河外射电源的核谱指数和延展谱指数(英文)

The Core and Extended Spectral Indices of Extragalatic Radio Sources

我们采用 6cm和 2 0cm核流量密度和总流量密度的观测资料 ,分别计算出星系和类星体的核谱指数和延展谱指数 .此外 ,我们得到 :(1 )核谱指数和核主导系数相关 ;(2 )核主导系数同红移线性相关。

The relativistic beaming model has been successfully used to explain the observational properties of active galactic nuclei (AGNs). In this model the emissions are composed of two components, namely, the boosted and the isotropic extended ones. Most blazars show flat radio spectral indices, but spectral indices for core and extended components are not very clear. In this paper, we have used the observed core and total flux densities at 6 cm and 20 cm to determine the core and extended spectral indices for galaxies and QSOs, respectively. On average, the core and extended spectral indices are α core =1.03±0.11, α ext =0.90±0.13 for galaxies; α core =0.29±0.09, α ext =0.68±0.07 for QSOs. We also found: 1) the core spectral index and core dominance parameter (R) show a relation: ν α c ∝(1+1/R ν) ; 2) R is approximately linearly correlated with redshift(z).