arXiv subjects
Publications and source records attributed to Nicolas Champavert.
We have developed a quick and accurate numerical tool to compute gas cooling whichever its chemical composition.
We present some preliminary results obtained with a new galactic chemodynamical tool under development. In the framework of non-instantaneous recycling approach, we follow the interactions due to star formation and feedback processes. One of the main original features of our code is that we record the abundance evolution of several chemical elements. This allows us to build cooling functions dependent on the real abundances of individual elements. We illustrate the need for such metal-dependent cooling functions using a toy model made of a star cluster embedded in a two-phase gas cloud. Our results suggest that computing cooling rates according to individual abundances of chemical elements can influence the star formation rate.
We have made hydro/N-body simulations with and without star formation to shed some light on the conditions under which a central kinematically cold stellar component (characterized by a velocity dispersion drop or σ-drop) could be created in a hot medium (e.g. a bulge) and survive enough time to be observed. We found that the timescale for a σ-drop formation could be short (less than 500 Myr) whereas its lifetime could be long (more than 1 Gyr) provided that the central region is continuously or regularly fed by fresh gas which leads to a continuous star formation activity. Star formation in the central region, even at a low rate as 1M_{sol} yr^{-1}, is mandatory to sustain a permanent σ-drop by replacing heated particles by new low-σones. We moreover show that as soon as star formation is switched off, the σ-drop begins to disappear.