The Core and Extended Spectral Indices of Extragalatic Radio Sources

Zhang Jiang-shui; Lin Rui-guang; Fan Jun-hui

Publications of the Yunnan Observatory > 2003 > 0(S1): 98-102.

Zhang Jiang-shui, Lin Rui-guang, Fan Jun-hui. The Core and Extended Spectral Indices of Extragalatic Radio Sources[J]. Publications of the Yunnan Observatory, 2003, (S1): 98-102.

Citation:

Zhang Jiang-shui, Lin Rui-guang, Fan Jun-hui. The Core and Extended Spectral Indices of Extragalatic Radio Sources[J]. Publications of the Yunnan Observatory, 2003, (S1): 98-102.

Citation:

Zhang Jiang-shui, Lin Rui-guang, Fan Jun-hui. The Core and Extended Spectral Indices of Extragalatic Radio Sources[J]. Publications of the Yunnan Observatory, 2003, (S1): 98-102.

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The Core and Extended Spectral Indices of Extragalatic Radio Sources

Center for Astrophysics, Guangzhou University, Guangzhou 510400, China.

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Published Date: October 30, 2003

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Abstract

Abstract

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_c^α ∝(1+1/ R_ν);2)R is approximately linearly correlated with redshift(z).
- AGN,
- blazars,
- radio emission,
- spectral indexes

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