Emission Line Galaxies and Active Galactic Nuclei in WINGS clusters

摘要: We present the analysis of emission line galaxies members 46 low redshift (0.04 < z 0.07) clusters observed by WINGS (WIde-field Nearby Galaxy cluster Survey, Fasano et al. 2006). Emission were identified following criteria that are meant to minimize biases against non-star forming and classified employing diagnostic diagrams. have examined properties frequencies star galaxies, transition objects active galactic nuclei (AGNs: LINERs Seyferts), unclassified with lines, quiescent no detectable emission. A deficit in environment is indicated both a lower frequency respect control samples, systematically Balmer equivalent width luminosity (up one order magnitude samples for objects) implies amount ionised gas per unit mass formation rate if source as Hii region. sizable population low-luminosity (approx. 10 - 20% all galaxies) detected among galaxies. With sources they factor approx. 1.5 more frequent than (or at least as) samples. Transition most affected terms appear predominantly consistent "retired" Shock heating can be possible excitation mechanism able account ratios. Specific environment, we suggest interaction between atomic molecular intracluster medium physical cause line-emitting shocks.