The U.S. Naval Observatory VLBI Spectroscopic Catalog

TL;DR

This paper presents a comprehensive spectroscopic catalog of 1,014 ICRF3 objects, providing key emission line, continuum, and black hole mass data, enhancing understanding of AGNs used in celestial reference frames.

Contribution

It introduces a new catalog with detailed spectroscopic parameters and black hole mass estimates for ICRF3 AGNs, utilizing advanced fitting techniques and consistent scaling relationships.

Findings

Catalog includes emission line and continuum parameters for 1,014 AGNs.

Black hole mass estimates are derived using multiple line width scaling relationships.

Provides insights into the properties and characteristics of ICRF3 AGNs.

Abstract

Despite their importance for astrometry and navigation, the active galactic nuclei (AGNs) that comprise the International Celestial Reference Frame (ICRF) are relatively poorly understood, with key information such as their spectroscopic redshifts, AGN spectral type, and emission/absorption line properties generally missing from the literature. Using updated, publicly available, state-of-the-art spectroscopic fitting code optimized for the spectra of AGNs from low to high redshift, we present a catalog of emission line and spectral continuum parameters for 1,014 unique ICRF3 objects with single-fiber spectra from the Sloan Digital Sky Survey DR16. We additionally present black hole virial mass scaling relationships that use H$\alpha$-, H$\beta$-, Mg II-, and C IV-based line widths, all consistent with each other, which can be used in studies of radio-loud objects across a wide range of redshifts, and we use these scaling relationships to provide derived properties such as black hole masses and bolometric luminosities for the catalog. We briefly comment on these properties for the ICRF objects, as well as their overall spectroscopic characteristics.