On the scaling relations of bulges and early-type galaxies

From WebRef.org
Jump to navigationJump to search Summer Sale Buy 4 Get 40% Off

Bogdan A. Pastrav

The study of bulge morphology and evolutionary history, together with the associated scaling relations, is essential in studies of galaxy formation and evolution. Following from our previous work (Pastrav 2020), we present a detailed structural analysis of a representative sample of nearby spiral and early-type galaxies taken from the KINGFISH/SINGS survey. The photometric parameters of bulges are obtained from bulge-disk decompositions using GALFIT data analysis algorithm. The method and the corrections previously obtained in Pastrav et al. (2013a,b) are used to derive intrinsic photometric and structural bulge parameters, corrected for projection and dust effects. We show the main bulge scaling relations and the black-hole relations, both the observed and the intrinsic ones, in the optical regime. We find dust and inclination effects to produce more important changes in the slope and zero-point of the Kormendy relation for spiral galaxies than those for ETGs, with bulges of spiral galaxies residing on a steeper slope relation that the early-type galaxies. We observe that the Kormendy relation in combination with a threshold in bulge Sérsic index (nb) does not clearly produce an accurate morphological separation of bulges, while nb-bulge-to-total flux ratio (B/T) and B/T-stellar mass (M⋆), can be used to discriminate between bulges with different morphologies or between early- and late-type galaxies. We confirm the existence of two distinct intrinsic relations for bulges of spirals and early-type galaxies, between the bulge luminosity (or absolute magnitude) and Sérsic index, and between the mass of the central black-hole and bulge luminosity, respectively. Within errors, we confirm a unified intrinsic black hole mass-nb relation for all bulges. The parameters of all the aforementioned relations are consistent with values found in other works.


Sponsor: How much does renting a car cost? Car rental fees explained

Summer Sale Buy 4 Get 40% Off