Nova Model Atmopheres

We review the basics physics of nova atmospheres and discuss the physics that has to be included for detailed models of their early spectra. We also present NLTE calculations for model atmospheres of novae during outburst. This fully self‐consistent NLTE treatment for a number of model atoms includes > 5000 NLTE levels and > 57000 NLTE primary transitions. We discuss the implication of departures from LTE for the strengths of the lines in nova spectra. The new results show that our large set of NLTE lines constitute the majority of the total line blanketing opacity in nova atmospheres. Although we include LTE background lines, their effects are small on the model structures and on the synthetic spectra. We demonstrate that the assumption of LTE leads to incorrect synthetic spectra and that NLTE calculations are required for reliably modeling nova spectra. In addition, we show that detailed NLTE treatment for a number of ionization stages of iron changes the results of previous calculations and improves th...