A&A 366, 418-427 (2001)
DOI: 10.1051/0004-6361:20000256

The orbital evolution of binary galaxies

R. Chan and S. Junqueira

Observatório Nacional, Rua Ganeral José Cristino 77, São Cristóvão, CEP 20921-400, Rio de Janeiro, Brazil University of Massachusetts, Dept. of Astronomy, GRC, Amherst, MA 01003-4525, USA
e-mail: chan@hobby.astro.umass.edu; selma@hobby.astro.umass.edu

(Received 1 August 2000 / Accepted 9 November 2000)

Abstract
We present the results of self-consistent numerical simulations performed to study the orbital circularization of binary galaxies. We have generalized a previous model (Junqueira & de Freitas Pacheco 1994) and confirmed partially their results. The orbital evolution of pairs of galaxies is faster when we consider interacting pairs with contacting "live"galaxy halos but the circularization time remains larger than the Hubble time. Besides, the time behavior of the orbits has changed in comparison with previous work because of tidal forces and dynamical friction acting on the halos.

Key words: galaxies: interactions -- galaxies: kinematics and dynamics -- galaxies: halos

Offprint request: R. Chan

© ESO 2001