| Blazars are a special and important sub class of Active Galactic Nuclei.Due to vary small pitch angle between jets and line of sight.It is accept that synchrotron peaked frequency is as-sociated with radio/optical/X-ray spectral index,and radio/optical/X-ray spectral index is used to estimate synchrotron peaked frequency.This correlation works well for low synchrotron peaked blazars,but large error for high synchrotron peaked blazars.We collected multi-band observa-tion of 68 Fermi blazars for a further study.We calculated their spectral energy distribution,and the correlation between synchrotron peak and board band spectral index is discussed.We intro-duce AGNs and study of spectral energy distributions of synchrotron peaks in Chapter 1.Chap-ter 2 describe fitting procedure of spectral energy distributions.In chapter 3,we discuss our re-search about spectral index.The mains result are as follow:?1?Spectral energy distribution of68 Fermi blazars is calculated,and the correlation between synchrotron peaked frequency and effective spectral index is obtained.For high synchrotron peaked blazars,it is impossible to estimate synchrotron peaked frequency accurately via spectral index.?2?From the linear cor-relation between the synchrotron peaked frequency?lg?p?and curvature?2k?,we find that the result?1/k=?2.57±0.21?Ślg?p-29.26±3.31?support energy-dependent acceleration probabil-ity model for all BL Lac,while the result?1/k=?3.38±0.34?Ślg?p-42.84±5.65?for BL Lac with lg?p>15.3 is consistent with the fluctuation of fractional acceleration gain model.?3?For the sources with nearlylg?p,a significant correlation between effective spectral index?roand cur-vature is detected,while effective spectral index?oxis not associated with curvature.According to effective spectral?ro,a correlation between synchrotron peaked frequency and curvature can be found. |
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