Does Low Surface Brightness Mean Low Density?
نویسندگان
چکیده
We compare the dynamical properties of two galaxies at identical positions on the Tully-Fisher relation, but with different surface brightnesses. We find that the low surface brightness galaxy UGC 128 has a higher mass-to-light ratio, and yet has lower mass densities than the high surface brightness galaxy NGC 2403. This is true for the gas surface density, the stellar surface density, and the total mass density. Subject headings: dark matter— galaxies: fundamental parameters — galaxies: individual (NGC 2403, UGC 128)— galaxies: kinematics and dynamics— galaxies: spiral — galaxies: structure
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