Spectral properties of quasars from Sloan Digital Sky Survey data release 14: The catalog

TL;DR

This paper provides a comprehensive analysis of spectral properties for over half a million quasars from SDSS-DR14, estimating black hole masses, accretion rates, and emission line parameters, and making the catalog publicly available.

Contribution

It offers a homogeneous analysis of SDSS quasar spectra, deriving spectral properties and black hole masses for a large sample, with an extensive publicly accessible catalog.

Findings

Correlation patterns consistent with previous smaller studies

Rare high-mass, high-accretion quasars identified

Spectral property distributions across the sample analyzed

Abstract

We present measurements of the spectral properties for a total of 526,265 quasars, out of which 63% have continuum S/N$>3$ pixel$^{-1}$, selected from the fourteenth data release of the Sloan Digital Sky Survey (SDSS-DR14) quasar catalog. We performed a careful and homogeneous analysis of the SDSS spectra of these sources, to estimate the continuum and line properties of several emission lines such as H${\alpha}$, H${\beta}$, H${\gamma}$, Mg \textsc{ii}, C \textsc{iii]}, C \textsc{iv} and Ly${\alpha}$. From the derived emission line parameters, we estimated single-epoch virial black hole masses ($M_{\mathrm{BH}}$) for the sample using H${\beta}$, Mg \textsc{ii} and C \textsc{iv} emission lines. The sample covers a wide range in bolometric luminosity ($\log L_{\mathrm{bol}}$; erg s$^{-1}$) between 44.4 and 47.3 and $\log M_{\mathrm{BH}}$ between 7.1 and 9.9 $M_{\odot}$. Using the ratio of $L_{\mathrm{bol}}$ to the Eddington luminosity as a measure of the accretion rate, the logarithm of the accretion rate is found to be in the range between $-$2.06 and 0.43. We performed several correlation analyses between different emission line parameters and found them to match with that known earlier using smaller samples. We noticed that strong Fe \textsc{ii} sources with large Balmer line width, and highly accreting sources with large $M_{\mathrm{BH}}$ are rare in our sample. We make available online an extended and complete catalog that contains various spectral properties of 526,265 quasars derived in this work along with other properties culled from the SDSS-DR14 quasar catalog.