Investigation of silicon dicarbide ($$\hbox {SiC}_2$$) in circumstellar envelopes around carbon-rich AGB stars

Abstract

For known values of rotational and centrifugal distortion constants in conjunction with electric dipole moment, we have calculated energies of 80 rotational levels of para-$$\hbox {SiC}_2$$ and radiative transition probabilities for 299 radiative transitions between the levels. These radiative transition probabilities in conjunction with scaled values for collisional rate coefficients are employed for solving a set of 80 statistical equilibrium equations coupled with 299 equations of radiative transfer. Brightness temperatures of 7 strongest (2 absorption and 5 emission) lines are investigated. These 7 transitions, where 3 are not yet found in any cosmic object, may play important role for identification of $$\hbox {SiC}_2$$ in a cosmic object.