| Radio-luminous galaxies(RLGs) is a sub-class of active galaxies.The radio emissions from the galaxies are thought to originate from AGN and star formation. These RLGs are divided into Radio-loud active nuclei(RL AGNs) and star-forming galaxies(SFGs). We select the nearby RLGs to study the infrared colour properties of them. This paper includes three parts.In the first part, the author mainly introduce the formation of galaxies and the observation feature, categories, unification models and radio feature of active galaxies nuclei while describing the form procedure of stars. Also the research background for active galaxies of infrared radiation is stated.The second part is about the infrared survey and the infrared satellite.The third part is the research objects of this paper. By analyzing the 2712 infrared samples of RL AGNs obtained from 2MASS PSC, WISE PSC and AKARI-FIS PSC, there yields a statistical sample redshift distribution. The RL AGNs' redshift is mainly distributed between 0.05 and 0.5 and SFGs' is between 0.01 and 0.15. The two-colour diagram analysis of sample J(1.25 ?m), H(1.65 ?m)and Ks(2.17 ?m)shows that the RL AGNs meets the Kouzuma and Yamaoka's near-infrared AGNs selection rules are mainly distributed around the PL line, which means their near-infrared radiation mainly comes from the non-thermal emissions in the center of RL AGNs which some of it comes from the host galaxies. As to the SFGs that meets the selection rules, they are mainly distributed around BB line. This means their near-infrared radiation mainly come from the non-thermal emissions and the near-infrared radiation for those which are around the PL line mainly come from the non-thermal emissions of the nuclei. The colour distribution of K-S test for the J-Hs and sH-K of RL AGNs and SFGs shows that the sH-K colour distribution for both RL AGNs and SFGs are nearly the same while the J-H distribution is different. This means that the J wave frequency radiation is systematically different for RL AGNs and SFGs.The two-colour diagram analysis of sample W1(3.4 ?m),W2(4.6 ?m),W3(12 ?m)and W4(22 ?m)yields several meaningful results. In the([3.4]-[4.6])-([4.6]-[12]) two-colour diagram RL AGNs and SFGs are easily distinguished as RL AGNs are doble-core distribution while SFGs are single core distribution. Due to the serious influence of SFGs dust on the emissions, SFGs obtains a redder [4.6]-[12] colour feature than RL AGNs. Furthermore, 95% of [4.6]-[12] for RL AGNs is less than 3.0 and 94% of [4.6]-[12] for RL AGNs is larger than 3.0. This provides a simple rule to distinguish RL AGNs and SFGs from mid-infrared color. At the same time, the mid-infrared features for LERGs and HERGs RL AGNs are analyzed. It shows that they are differently distributed in [3.4]-[4.6],[4.6]-[12] and [12]-[22] colour diagrams which means that they have different mid-infrared features in essence.In the end, the author analyzes the spectral index for W3(12 ?m),W4(22 ?m), 90?m and 140?m and finds that there are many SFGs whose spectral ?(90,140) is less than-1.4 are distributed around the PL line between ?(90,140) and ?(22, 90). This means that ?(90,140)(27)-1.4 could be a selection rule for non-thermal emission nearby active galaxies in far infrared wave range. |
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