A comparative study of ultraluminous infrared galaxies in the IRAS and SDSS Surveys

TL;DR

This study cross-matched IRAS and SDSS data to identify and analyze 283 ULIRGs, revealing their interaction features, high AGN prevalence, and similarities to NLS1s, providing a comprehensive understanding of their properties and evolution.

Contribution

It introduces a reliable cross-matching method to identify ULIRGs and provides new insights into their interaction features, AGN activity, and evolutionary links with NLS1s.

Findings

Identified 283 reliable ULIRGs, including 102 new detections.

Approximately 40% show interaction features, rising to 92% for z<0.1.

Over 58% host an AGN, twice the rate from infrared colors.

Abstract

We present a comprehensive study of Ultraluminous Infrared Galaxies (ULIRGs), leveraging data from the IRAS Faint Source Catalogue (FSC) and the spectroscopic catalog in the Sloan Digital Sky Survey (SDSS) DR16. Our meticulous cross-matching technique significantly enhances the reliability of ULIRG identification, resulting in the identification of 283 reliable ULIRGs, including 102 new detections, while discarding 120 previously reported false sources. Covering a redshift range of $z = 0.018 - 0.996$, with a median redshift of $\bar{z} = 0.259$, our uniform sample reveals apparent interaction features in approximately 40\% of ULIRGs, increasing to 92\% for those with $z < 0.1$. Through optical spectra analysis, it is indicated that over 58\% of ULIRGs host an AGN, which is twice as high as the detections based solely on infrared colors. Moreover, a pronounced excess of radio emissions associated with AGN activity results in a steeper radio-far-infrared correlation. Notably, Type I ULIRGs exhibit properties similar to those of narrow-line Seyfert 1 galaxies (NLS1s), with an elevated incidence rate of \ion{Mg}{2} BALs (16.7\%), surpassing that of typical optically selected quasars by over tenfold, consistent with current evolutionary models. We anticipate that forthcoming telescopes such as the China Space Station Telescope (CSST) and Leighton Chajnantor Telescope (LCT) will provide deeper insights into ULIRG morphology, dust distribution, molecular gas, and AGN activity.