AMIGA: very low environment galaxies in the local universe Verley, Simon Combes, F. Verdes-Montenegro, L. Leon, S. Odewahn, S. C. Bergond, G. Espada Fernández, Daniel García, E. Lisenfeld , Ute Sabater, J. Sulentic, J. AMIGA (Analysis of the interstellar Medium of Isolated Galaxies) Galaxies ISM The evolutionary history of galaxies is thought to be strongly conditioned by the environment. In order to quantify and set limits on the role of nurture one must identify and study an isolated sample of galaxies. But it is not enough to identify a small number of the "most isolated" galaxies. We begin with 950 galaxies from the Catalogue of Isolated Galaxies (Karachentseva 1973) and reevaluate isolation using an automated star-galaxy classification procedure on large digitised POSS-I fields. We define, compare and discuss various criteria to quantify the degree of isolation for these galaxies: Karachentseva's revised criterion, local surface density computations and an estimation of the external tidal force affecting each isolated galaxy. Comparison of multi-wavelength ISM properties, in particular the H$\alpha$ emission line, will allow us to separate the influence of the environment from the one due to the initial conditions at formation. 2013-10-11T07:24:39Z 2013-10-11T07:24:39Z 2006 conference output Verley, S.; et al. AMIGA: very low environment galaxies in the local universe. In: F. Casoli, et al. (eds.), SF2A 2005: Seamine de l'Astrophysique Francaise. Strasbourg (France), 27 june- 1 july 2005. pp. 237-238. [http://hdl.handle.net/10481/28416] arXiv:astro-ph/0601118v1 http://hdl.handle.net/10481/28416 eng http://creativecommons.org/licenses/by-nc-nd/3.0/ open access Creative Commons Attribution-NonCommercial-NoDerivs 3.0 License EDP Sciences