Red galaxies with pseudo-bulges in the SDSS: closer to disk galaxies or to classical bulges?
| Autor: | Ribeiro, B., Lobo, C., Antón, S., Gomes, J. M., Papaderos, P. |
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| Rok vydání: | 2015 |
| Předmět: | |
| Zdroj: | 2016, MNRAS, 456, 3899 |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1093/mnras/stv2872 |
| Popis: | Pseudo-bulges are expected to markedly differ from classical, quasi-monolithically forming bulges in their star formation history (SFH) and chemical abundance patterns. To test this simple expectation, we carry out a comparative structural and spectral synthesis analysis of 106 red, massive galaxies issued from the SDSS, subdivided into bulgeless, pseudo-bulge and classical bulge galaxies according to their photometric characteristics, and further obeying a specific selection to minimize uncertainties in the analysis and ensure an unbiased derivation and comparison of SFHs. Our 2D photometry analysis suggests that disks underlying pseudo-bulges typically have larger exponential scale lengths than bulgeless galaxies, despite similar integral disk luminosities. Spectral synthesis models of the stellar emission within the 3" SDSS fiber aperture reveal a clear segregation of bulgeless and pseudo-bulge galaxies from classical bulges on the luminosity-weighted planes of age-metallicity and mass-metallicity, though a large dispersion is observed within the two former classes. The secular growth of pseudo-bulges is also reflected upon their cumulative stellar mass as a function of time, which is shallower than that for classical bulges. Such results suggest that the centers of bulgeless and pseudo-bulge galaxies substantially differ from those of bulgy galaxies with respect to their SFH and chemical enrichment history, which likely points to different formation/assembly mechanisms. Comment: 18 pages, 12 figure, accepted for MNRAS |
| Databáze: | arXiv |
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