SIMBAD references

We present ISO-SWS spectra of the O-rich Mira variable R Cas, showing CO₂ in absorption and emission, and H₂O in absorption. The CO₂ absorption feature is the 01¹0-00⁰0 ro-vibrational band at 14.97µm . The emission features are the 10⁰0-01¹0 and 11¹0-02²0 ro-vibrational transitions at 13.87 and 13.48µm respectively. The water absorption spectrum shows the ν₁ and ν₃ ro-vibrational bands in the 2.75-3µm region. Using LTE models, we derive physical parameters for the features. We find the CO₂ emission temperature to be ∼1100 K. We discuss the nature of the CO₂ feature at 15µm and show that it can be modeled as an emission/absorption band by deviating from thermal equilibrium for the population of the 01¹0 vibrational level. The H₂O absorption spectrum is shown to arise from gas at different temperatures, but can be fit reasonably well with two components at T=950 K and T=250 K. The CO₂ emission and hot H₂O absorption temperatures are similar, suggesting that these features probe the same region of the inner envelope. We discuss the inner envelope chemistry using molecular equilibrium calculations and recent modeling work by Duari et al. (1999), and find our observations consistent with the results. We also report the detection of the CO₂ 01¹0-00⁰0 ro-vibrational band in absorption towards another oxygen-rich Mira, IRC+10011.