# A comprehensive and uniform sample of broad-line active galactic nuclei from the SDSS DR7

## TL;DR

This paper presents a large, homogeneous catalog of 14,584 broad-line AGNs from SDSS DR7, with detailed spectral analysis and derived properties, enabling extensive studies of low-redshift AGN characteristics.

## Contribution

The creation of the largest, uniformly selected low-redshift broad-line AGN catalog with detailed spectral measurements and derived physical parameters.

## Key findings

- Broad Hα luminosities range from 10^{38.5} to 10^{44.3} erg s^{-1}
- Black hole masses span from 10^{5.1} to 10^{10.3} solar masses
- Eddington ratios vary from -3.3 to 1.3 in log scale

## Abstract

A new, complete sample of 14,584 broad-line AGNs at $z<0.35$ is presented, which are uncovered homogeneously from the complete database of galaxies and quasars observed spectroscopically in the Sloan Digital Sky Survey Seventh Data Release. The stellar continuum is properly removed for each spectrum with significant host absorption line features, and careful analyses of the emission-line spectra, particularly in the H$\rm \alpha$ and H$\rm \beta$ wavebands, are carried out. The broad Balmer emission line, particularly, H$\rm \alpha$, is used to indicate the presence of an AGN. The broad H$\rm \alpha$ lines have luminosities in a range of $10^{38.5}$-$10^{44.3}$ erg s$^{-1}$, and line widths (FWHMs) of 500-34,000 km s$^{-1}$. The virial black hole masses, estimated from the broad line measurements, span a range of $10^{5.1}$-$10^{10.3}$ $M_\odot$, and the Eddington ratios vary from $-3.3$ to $1.3$ in logarithmic scale. Other quantities such as multi-wavelength photometric properties and flags denoting peculiar line profiles are also included in this catalog. We describe the construction of this catalog and briefly discuss its properties. The catalog is publicly available online. This homogeneously selected AGN catalog, along with the accurately measured spectral parameters, provide the most updated, largest AGN sample data, which will enable further comprehensive investigations of the properties of the AGN population in the low-redshift universe.