Fermi-LAT detection of A new starburst galaxy candidate: IRAS 13052-5711

TL;DR

This paper reports the discovery of IRAS 13052-5711 as the most distant starburst galaxy candidate detected by Fermi-LAT, with characteristics similar to known SBGs, and discusses its spectral properties and potential emission mechanisms.

Contribution

First detection of a distant starburst galaxy candidate using Fermi-LAT data, expanding the known population and providing insights into its gamma-ray emission and star formation rate.

Findings

Significance level of 6.55σ in 0.1-500 GeV band

Star formation rate estimated at 29.38 M_sun/yr

Gamma-ray luminosity deviates from empirical IR-gamma correlation

Abstract

A likely starburst galaxy (SBG), IRAS 13052-5711, which is the most distant SBG candidate discovered to date, was found by analyzing 14.4 years of data from the Fermi large-area telescope (Fermi-LAT). This SBG's significance level is approximately 6.55$\sigma$ in the 0.1-500 GeV band. Its spatial position is close to that of 4FGL J1308.9-5730, determined from the Fermi large telescope fourth-source Catalog (4FGL). Its power-law spectral index is approximately 2.1, and its light curve (LC) for 14.4 years has no significant variability. These characteristics are highly similar to those of SBGs found in the past. We calculate the SBG's star formation rate (SFR) to be 29.38 $\rm M_{\odot}\ yr^{-1}$, which is within the SFR range of SBGs found to date. Therefore, IRAS 13052-5711 is considered to be a likely SBG. In addition, its 0.1-500 GeV luminosity is (3.28 $\pm$ 0.67) $\times 10^{42}\ \rm erg\ s^{-1}$, which deviates from the empirical relationship of the $\gamma$-ray luminosity and the total infrared luminosity. We considered a hadronic model to explain the GeV spectrum of IRAS 13052-5711.