Title: Modeling the kinematics and star formation history of Andromeda II by a major merger of 
dwarf galaxies

Abstract:
We present an evolutionary model for the origin of Andromeda II, a dSph satellite of M31, 
involving a merger between two disky dwarf galaxies than explains the origin of prolate rotation 
recently detected in the kinematic data for And II. The model is an extension of the scenario 
recently proposed by Lokas et al. The simulation traces the evolution of two initially gas-rich 
disky dwarfs, placed on a radial orbit towards each other with their angular momenta inclined by 
90 deg. After a few Gyr the merger remnant forms a stable triaxial galaxy with rotation mainly 
around the longest axis. This prolate rotation is naturally explained as due to the symmetry of 
the initial configuration which leads to the conservation of angular momentum components along 
the direction of the merger. The merger triggers the formation of new stars, mainly in the center 
of the dwarf, that explains the observed excess of stars in the central stellar density profile of 
And II. The newly formed stars however show a similar kinematics as the old ones, as required 
by the data. The model successfully explains the origin of different stellar populations in And II, 
its star formation history and the kinematics of different populations.