Metallicity and nuclear star formation in nearby galaxy pairs: evidence for tidally induced gas flows

摘要: We derive the first luminosity-metallicity relation for a large objectively selected sample of local galaxy pairs and we compare LZ with Nearby Field Galaxy Survey (NFGS). pair members small projected separations (s < 20 kpc/h) have systematically lower metallicities (� 0.2 dex on average) than field galaxies, or more widely separated at same luminosity. There is strong correlation between metallicity central burst strength in pairs. All five galaxies bursts close companions comparable galaxies. Our results provide observational evidence merger scenario where interactions cause gas flows towards regions, carrying less enriched from outskirts into regions. The dilutes pre-existing nuclear to produce would be obtained prior interaction. These trigger star formation, causing strengths, possibly aiding formation blue bulges. show that timescale dilution required by this are consistent predictions hydrodynamic models. Subject headings: galaxies:starburst–galaxies:abundances–galaxies:fundamental parameters– galaxies:interactions