Extended analysis of the ν ₁₂ band of ¹² C ₂ H ₄ for astrophysical applications: Line strengths, widths, and shifts

The high-resolution infrared spectra of ¹² C ₂ H ₄ were analyzed in the region of 1360 – 1530 cm ⁻¹ , where the strong ν ₁₂ band is located. 998 line strengths (1491 transitions) were determined from the fit of their line shapes with a Hartmann–Tran profile (J ^max =48 and K _a ^max =17) which is about two times more than in the preceding studies. These data were used in the fit of the effective dipole moment parameters and six such parameters were obtained which reproduce the strengths of the 998 initial lines (1491 transitions) with the d _rms =2.31%. Self–broadening and self-shift coefficients were determined from the multi–spectrum analysis for sets of lines (JK _a =K _a ^′ K _c )←(J ^′ K _a ^′ K _c ^′ ), K _a ^′ =0,1,2,3,4,5 (in general, 253 lines for determination of self-broadening coefficients and 225 lines for determination of self-shift coefficients). The line list of 19186 transitions is documented.