A Possible Evolutionary Connection between Agn and Starburst in Liners

Our analysis on the two magnitude-limited samples of LINERs suggests a correlation between LFIR/LB or f(25μm)/f(60μm), and Hubble-type index at >99.99% significance level. As LFIR/LB and f(25μm)/f(60μm) are considered as the indicators of star-formation activity and AGN activity, respectively, our result suggests that LINERs with higher AGN activity may have a lower star-formation contribution. The ones with highest AGN activity and lowest star-formation contributions are ellipticals. All well-studied LINER 1s belong to this group. On the other hand, LINERs with higher star-formation activity present lower AGN contributions. We find all well-studied LINER 2s in this parameter space. Most of LINERs having inner ring structures belong to this group. Statistics with other indicators of starformation or AGN activity (nulear mass-to-light ratio at H band, and the ratio of X-ray-to-UV power) provide further evidence for such a trend. We have seen that along with the evolution of galaxies from late-type spirals to early-type ones, and up to ellipticals, the intensity of AGN activity increases with decreasing star-formation contributions, The above analyses may suggest a possible connection between the host galaxies and nuclear activities, and it might also indicate a possible evolutionary connection between AGN and starburst in LINERs. Subject headings: galaxies: active — galaxies: evolution — galaxies: nuclei — galaxies: starburst — galaxies: Seyfert