Abstract G349.7＋0.2 is an interacting supernova remnant （SNR） expanding in a dense medium. Recently, a very strong γ-ray source coincident with this SNR has been revealed by Fermi-LAT and H.E.S.S. ob- servations w...Abstract G349.7＋0.2 is an interacting supernova remnant （SNR） expanding in a dense medium. Recently, a very strong γ-ray source coincident with this SNR has been revealed by Fermi-LAT and H.E.S.S. ob- servations which shows a broken power-law-like spectrum. An escaping-diffusion model, including the power-law and g-function injection, is applied to this source which can naturally explain the spectral fea- ture in both the GeV and TeV regime. We use the Markov Chain Monte Carlo method to constrain the model parameters and find that the correction factor of slow diffusion around this SNR, X-0.01 for power-law injection and X - 0.1 for g-function injection, can fit the data best with reasonable molecular cloud mass. This slow diffusion is also consistent with previous results from both phenomenological models and theoretical predication.展开更多
Using the Shell-Model Monte Carlo method and the Random Phase Approximation theory, we carry out an estimation of neutrino energy loss （NEL） for 55Co and 56Ni by electron capture. We find that the NEL rates increase...Using the Shell-Model Monte Carlo method and the Random Phase Approximation theory, we carry out an estimation of neutrino energy loss （NEL） for 55Co and 56Ni by electron capture. We find that the NEL rates increase greatly at some typical stellar conditions, and can even exceed five orders of magnitude （e.g. T9 = 38.5, Ye = 0.42 for 56Ni）. On the other hand, the error factor C shows that the fit is fairly good for two results at higher density and lower temperature, and the max- imum error is - 1.2%. However, the maximum error is ,- 55.60% （e.g. T9 = 18.5, Ye = 0.45） at lower density and higher temperature.展开更多
Based on the shell-model Monte Carlo method and random phase approximation theory, the neutrino energy spectrum （NES） and the electron capture （EC） of ^56Fe, ^56Co, ^56Ni, ^56Mn, ^56Cr and ^56V are investigated in...Based on the shell-model Monte Carlo method and random phase approximation theory, the neutrino energy spectrum （NES） and the electron capture （EC） of ^56Fe, ^56Co, ^56Ni, ^56Mn, ^56Cr and ^56V are investigated in presupemova surroundings. The results show that the EC rates are affected greatly at different densities and temperatures. The rates increase greatly and even exceed six orders of magnitude at lower temperature. On the other hand, the NES is very sensitive to stellar temperature and electron energy. The higher the temperature and the lower the electron energy, the larger the influence on NES is. For example, the maxima of NES in the ground state are 9.02, 160, 80, 24.01, 0.44, 1.42 me c^2 for ^56Fe, ^56Co, ^56Ni, ^56Mn, ^56Cr and ^56V respectively at ρ7 = 10.7, Ye = 0.45 and T9 = 15. Furthermore, the influence on NES due to EC for different nuclei has some otherness because of different Qo-values. For example, the spectrum of ^56Co shows a double bump structure.展开更多
Following the theory of relativity, in the presence of an ultrastrong magnetic field （UMF） and utilizing a nuclear shell model, we carry out an estimation of the neutrino energy loss （NEL） rates of nuclides ^53-60...Following the theory of relativity, in the presence of an ultrastrong magnetic field （UMF） and utilizing a nuclear shell model, we carry out an estimation of the neutrino energy loss （NEL） rates of nuclides ^53-60Cr, which occur by electron capture in magnetars. The results show that the NEL rates greatly increase when a UMF is present, and can even exceed nine orders of magnitude at relatively lower density and temperature （e.g. ρ7 = 5.86, Ye = 0.47, T9 = 7.33） in the range from 1013 G to 1018 G. However, the increase in rates was no more than six orders of magnitude at relatively higher density and temperature （e.g.ρ7 = 4.86 × 10^8, Ye = 0.39, T9 = 14.35）.展开更多
We test the distance-duality （DD） relation by combining the angular diameter distance DA provided by two galaxy cluster samples compiled by De Filippis et al. （the elliptical β model） and Bonamente et al. （the s...We test the distance-duality （DD） relation by combining the angular diameter distance DA provided by two galaxy cluster samples compiled by De Filippis et al. （the elliptical β model） and Bonamente et al. （the spherical β model）, and the luminosity distance DL from Constitution and Union2 type Ia supernova （SNe Ia） datasets. To obtain DL associated with the observed DA at the same redshift, we smooth the noise of the SNe Ia in a model-independent way, obtain the evolutionary curve of DL and, finally, test the DD relation. We find that the elliptical β model, when compared with the SNe Ia from the Constitution compilation, is only consistent with the DD relation at the 3σ confidence level （CL）, while the spherical β model is incompatible with the DD relation at the 3σ CL. For the Union2 compilation, the De Filippis and Bonamente samples are marginally compatible with the validity of the DD relation at the 1σ and 2σ CLs, respectively.展开更多
The distribution of dense molecular gas around the supernova rem- nant G40.5-0.5 has been investigated by radio spectroscopic observations in the CO （J=1 - 0） transition. The molecular gas is found to extend over th...The distribution of dense molecular gas around the supernova rem- nant G40.5-0.5 has been investigated by radio spectroscopic observations in the CO （J=1 - 0） transition. The molecular gas is found to extend over the entire region of G40.5-0.5. A molecular shell, with a diameter of ～ 26′, coincides with the ionized gas as revealed by the cm-radio observations. This coincidence, along with the velocity discontinuity following the shell, provides direct evidence for interaction between the ionized gas and the dense molecular gas. No clear evidence for cosmic-ray accelera- tion can be identified from this SNR as previously suggested, due to positional uncertainty in relating the SNR shell defined by CO to the EGRET gamma-ray sources, GRO J1904＋06, from the gamma-ray observations.展开更多
基金the support of the National Natural Science Foundation of China(Grant No.11233001)973 Program(Grant 2015CB857100)+1 种基金he Educational Ministry of China(Grant 20120091110048)the program B for Outstanding PhD candidate of Nanjing University
文摘Abstract G349.7＋0.2 is an interacting supernova remnant （SNR） expanding in a dense medium. Recently, a very strong γ-ray source coincident with this SNR has been revealed by Fermi-LAT and H.E.S.S. ob- servations which shows a broken power-law-like spectrum. An escaping-diffusion model, including the power-law and g-function injection, is applied to this source which can naturally explain the spectral fea- ture in both the GeV and TeV regime. We use the Markov Chain Monte Carlo method to constrain the model parameters and find that the correction factor of slow diffusion around this SNR, X-0.01 for power-law injection and X - 0.1 for g-function injection, can fit the data best with reasonable molecular cloud mass. This slow diffusion is also consistent with previous results from both phenomenological models and theoretical predication.
