Radio-infrared correlation for local dusty galaxies and dusty AGNs from the AKARI All-Sky Survey

摘要

We use the new release of the AKARI Far-Infrared All-Sky Survey (FIS) matched with the NVSS radio database to investigate the local (z < 0.25) far-infrared-radio correlation (FIRC) of different types of extragalactic sources. To obtain the redshift information for the AKARI FIS sources we cross-match the catalogue with the SDSS DR8. This also allows us to use emission line properties to divide sources into four categories: (i) star-forming galaxies (SFGs), (ii) composite galaxies (displaying both star formation and active nucleus components), (iii) Seyfert galaxies, and (iv) low-ionization nuclear emission-line region (LINER) galaxies. We find that the Seyfert galaxies have the lowest far-infrared/radio flux ratios and display excess radio emission when compared to the SFGs. We conclude that the FIRC can be used to separate SFGs and AGNs only for the most radio-loud objects.