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Keywords

galaxies: elliptical and lenticular
cD
stars: formation
stars: horizontal-branch

How to Cite

Possible Sources of UV Radiation in Elliptical Galaxies. (2009). Revista Mexicana De Astrofísica Y Astronomía Serie De Conferencias, 35(1), 158-159. https://astronomia.unam.mx/journals/rmxac/article/view/2009rmxac..35..158h
hola

Abstract

We have compiled a sample of 519 nearby (z < 0.13) elliptical galaxies, selected by matching the Galaxy Evolution Explorer (GALEX) Medium Imaging Survey (MIS) with the Sloan Digital Sky Survey (SDSS) Fourth Data Release (DR4). Our galaxies are bright, with r < 16.8 and have FUV (far ultraviolet) an NUV (near ultraviolet) emission. We build a UV Color Magnitude Relation (CMR) using GALEX and SDSS photometric bands, and analyze the evolution of this CMR for these galaxies using stellar population synthesis models. We find that these galaxies may have suffered a small amount of recent residual star formation (1-2% of the galaxy mass). Extreme Horizontal Branch (EHB) stars can explain galaxies with 4 < NUV-r < 5.4.