Interpreting the relation between the gamma-ray and infrared luminosities of star-forming galaxies

Abstract

It has been found that there is a quasi-linear scaling relationship between the gamma-ray luminosity in GeV energies and the total infrared luminosity of star-forming galaxies, i.e. $L_{\gamma }\propto L_{\mathrm{IR}}^{\alpha }$ with $\alpha \simeq 1$. However, the origin of this linear slope is not well understood. Although extreme starburst galaxies can be regarded as calorimeters for hadronic cosmic ray interaction and thus a quasi-linear scaling may hold, it may not be the case for low star-formation-rate (SFR) galaxies, as the majority of cosmic rays in these galaxies are expected to escape. We calculate the gamma-ray production efficiency in star-forming galaxies by considering realistic galaxy properties, such as the gas density and galactic wind velocity in star-forming galaxies. We find that the slope for the relation between gamma-ray luminosity and the infrared luminosity gets steeper for low infrared luminosity galaxies, i.e. $\alpha \to 1.6$, due to increasingly lower efficiency for the production of gamma-ray emission. We further find that the measured data of the gamma-ray luminosity is compatible with such a steepening. The steepening in the slope suggests that cosmic-ray escape is very important in low-SFR galaxies.

arXiv comment9 pages, 4 figures, Accepted by ApJ

References in corpus (30)

• The Global Schmidt Law in Star Forming Galaxies
• Mass and environment as drivers of galaxy evolution in SDSS and zCOSMOS and the origin of the Schechter function
• The size distribution of galaxies in the Sloan Digital Sky Survey
• The Star Formation Rate and Dense Molecular Gas in Galaxies
• The Galactic disk mass function: reconciliation of the HST and nearby determinations
• Estimating Star Formation Rates from Infrared and Radio Luminosities: The Origin of the Radio-Infrared Correlation
• Mapping Large-Scale Gaseous Outflows in Ultraluminous Galaxies with Keck II ESI Spectra: Variations in Outflow Velocity with Galactic Mass
• Ubiquitous outflows in DEEP2 spectra of star-forming galaxies at z=1.4
• GeV Observations of Star-forming Galaxies with \textit{Fermi} LAT
• A connection between star formation activity and cosmic rays in the starburst galaxy M 82
• Detection of Gamma Rays From a Starburst Galaxy
• Detection of Gamma-Ray Emission from the Starburst Galaxies M82 and NGC 253 with the Large Area Telescope on Fermi
• On The GeV & TeV Detections of the Starburst Galaxies M82 & NGC 253
• The Nature of Starburst Activity in M82
• Milky Way vs Andromeda: a tale of two disks
• Fermi Large Area Telescope observations of Local Group galaxies: Detection of M31 and search for M33
• Theoretical modelling of the diffuse emission of gamma-rays from extreme regions of star formation: The case of Arp 220
• The shapes of galaxies in the Sloan Digital Sky Survey
• High energy gamma-ray emission from the starburst nucleus of NGC 253
• An ATCA 20cm Radio Continuum Study of the Large Magellanic Cloud
• First detection of GeV emission from an ultraluminous infrared galaxy: Arp 220 as seen with the Fermi Large Area Telescope
• Simulating Gamma-ray Emission in Star-forming Galaxies
• High Energy Emission from the Starburst Galaxy NGC253
• Discovery of GeV emission from the direction of the luminous infrared galaxy NGC 2146
• Are Starburst Galaxies Proton Calorimeters?
• The Sub-parsec Scale Radio Properties of Southern Starburst Galaxies. I. Supernova Remnants, the Supernova Rate, and the Ionised Medium in the NGC 253 Starburst
• Constraining Gamma-Ray Emission from Luminous Infrared Galaxies with Fermi-LAT; Tentative Detection of Arp 220
• Cosmic Rays, Gamma-Rays, and Neutrinos in the Starburst Nuclei of Arp 220
• EGRET upper limits and stacking searches of gamma-ray observations of luminous and ultra-luminous infrared galaxies
• Comparative study of gamma-ray emission from molecular clouds and star-forming galaxies

Cited by in corpus (6)

• The effects of cosmic rays on the formation of Milky Way-mass galaxies in a cosmological context
• The gamma-ray / infrared luminosity correlation of star-forming galaxies
• Exploring the physics behind the non-thermal emission from star-forming galaxies detected in gamma rays
• Evidence of AGN activity in the gamma-ray emission from two starburst galaxies
• Constraining Cosmic-ray Transport with Observations of the Circumgalactic Medium
• A serendipitous discovery of GeV gamma-ray emission from supernova 2004dj in a survey of nearby star-forming galaxies with Fermi-LAT