Supernova remnants(SNRs)interacting with molecular clouds(MCs)are recognized as the sources of γ-rays and cosmic rays in the Galaxy.Based on the SNR-MC system,this study establishes a particle cumulative diffusion mo...Supernova remnants(SNRs)interacting with molecular clouds(MCs)are recognized as the sources of γ-rays and cosmic rays in the Galaxy.Based on the SNR-MC system,this study establishes a particle cumulative diffusion model to investigate the mechanism by which high-energy protons escaping from SNRs interact with dense MCs through proton–proton interactions to produce high-energyγ-rays.Using the W51 complex,a typical star-forming region,as a research sample,we analyze the production and propagation characteristics of γ-rays.By employing the Exponential Cutoff Power-Law model and the Markov Chain Monte Carlo method,we fit theγ-ray observational data of W51C,successfully constraining the key physical parameters.Additionally,we systematically search for 1LHAASO sources spatially coincident with SNR-MC systems to explore the potential origins of ultra-high-energy(UHE) γ-ray sources.The results indicate that the radiation characteristics of the UHE γ-ray sources are highly consistent with the SNR-MC systems,further supporting their candidacy as PeVatrons in the Galaxy.展开更多
In this paper,we analyze the spectral energy distributions of 17 powerful(with a spin-down luminosity greater than10~(35)erg s~(-1))young(with an age less than 15,000 yr)pulsar wind nebulae(PWNe)using a simple timein-...In this paper,we analyze the spectral energy distributions of 17 powerful(with a spin-down luminosity greater than10~(35)erg s~(-1))young(with an age less than 15,000 yr)pulsar wind nebulae(PWNe)using a simple timein-dependent one-zone emission model.Our aim is to investigate correlations between model parameters and the ages of the corresponding PWNe,thereby revealing the evolution of high-energy electron distributions within PWNe.Our findings are as follows:(1)The electron distributions in PWNe can be characterized by a double power-law with a super-exponential cutoff.(2)As PWNe evolve,the high-energy end of the electron distribution spectrum becomes harder with the index decreasing from approximately 3.5 to 2.5,while the low-energy end spectrum index remains constant near 1.5.(3)There is no apparent correlation between the break energy or cutoff energy and the age of PWNe.(4)The average magnetic field within PWNe decreases with age,leading to a positive correlation between the energy loss timescale of electrons at the break energy or the high-energy cutoff and the age of the PWN.(5)The total electron energy within PWNe remains constant near 2×10~(48)erg,while the total magnetic energy decreases with age.展开更多
基金supported by NSFC grant No.12393852the Yunnan Fundamental Research Project(grant No.202501AS070068).
文摘Supernova remnants(SNRs)interacting with molecular clouds(MCs)are recognized as the sources of γ-rays and cosmic rays in the Galaxy.Based on the SNR-MC system,this study establishes a particle cumulative diffusion model to investigate the mechanism by which high-energy protons escaping from SNRs interact with dense MCs through proton–proton interactions to produce high-energyγ-rays.Using the W51 complex,a typical star-forming region,as a research sample,we analyze the production and propagation characteristics of γ-rays.By employing the Exponential Cutoff Power-Law model and the Markov Chain Monte Carlo method,we fit theγ-ray observational data of W51C,successfully constraining the key physical parameters.Additionally,we systematically search for 1LHAASO sources spatially coincident with SNR-MC systems to explore the potential origins of ultra-high-energy(UHE) γ-ray sources.The results indicate that the radiation characteristics of the UHE γ-ray sources are highly consistent with the SNR-MC systems,further supporting their candidacy as PeVatrons in the Galaxy.
基金supported by the National Natural Science Foundation of China(Nos.12220101003,12273114,U1931204,12103040,12147208 and U2031111)the Project for Young Scientists in Basic Research of Chinese Academy of Sciences(No.YSBR-061)the Program for Innovative Talents and Entrepreneur in Jiangsu。
文摘In this paper,we analyze the spectral energy distributions of 17 powerful(with a spin-down luminosity greater than10~(35)erg s~(-1))young(with an age less than 15,000 yr)pulsar wind nebulae(PWNe)using a simple timein-dependent one-zone emission model.Our aim is to investigate correlations between model parameters and the ages of the corresponding PWNe,thereby revealing the evolution of high-energy electron distributions within PWNe.Our findings are as follows:(1)The electron distributions in PWNe can be characterized by a double power-law with a super-exponential cutoff.(2)As PWNe evolve,the high-energy end of the electron distribution spectrum becomes harder with the index decreasing from approximately 3.5 to 2.5,while the low-energy end spectrum index remains constant near 1.5.(3)There is no apparent correlation between the break energy or cutoff energy and the age of PWNe.(4)The average magnetic field within PWNe decreases with age,leading to a positive correlation between the energy loss timescale of electrons at the break energy or the high-energy cutoff and the age of the PWN.(5)The total electron energy within PWNe remains constant near 2×10~(48)erg,while the total magnetic energy decreases with age.
