We examine whether galaxy environments directly affect triggering nuclear activity in Sloan Digital Sky Survey ( SDSS ) local spiral galaxies using a volume-limited sample with the r -band absolute magnitude M _ { r } < -19.0 and 0.02 < z < 0.055 selected from the SDSS Data Release 7 .
To avoid incompleteness of the central velocity dispersion \sigma of the volume-limited sample and to fix the black hole mass affecting AGN activity , we limit the sample to a narrow \sigma range of 130 ~ { } { km~ { } s ^ { -1 } } < \sigma < 200 ~ { } { km~ { } s ^ { -1 } } .
We define a variety of environments as a combination of neighbour interactions and local density on a galaxy .
After the central star formation rate ( which is closely related to AGN activity level ) is additionally restricted , the direct impact of the environment is unveiled .
In the outskirts of rich clusters , red spiral galaxies show a significant excess of the AGN fraction despite the lack of central gas .
We argue that they have been pre-processed before entering the rich clusters , and due to mergers or strong encounters in the in-fall region , their remaining gases efficiently lose angular momentum .
We investigate an environment in which many star-forming galaxies coexist with a few starburst-AGN composite hosts having the highest [ OIII ] luminosity .
We claim that they are a gas-rich merger product in groups or are group galaxies in-falling into clusters , indicating that many AGN signatures may be obscured following the merger events .