Dissipative phenomena in extended-body interactions

I. Methods: Dwarf galaxies of the Local Group and their synthetic CMDs^⋆

¹ Astronomisches Rechen-Institut, Zentrum für Astronomie der Universität Heidelberg, 69120 Heidelberg, Germany
e-mail: sm2@mssl.ucl.ac.uk
² University College London, Department of Space & Climate Physics, Mullard Space Science Laboratory, Holmbury St. Mary, Dorking Surrey RH5 6NT, UK
³ INAF – Padova Astronomical Observatory, 35122 Padova, Italy
⁴ Astronomy Department, Padova University, 35122 Padova, Italy
⁵ Department of Earth and Space Science, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan

Received: 30 June 2011
Accepted: 15 February 2012

Abstract

Aims. Dissipative phenomena occurring during the orbital evolution of a dwarf satellite galaxy around a host galaxy may leave signatures in the star formation activity and signatures in the colour-magnitude diagram of the galaxy stellar content. Our goal is to reach a simple and qualitative description of these complicated phenomena.

Methods. We develop an analytical and numerical technique able to study the ram pressure, Kelvin-Helmholtz instability, Rayleigh-Taylor, and tidal forces acting on the star formation processes in molecular clouds. We consider it with synthetic colour-magnitude diagram techniques.

Results. We developed a method of investigating the connections between gas consumption processes and star formation processes in the context of the two extended-body interactions, paying special attention to the dwarf galaxies dynamical regime.