
TY  - JOUR
A1  - Murphy, JO 
T1  - Structure of a Sequence of Two Zone Polytropic Stellar Models with Indices 0 and 1
JF  - Australian Journal of Physics
JO  - Aust. J.  Phys.
Y1  - 1983
VL  - 36
IS  - 3
SP  - 453
EP  - 462
KW  - 
UR  - https://doi.org/10.1071/PH830453B 
N2  - The structure and physical properties of a sequence of two zone polytropic stellar models, based on E-type composite analytical solutions of the Lane-Emden equation for indices n = 0 and 1, have been determined. The resulting models are characterized by an inner zone of constant density, corresponding to the n = 0 component, and a relatively small envelope with a steep polytropic density gradient and index n = 1. At the surface of these near uniform density composite configurations the physically significant condition p = 0 is always satisfied, a condition which is not fulfilled by the complete poly trope of index n = O. In each model the surface corresponds to the first zero of the associated composite function, which in turn is given by one of the higher order zeros of the E solution of the Lane-Emden equation for n = 1. The radial pulsational properties of these low central condensation type models have also been investigated with the relative amplitudes of radial displacement and density variation given as a function of radial distance for the first six modes of some selected models. Overall, these results establish that the radial displacement amplitudes are only significant in the n = 1 outer layer and accordingly the pulsations can be classified as essentially surface phenomena 
ER  -

