Volume 510, February 2010
|Number of page(s)||4|
|Published online||10 February 2010|
Influence of baryonic physics on the merger timescale of galaxies in N-body/hydrodynamical simulations
Key Laboratory for Research in Galaxies and Cosmology, Shanghai Astronomical Observatory,
Nandan Road 80, Shanghai, 200030, PR China
2 Graduate School of the Chinese Academy of Sciences, 19A, Yuquan Road, Beijing, PR China
Accepted: 7 November 2009
In previous work, we studied the merger timescale of galaxies in a high-resolution cosmological hydro/N-body simulation. We now investigate the potential influence of uncertainties in the numerical implementation of baryonic physics on the merger timescale. The simulation used in the previous work was affected by the overcooling problem, which caused the central galaxies of large halos to be too massive. This might be responsible for producing a shorter merger timescale than that in the real universe. We perform a similar simulation, but in which the stellar mass is reduced significantly to model another extreme case of low stellar mass. Our result indicates that in this case the merger timescale is systematically higher than that we measured before. However, the difference in these two cases is only about , except for satellites in nearly radial orbits where the difference is larger, reaching 23 percent. Since the two simulations correspond to both the low and high stellar mass limiting cases, and nearly radial orbits account for only a small part of the satellites' orbits, our results indicate that the fitting formula that we presented previously is applicable to good accuracy.
Key words: galaxies: clusters: general / galaxies: kinematics and dynamics / methods: numerical
© ESO, 2010
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.