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
Presented are new images of supernova remnants G114.3±0.3, G116.5＋1.1 and G116.9＋0.2 （CTB 1） at 408 MHz from the Canadian Galactic Plane Survey （CGPS）. We also use the 1420 MHz images from the CGPS in a stu...Presented are new images of supernova remnants G114.3±0.3, G116.5＋1.1 and G116.9＋0.2 （CTB 1） at 408 MHz from the Canadian Galactic Plane Survey （CGPS）. We also use the 1420 MHz images from the CGPS in a study of their 408-1420 MHz spectral indices. The flux densities at 408 MHz and 1420 MHz, corrected for flux densities from compact sources within the SNRs, are 12±6 Jy and 9.8±0.8 Jy for G114.3＋0.3, 15.0±1.5 Jy and 10.6±0.6 Jy for G116.5＋1.1, 15.0＋1.5 Jy and 8.1±0.4 Jy for Gl16.9＋0.2. The integrated flux density-based spectral indices （Sv∝v^-α） are α=0.16±0.41, 0.28±0.09 and 0.49±0.09 for G114.3＋0.3, G116.5＋1.1 and G116.9＋0.2, respectively. Their T-T plot-based spectral indices are 0.68±0.48, 0.28±0.15, and 0.48±0.04, in agreement with the integrated flux density-based spectral indices. New flux densities are derived at 2695 MHz which are significantly larger than previous values. The new 408, 1420 and 2695 MHz flux densities and published values at other frequencies, where images are not available, are fitted after correcting for contributions from compact sources, to derive their multi-frequency spectral indices.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.
文摘Presented are new images of supernova remnants G114.3±0.3, G116.5＋1.1 and G116.9＋0.2 （CTB 1） at 408 MHz from the Canadian Galactic Plane Survey （CGPS）. We also use the 1420 MHz images from the CGPS in a study of their 408-1420 MHz spectral indices. The flux densities at 408 MHz and 1420 MHz, corrected for flux densities from compact sources within the SNRs, are 12±6 Jy and 9.8±0.8 Jy for G114.3＋0.3, 15.0±1.5 Jy and 10.6±0.6 Jy for G116.5＋1.1, 15.0＋1.5 Jy and 8.1±0.4 Jy for Gl16.9＋0.2. The integrated flux density-based spectral indices （Sv∝v^-α） are α=0.16±0.41, 0.28±0.09 and 0.49±0.09 for G114.3＋0.3, G116.5＋1.1 and G116.9＋0.2, respectively. Their T-T plot-based spectral indices are 0.68±0.48, 0.28±0.15, and 0.48±0.04, in agreement with the integrated flux density-based spectral indices. New flux densities are derived at 2695 MHz which are significantly larger than previous values. The new 408, 1420 and 2695 MHz flux densities and published values at other frequencies, where images are not available, are fitted after correcting for contributions from compact sources, to derive their multi-frequency spectral indices.
