Abstract Details
| Name: Arun Kumar Diwakar Affiliation: ITM Uuniversity Raipur Conference ID: ASI2018_1086 Title : Very flat triaxial mass models of elliptical galaxies Authors and Co-Authors : D. K. Chakraborty Abstract Type : Contributed Talk Abstract Category : Extragalactic astronomy Abstract : deZeeuw and Carollo (1996) presented a simple analytical triaxial mass model which reproduces the observed hotometric properties of ellipticity variation and position angle twist. The potential corresponding to the mass density was also presented. Orbits were calculated in this potential and the underlying numerical distribution as function was shown to exist (Thakur et al 2007). The mass model was used to investigate intrinsic shapes of elliptical galaxies (Thakur & Chakraborty, 2001, Chakraborty et al 2008 and Chakraborty, Diwakar & Pandey, 2011 ). In spite of all these successes, it is realized that this mass model is more appropriate for rounder models. Is case, we consider flat models by taking very small values of the short to long axial ratio, the model presents several issues which need to be considered. We find that in flatter models the constant density surfaces deviate appreciably from ellipsoidal shapes. Another, more important issue is the appearances of narrow region wherein the mass density is negative. Although the absolute values of the negative densities are quite small but nevertheless, negative density region do appear. We find that negative density does not have appreciable effects on projected properties. Addition of extra density terms in the original deZeeuw – Carollo model improves the situation to some extent. |