Name: Manoel Carlos Vieira de Moraes Junior

IAG-USP

e-mail: mcvmjr(no-spam)astro.iag.usp.br

Partner Contry: BRA

Science Meeting: Yes

User Meeting: None Selected

NGO Staff Meeting: None Selected

Presentation: Yes

Format: Poster

Title: 3D Models of photoionisation in classic novae envelopes

Co-author: Marcos P. Diaz

Co-authors' Institutions: IAG-USP

Abstract:

Classical Novae (CN) are possibly the most important phenomena in the evolution of cataclysmic binaries. In these systems there is mass ejection during the eruptions events and the system is engulfed by a expanding photosphere. The emission lines from CN remnants are belived to be powered by an UV/soft X-rays central source formed by the outburst. Many difficulties in modeling envelopes have been found over the past years. In first order approximation, the observed emission line spectrum depends on the physical conditions in the shell (including the mass spatial distribution and expansion velocity) chemical abundance and properties of ionizing source. About dozen spatially resolved nova shells are currently known. In some of them it has been possible to barely resolve structures and asymmetries. However the presence of globules and their actual size and distribution remain unknown due to limited imaging resolution. The presence of condensations has been a major problem and at same time a solution for understanding photoionization in novae. The photoionization analysis of nebular spectrum is indeed a powerfull method for observing the evolution of the main engine. The slow and bright CN HR Del 1967 and the nova V842 Cen 1986 were observed in the optical using GMOS IFU in 2002 with spectral range from 0,4 to 1 m, a resolution of 300 km/s and spatial resolution of 0,5 arcsec. 2D spectroscopy of shells are the first attempt to study local phenomena in recent nova ejecta. The additional 2D information strongly constraints the geometry. 3D modeling will be pursued by applying Abell type transforms to the observed data grid. Models af central source, shells and knots spectra were performed using CLOUDY c06b (Ferland 2005) and RA3D (Diaz 2001). Simulations had been made to verify the influence of the condensations in the spectral characteristics. The presented simulations consist of improved treatment of structures in this code with the development of physical criteria for the stability and survival of the condensations in the envelope.