基金supported by the Advanced Academy Special Foundation of Sanya under Grant No. 2011YD14
文摘Using the Shell-Model Monte Carlo method and the Random Phase Approximation theory, we carry out an estimation of neutrino energy loss （NEL） for 55Co and 56Ni by electron capture. We find that the NEL rates increase greatly at some typical stellar conditions, and can even exceed five orders of magnitude （e.g. T9 = 38.5, Ye = 0.42 for 56Ni）. On the other hand, the error factor C shows that the fit is fairly good for two results at higher density and lower temperature, and the max- imum error is - 1.2%. However, the maximum error is ,- 55.60% （e.g. T9 = 18.5, Ye = 0.45） at lower density and higher temperature.
基金supported by the Natural Science Foundation of Hainan province (Grant No.114012)
文摘Based on the shell-model Monte Carlo method and random phase approximation theory, the neutrino energy spectrum （NES） and the electron capture （EC） of ^56Fe, ^56Co, ^56Ni, ^56Mn, ^56Cr and ^56V are investigated in presupemova surroundings. The results show that the EC rates are affected greatly at different densities and temperatures. The rates increase greatly and even exceed six orders of magnitude at lower temperature. On the other hand, the NES is very sensitive to stellar temperature and electron energy. The higher the temperature and the lower the electron energy, the larger the influence on NES is. For example, the maxima of NES in the ground state are 9.02, 160, 80, 24.01, 0.44, 1.42 me c^2 for ^56Fe, ^56Co, ^56Ni, ^56Mn, ^56Cr and ^56V respectively at ρ7 = 10.7, Ye = 0.45 and T9 = 15. Furthermore, the influence on NES due to EC for different nuclei has some otherness because of different Qo-values. For example, the spectrum of ^56Co shows a double bump structure.
基金supported by the Advanced Academy Special Foundation of Sanya (Grant No. 2011YD14)
文摘Following the theory of relativity, in the presence of an ultrastrong magnetic field （UMF） and utilizing a nuclear shell model, we carry out an estimation of the neutrino energy loss （NEL） rates of nuclides ^53-60Cr, which occur by electron capture in magnetars. The results show that the NEL rates greatly increase when a UMF is present, and can even exceed nine orders of magnitude at relatively lower density and temperature （e.g. ρ7 = 5.86, Ye = 0.47, T9 = 7.33） in the range from 1013 G to 1018 G. However, the increase in rates was no more than six orders of magnitude at relatively higher density and temperature （e.g.ρ7 = 4.86 × 10^8, Ye = 0.39, T9 = 14.35）.
基金Supported by the National Natural Science Foundation of China(Grants Nos. 10935013 and 11075083)the Zhejiang Provincial Natural Science Foundation of China under Grant No. Z6100077+3 种基金the FANEDD under Grant No. 200922the National Basic Research Program of China (Grant No. 2010CB832803)the NCET under Grant No. 09-0144the PCSIRT under Grant No. IRT0964
文摘We test the distance-duality （DD） relation by combining the angular diameter distance DA provided by two galaxy cluster samples compiled by De Filippis et al. （the elliptical β model） and Bonamente et al. （the spherical β model）, and the luminosity distance DL from Constitution and Union2 type Ia supernova （SNe Ia） datasets. To obtain DL associated with the observed DA at the same redshift, we smooth the noise of the SNe Ia in a model-independent way, obtain the evolutionary curve of DL and, finally, test the DD relation. We find that the elliptical β model, when compared with the SNe Ia from the Constitution compilation, is only consistent with the DD relation at the 3σ confidence level （CL）, while the spherical β model is incompatible with the DD relation at the 3σ CL. For the Union2 compilation, the De Filippis and Bonamente samples are marginally compatible with the validity of the DD relation at the 1σ and 2σ CLs, respectively.
基金Supported by the National Natural Science Foundation of China.
文摘The distribution of dense molecular gas around the supernova rem- nant G40.5-0.5 has been investigated by radio spectroscopic observations in the CO （J=1 - 0） transition. The molecular gas is found to extend over the entire region of G40.5-0.5. A molecular shell, with a diameter of ～ 26′, coincides with the ionized gas as revealed by the cm-radio observations. This coincidence, along with the velocity discontinuity following the shell, provides direct evidence for interaction between the ionized gas and the dense molecular gas. No clear evidence for cosmic-ray accelera- tion can be identified from this SNR as previously suggested, due to positional uncertainty in relating the SNR shell defined by CO to the EGRET gamma-ray sources, GRO J1904＋06, from the gamma-ray observations.
