conjunction with higher Eddington ratios can be the possible reason behind this phenomenon. We also explore the possibility of using asymmetry in the emission lines as a tracer of outflows in the inner regions of Active Galactic Nuclei. The PCA results point to the NLSy1 and BLSy1 galaxies occupying different parameter spaces, which challenges the notion that NLSy1 galaxies are a subclass of BLSy1 galaxies.

15 pages, 11 figures, Accepted for publication in MNRAS

References in corpus (21)

• A Catalog of Quasar Properties from SDSS DR7
• The Sloan Digital Sky Survey Quasar Catalog: Sixteenth Data Release
• The diversity of quasars unified by accretion and orientation
• The AGN Black Hole Mass Database
• A Comprehensive Study of 2 000 Narrow Line Seyfert 1 Galaxies from the Sloan Digital Sky Survey: I. The Sample
• Broad-line Balmer Decrements in Blue Active Galactic Nuclei
• Space Telescope and Optical Reverberation Mapping Project. I. Ultraviolet Observations of the Seyfert 1 Galaxy NGC 5548 with the Cosmic Origins Spectrograph on Hubble Space Telescope
• Dust inflated accretion disc as the origin of the Broad Line Region in Active Galactic Nuclei
• Are the black hole masses in Narrow Line Seyfert 1 galaxies actually small?
• Modeling reverberation mapping data I: improved geometric and dynamical models and comparison with cross-correlation results
• A spectroscopic analysis of a sample of narrow-line Seyfert 1 galaxies selected from the Sloan Digital Sky Survey
• Failed radiatively Accelerated Dusty Outflow model of the Broad Line Region in Active Galactic Nuclei. I. Analytical solution
• What does Civλ1549 tell us about the physical driver of the Eigenvector Quasar Sequence?
• Stratified disc wind models for the AGN broad-line region: ultraviolet, optical and X-ray properties
• A Suzaku sample of unabsorbed narrow-line and broad-line Seyfert 1 galaxies: I. X-ray spectral properties
• A comparison of hard X-ray photon indices and iron \ka emission lines in X-ray luminous narrow- and broad-line Seyfert 1 galaxies
• Statistical multifrequency study of narrow-line Seyfert 1 galaxies
• Exploring the Diversity of Type 1 Active Galactic Nuclei Identified in SDSS-IV/SPIDERS
• An extended size-luminosity relation for the reverberation-mapped AGNs: the role of the accretion rate
• A comparison of X-ray photon indices among the narrow and broad-line Seyfert 1 galaxies
• Intra-night optical variability of $\gamma -$ray detected narrow-line Seyfert 1 galaxies