Maxime Bois, Eric Emsellem, Frédéric Bournaud, Katherine Alatalo, Leo Blitz, Martin Bureau, Michele Cappellari, Roger L. Davies, Timothy A. Davis, P. T. de Zeeuw, Pierre-Alain Duc, Sadegh Khochfar, Davor Krajnović, Harald Kuntschner, Pierre-Yves Lablanche, Richard M. McDermid, Raffaella Morganti, Thorsten Naab, Tom Oosterloo, Marc Sarzi, Nicholas Scott, Paolo Serra, Anne-Marie Weijmans, Lisa M. Young
We study the formation of early-type galaxies (ETGs) through mergers with a
sample of 70 high-resolution numerical simulations of binary mergers of disc
galaxies. These simulations encompass various mass ratios, initial conditions
and orbital parameters. We find that binary mergers of disc galaxies with mass
ratios of 3:1 and 6:1 are nearly always classified as Fast Rotators according
to the Atlas3D criterion: they preserve the structure of the input fast
rotating spiral progenitors. Major disc mergers (mass ratios of 2:1 and 1:1)
lead to both Fast and Slow Rotators. Most of the Slow Rotators hold a stellar
Kinematically Distinct Core (KDC) in their 1-3 central kilo-parsec: these KDCs
are built from the stellar components of the progenitors. The mass ratio of the
progenitors is a fundamental parameter for the formation of Slow Rotators in
binary mergers, but it also requires a retrograde spin for the progenitor
galaxies with respect to the orbital angular momentum. The importance of the
initial spin of the progenitors is also investigated in the library of galaxy
mergers of the GalMer project.
View original:
http://arxiv.org/abs/1201.0885
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