The Intergalactic Stellar Population from Mergers of Elliptical Galaxies with Dark Matter halos - Astrophysics > Cosmology and Nongalactic AstrophysicsReport as inadecuate




The Intergalactic Stellar Population from Mergers of Elliptical Galaxies with Dark Matter halos - Astrophysics > Cosmology and Nongalactic Astrophysics - Download this document for free, or read online. Document in PDF available to download.

Abstract: We present simulations of dry-merger encounters between pairs of ellipticalgalaxies with dark matter halos. The aim of these simulations is to study theintergalactic stellar populations produced in both parabolic and hyperbolicencounters. We model progenitor galaxies with total-to-luminous mass ratiosM T-M L 3 and 11. The initial mass of the colliding galaxies are chosen so thatM 1-M 2 and 10. The model galaxies are populated by particles representingstars, as in Stanghellini et al. 2006, and dark matter. Merger remnantsresulting from these encounters display a population of unbounded particles,both dark and luminous. The number of particles becoming unbounded depends onorbital configuration, with hyperbolic encounters producing a larger luminousintracluster population than parabolic encounters. Furthermore, in simulationswith identical orbital parameters, a lower M T-M L of the colliding galaxiesproduces a larger fraction of unbounded luminous particles. For each modeledcollision, the fraction of unbounded to initial stellar mass is the same in allmass-bins considered, similarly to what we found previously by modelingencounters of galaxies without dark halos. The fraction of intergalactic tototal luminosity resulting from our simulations is ~ 4% and ~ 6% fordark-to-bright mass rations of 10 and 2 respectively. These unbounded-to-totalluminous fractions are down from 17 % that we had previously found in the caseof no dark halos. Our results are in broad agreement with intergalactic lightobserved in groups of galaxies, while the results of our previous modelswithout dark halos better encompass observed intracluster populations. Wesuggest a possible formation scenario of intergalactic stars.



Author: A.C. Gonzalez-Garcia, L. Stanghellini, A. Manchado

Source: https://arxiv.org/







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