Statistical Research On High-energy Radiation Of Blazars

Active galactic nuclei?AGNs?have strong activity,and balzars are a subclass of AGNs.Because the direction of the jet is very close to the line of the observer's sight,thus blazars has many extreme observational properties,including strong high-energetic emissions.Although there are many researchers who have systematically studied the blazars,the origins of the high energy emissions of blazars still have many disputes,especially Very High Energy?VHE/TeV?emissions.Thus,it is still very important to study the high energy emissions of blazars.In this work,the first chapter introduces the research background of the blazars and its high energetic emissions.Chapters 2 to 5 describe our research work,we study the high energetic observational properties of blazars,and statistical analysis is performed with multi-wavelength observational data.We find that:?1?TeV BL Lacertae objects?BL Lacs?show similar observational properties to high synchrotron peaked BL Lacs;?2?The correlation between intrinsic?-ray emissions and redshift is follow the theoretical relation;?3?For TeV blazars,the correlation between the peak frequency and the curvature of synchrotron bump is clearly different from that of the inverse-Compton bump,which indicates that there are different emission mechanisms between them.?4?96 TeV blazars candidates are obtained by using logistic regression analysis,and so on.The specific descriptions are as follows;In Chapter 2,we collect 662 BL Lacs,including 47 TeV BL Lacs.Their multi-wavelength data are compiled,then we compare TeV BL Lacs with other subclasses of BL Lacs.We find that TeV BL Lacs are different from low synchrotron peaked and intermediate synchrotron peaked BL Lacs in multi-wavelength observational properties,but TeV BL Lacs show similar properties to high synchrotron peaked BL Lacs.In Chapter 3,we collect 91 Fermi blazars with radio Doppler factors,calculate the intrinsic flux density (?f_?ⁱⁿ) and intrinsic peak frequency (??_pⁱⁿ).We find that the correlation between (?f_?ⁱⁿ) and redshift is follow the theoretical relation:?f=-2.0?z+const.When we consider the subclasses of blazars,we find that the stationary jets are perhaps dominant in low synchrotron peaked blazars.We also find that there is strong correlation between (?f_?ⁱⁿ) and (??_pⁱⁿ),which suggests that synchrotron emissions are highly correlated with?-ray emissions.In Chapter 4,we study the spectral energy distributions?SEDs?of 69 TeV blazars.By using the second degree polynomial function to fit the SEDs,the structure parameters of the synchrotron bumps for 68 TeV blazars and those of the inverse-Compton bumps for 56 TeV blazars are obtained.We find that:1.There is a clear positive correlation between the synchrotron peak frequency and the inverse-Compton peak frequency,and that between the synchrotron peak luminosity and the inverse-Compton peak luminosity.2.The correlation between the peak frequency and the curvature of synchrotron bump is clearly different from that of the inverse-Compton bump,which indicates that there are different emission mechanisms between them.3.There is an anti-correlation between inverse-Compton peak frequency and?-ray photon index,which is consistent with previous work of Abdo et al.?2010?.4.An?L-shape?relation is found between synchrotron peak frequency and X-ray photon index for both TeV blazars and Fermi blazars.5.In the X-ray photon index versus?-ray photon index diagram,there is also an?L-shape?,the anti-correlation is consistent with the available results in the literature,and we also find a positive correlation between them.In Chapter 5,we study the multi-wavelength observational data of 1180 Fermi blazars,and find that different wave bands data show different behaviors of correlation between flux density and synchrotron peak frequency.There are significant anti-correlations between Radio/?-ray flux density and synchrotron peak frequency,while X-ray/optical flux density and synchrotron peak frequency show clear positive correlations.Because the flux density of TeV band is very low and hard to be detected,so we use a logistic regression model to predict the TeV blazars with multi-wavelength observational data,then we obtain a prediction equation.For the Fermi blazars,the accuracy of the prediction equation is 89.22%.Only 4 TeV sources are incorrectly classified as non-TeV sources by the prediction equation,and 93.1%TeV blazars are correctly classified.From this equation,we obtain a sample of 96 TeV blazars candidates.