GeV $\gamma$-ray emission from M33 and Arp~299

Abstract

Star-forming galaxies are huge reservoirs of cosmic rays (CRs) and these CRs convert a significant fraction of their energy into $\gamma$-rays by colliding with the interstellar medium (ISM). Several nearby star-forming galaxies have been detected in GeV-TeV $\gamma$-rays. It is also found that the $\gamma$-ray luminosities in 0.1-100 GeV correlate well with indicators of star formation rates of the galaxies, such as the total infrared (IR) luminosity. In this paper, we report a systematic search for possible $\gamma$-ray emission from galaxies in the IRAS Revised Bright Galaxies Sample, using 11.4 years of $\gamma$-ray data taken by the Fermi Large Area Telescope (LAT). Two new galaxies, M33 and Arp 299, are detected significantly. The two galaxies are consistent with the empirical correlation between the $\gamma$-ray luminosity and total infrared luminosity, suggesting that their $\gamma$-ray emissions should mainly originate from CRs interacting with ISM. Nevertheless, there is a tentative evidence that the flux of the $\gamma$-ray emission from Arp~299 is variable. If the variability is true, part of the emission from Arp 299 should originate from the obscured AGN in this interacting galaxy system. In addition, we find that the $\gamma$-ray excess from M33 is located at the northeast region of the galaxy, where a supergiant H II region, NGC604, resides. This indicates that some bright star-forming regions in spiral galaxies could play a dominant role in the galaxy in producing $\gamma$-ray emission.

9 pages, 9 figures, 2 tables; ApJ accepted

References in corpus (12)

• The Mean Star Formation Rate of X-ray selected Active Galaxies and its Evolution from z=2.5: Results from PEP-Herschel
• The Starburst Contribution to the Extra-Galactic Gamma-Ray Background
• Core-collapse supernovae missed by optical surveys
• Fermi Large Area Telescope observations of Local Group galaxies: Detection of M31 and search for M33
• The $\gamma$-ray Emission of Star-Forming Galaxies
• Observations of M31 and M33 with the Fermi Large Area Telescope: a galactic center excess in Andromeda?
• High-ionization Fe K emission from luminous infrared galaxies
• Discovery of GeV emission from the direction of the luminous infrared galaxy NGC 2146
• Are Diffuse High Energy Neutrinos and Gamma-Rays from Starburst Galaxies Observable?
• Search for $\gamma$-ray emission from dark matter particle interactions from Andromeda and Triangulum Galaxies with the Fermi Large Area Telescope
• A Focused, Hard X-ray Look at Arp 299 with NuSTAR
• A serendipitous discovery of GeV gamma-ray emission from supernova 2004dj in a survey of nearby star-forming galaxies with Fermi-LAT

Cited by in corpus (14)

• The Panchromatic Hubble Andromeda Treasury: Triangulum Extended Region (PHATTER) I. Ultraviolet to Infrared Photometry of 22 Million Stars in M33
• Dark Matter Interpretation of the Fermi-LAT Observations Toward the Outer Halo of M31
• Cosmic rays across the star-forming galaxy sequence. I: Cosmic ray pressures and calorimetry
• Jet Properties of Compact Steep-Spectrum Sources and an Eddington-Ratio-Driven Unification Scheme of Jet Radiation in Active Galactic Nuclei
• Characterising the signatures of star-forming galaxies in the extra-galactic $\gamma$-ray background
• Highly Variable $\gamma$-Ray Emission of CTD 135 and Implications for its Compact Symmetric Structure
• On the Gamma-Ray Emission of the Andromeda Galaxy M31
• Prospects of newly detecting nearby star-forming galaxies by the Cherenkov Telescope Array
• Fermi-LAT detection of A new starburst galaxy candidate: IRAS 13052-5711
• Identifying the Gamma-ray Emission of the Nearby Galaxy M83
• Prospects for annihilating dark matter from M31 and M33 observations with the Cherenkov Telescope Array
• Monitoring the X-ray Variability of Bright X-ray Sources in M33
• Possible Origin of a Newly Discovered GeV Gamma-ray Source Fermi J1242.5+3236
• Hunting Star-Forming Galaxies in the Gamma-Ray Domain