| Abstract : | We compute a large grid of photo-ionization models using Cloudy Photo-Ionization code that covers a wide range of physical parameters of most of the observed Planetary Nebulae. Our goal is to compare the measured line fluxes of the observed Planetary Nebulae to our model grid to constrain the central star properties, e.g. Effective temperature, Luminosity of the star relative to sun, Ionization parameter, Absolute bolometric magnitude etc. To create the grid, 1. We have varied the elemental abundances (presence of Metals and Gases in the Nebula) of the nebula within a particular range of interest so that we can create a large number of models with same central star properties but different Alpha-element ratios. , 2. We have stopped the calculations when some specific selected lines have reached a predefined intensity ratio limit. When compared with different observed planetary nebulae, our models show very close resemblance in terms of spectral line flux ratios and intensities of the emergent and intrinsic lines. We have tested one of our models with a Planetary Nebula named PN1,in the outer disk of M31 galaxy, in Kwitter et al. 2012 and the our computed model has successfully reproduced the line flux ratios, central star temperature, its luminosity, metallicity and gas phase abundances on terms of He/H, N/O, Ne/O, S/O, Ar/O etc. Further refinement of the model grid is underway along with the comparison with other archival Planetary Nebulae observations. |
