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GMOS-South Probes Gas and Stellar Dynamics in Post-Merger Galaxy
23 Febrero 2005: About 500 million years ago a spheroidal galaxy captured a small gas-rich galaxy in a merger that led to a burst of star formation. Using the integral field unit (IFU) on GMOS-South, Mark Swinbank (University of Durham, UK), led an international research team to explore this merging system that is still in the process of digesting the gas and stellar components of the two original galaxies. The galaxy SDSS J101345.39+011613.06, known simply as “E+A” (geminiann05002a), has a redshift of 0.1055, corresponding to a distance of roughly 490 Mpc (or 1.6 billion light-years). This hybrid galaxy has a disturbed morphology and shows signatures of both old low-mass stars (spectral type K) and massive but short-lived stars (spectral type A) distributed throughout. However, the youngest and most massive ones—the OB-type stars—are missing, which indicates that the last star-forming event in E+A took place a few hundred million years ago. Recent spectroscopy conducted …