摘要
In this work,we reanalyzed 11 years of spectral data from the Fermi Large Area Telescope(Fermi-LAT)of currently observed starburst galaxies(SBGs)and star-forming galaxies(SFGs).We used a one-zone model provided by NAIMA and the hadronic origin to explain the GeV observation data of the SBGs and SFGs.We found that a protonic distribution of a power-law form with an exponential cutoff can explain the spectra of most SBGs and SFGs.However,it cannot explain the spectral hardening components of NGC 1068 and NGC 4945 in the GeV energy band.Therefore,we considered the two-zone model to well explain these phenomena.We summarized the features of two model parameters,including the spectral index,cutoff energy,and proton energy budget.Similar to the evolution of supernova remnants(SNRs)in the Milky Way,we estimated the protonic acceleration limitation inside the SBGs to be the order of 10^(2) TeV using the one-zone model;this is close to those of SNRs in the Milky Way.
基金
support for this work from the National Key R&D Program of China(Grant No.2018YFA0404204)
the National Natural Science Foundation of China(Grant Nos.U1931113,U1738211 and U193110119)
the Foundations of Yunnan Province(2018IC059 and 2018FY001(-003))
the Scientific Research Fund of Yunnan Education Department(2020Y0039)。
