Fermi-LAT Detection of a New Starburst Galaxy Candidate: IRAS 13052-5711

Abstract

A likely starburst galaxy (SBG), IRAS 13052–5711, which is the most distant SBG candidates discovered to date, was found by analyzing 14.4 yr of data from the Fermi large-area telescope. This SBG’s significance level is approximately 6.55 σ 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 for 14.4 yr 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 M _⊙ 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 ± 0.67) × 10 ^42 erg s ^−1 , which deviates from the empirical relationship of the γ -ray luminosity and the total infrared luminosity. We considered a hadronic model to explain the GeV spectrum of IRAS 13052-5711.

Keywords

• Starburst galaxies
• Gamma-ray astronomy