ARE (pseudo)bulges in isolated galaxies actually primordial relics?
We present structural parameters and (g - i) bulge/disk colors for a large sample (189) of isolated AMIGA galaxies. The structural parameters of bulges were derived from the two-dimensional bulge/disk/bar decomposition of Sloan Digital Sky Survey i-band images using GALFIT. Galaxies were separated b...
| Autores: | , , , , , , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión aceptada para publicación |
| Fecha de publicación: | 2014 |
| País: | España |
| Institución: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/400684 |
| Acceso en línea: | http://hdl.handle.net/10261/400684 |
| Access Level: | acceso abierto |
| Palabra clave: | Galaxies: fundamental parameters Galaxies: general Galaxies: interactions |
| Sumario: | We present structural parameters and (g - i) bulge/disk colors for a large sample (189) of isolated AMIGA galaxies. The structural parameters of bulges were derived from the two-dimensional bulge/disk/bar decomposition of Sloan Digital Sky Survey i-band images using GALFIT. Galaxies were separated between classical bulges (nb > 2.5) and pseudobulges (nb < 2.5), resulting in a dominant pseudobulge population (94%) with only 12 classical bulges. In the langμ e rang-R e plane, pseudobulges are distributed below the elliptical relation (smaller R e and fainter μ e ), with the closest region to the Kormendy relation populated by those pseudobulges with larger values of B/T. We derived (g - i) bulge colors using aperture photometry and find that pseudobulges show median colors (g - i) b ~ 1.06, while their associated disks are much bluer, (g - i) d ~ 0.77. Moreover, 64% (113/177) of pseudobulges follow the red sequence of early-type galaxies. Bluer pseudobulges tend to be located in galaxies with the highest likelihood of tidal perturbation. The red bulge colors and low B/T values for AMIGA isolated galaxies are consistent with an early formation epoch and not much subsequent growth. Properties of bulges in isolated galaxies contrast with a picture where pseudobulges grow continuously via star formation. They also suggest that environment could be playing a role in rejuvenating the pseudobulges. © 2014. The American Astronomical Society |
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