Creating lenticular galaxies with mergers

• Published in: Proceedings of the International Astronomical Union Vol. 11; no. S321; pp. 114 - 116
• Main Authors: Querejeta, Miguel, Eliche-Moral, M. Carmen, Tapia, Trinidad, Borlaff, Alejandro, van de Ven, Glenn, Lyubenova, Mariya, Martig, Marie, Falcón-Barroso, Jesús, Méndez-Abreu, Jairo, Zamorano, Jaime, Gallego, Jesús
• Format: Journal Article
• Language: English
• Published: Cambridge, UK Cambridge University Press 01.03.2016
• Subjects: Angular momentum; Astronomy; Computer simulation; Contributed Papers; Disk galaxies; Galaxy mergers & collisions; Local group (astronomy); Photometry; Spiral galaxies; Spirals; Star & galaxy formation; Star formation; Universe; galaxies: structure; galaxies: elliptical and lenticular; galaxies: kinematics and dynamics; galaxies: evolution; galaxies: interactions
• ISSN: 1743-9213; 1743-9221
• DOI: 10.1017/S1743921316009030

Lenticular galaxies (S0s) represent the majority of early-type galaxies in the local Universe, but their formation channels are still poorly understood. While galaxy mergers are obvious pathways to suppress star formation and increase bulge sizes, the marked parallelism between spiral and lenticular galaxies (e.g. photometric bulge–disc coupling) seemed to rule out a potential merger origin. Here, we summarise our recent work in which we have shown, through N-body numerical simulations, that disc-dominated lenticulars can emerge from major mergers of spiral galaxies, in good agreement with observational photometric scaling relations. Moreover, we show that mergers simultaneously increase the light concentration and reduce the angular momentum relative to their spiral progenitors. This explains the mismatch in angular momentum and concentration between spirals and lenticulars recently revealed by CALIFA observations, which is hard to reconcile with simple fading mechanisms (e.g. ram-pressure stripping).