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Paper: Interactions and Star Formation in Galaxies
Volume: 390, Pathways Through an Eclectic Universe
Page: 188
Authors: Knapen, J.H.; James, P.A.
Abstract: We present results derived from Hα images of 327 local galaxies from the HaGS (Hα Galaxy Survey), where we have correlated the star formation rates with the interaction characteristics of the galaxies. We see a significant increase in the star formation rate in galaxies with close neighbors, an increase which has probably been triggered by galaxy–galaxy interactions. But when we analyze the equivalent width of the Hα emission, which is the Hα flux normalized by the continuum emission, or a measure of the current compared to the average past star formation rate, we find that galaxies with close companions show no significant enhancement at all. Our conclusion is that although close neighbors and interactions increase the star formation rate, they do this continuously. When we define a starburst as a star formation event with a star formation rate that is currently higher than it has been on average in the past, we must thus conclude that the presence of a close companion does not lead to starburst activity.
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