The Power Spectrum and Structure Function of the Gamma-Ray Emission from the Large Magellanic Cloud

The Fermi-LAT observational data of the diffuse γ ray emission from Large Magellanic Cloud (LMC) were examined to test for existence underlying long-range correlations. A statistical applied indicated that probability are random is extremely small. Thus we proceeded and have used counts-number compute 2D spatial autocorrelation, power spectrum, structure function. most important result present study a clear indication large-scale This evident in all functions mentioned above. spectrum has logarithmic slope −3 on large scales −4 small scales. function slopes equaling 1 2 scales, respectively. consistent. plausible interpretation these results supersonic compressible turbulence with 3D extending over comparable size LMC. Both exhibit steeper smaller interpreted as an turbulent region effective depth about 1.5 kpc.