Séminaire/Seminar Galaxies |
| « Photometric scaling relations of bulges and disks » |
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Louis Quilley |
| I revisit the scaling relations between absolute magnitude, effective radii and surface brightness as a function of morphology, for the bulges and disks of the nearby Universe. I use SourceXtractor++ on the EFIGI catalog of 4458 nearby galaxies to decompose them as a disk and a bulge in the SDSS g, r, i bands. This allows me to retrieve the Kormendy (1977) and Binggeli (1984) relations for elliptical galaxies. I also obtain them for bulges of lenticular and spiral types until Sb, but show a departure from these relations for bulges of later types. I show that the bulge-to-total ratio is key in determining the position in the 3D space of size, luminosity and brightness, and discuss the implications on the nature of bulges, especially on the classical bulge/pseudo-bulge dichotomy. I also show similar relations for the disk components. Moreover, the size distributions of both bulges and disks, and their ratios, as a function of Hubble type, are consistent with the inverse Hubble sequence galaxy evolution picture proposed previously in Quilley & de Lapparent (2022). Finally, these parameter distributions and scaling laws are useful for building realistic mock catalogs. |
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jeudi 15 décembre 2022 - 11:30 Salle des séminaires Évry Schatzman Institut d'Astrophysique de Paris |
| Page web du séminaire / Seminar's webpage |