Absolute measurements of state-to-state rotational energy transfer between CO and H2 at interstellar temperatures

Experimental measurements and theoretical calculations of state-to-state rate coefficients for rotational energy transfer of CO in collision with H-2 are reported at the very low temperatures prevailing in dense interstellar clouds (5-20 K). Detailed agreement between quantum state-selected experiments performed in cold supersonic flows using time-resolved infrared-vacuum-ultraviolet double-resonance spectroscopy and close-coupling quantum scattering calculations confirms the validity of the calculations for collisions between the two most abundant molecules in the interstellar medium.

Automated summary

Experimental measurements and theoretical calculations of rotational energy transfer of CO in collision with H-2 in very low temperatures prevailing in dense interstellar clouds (5-20 K) are reported. The detailed agreement between quantum state-selected experiments performed in cold supersonic flows using time-resolved infrared-vacuum-ultraviolet double-resonance spectroscopy and close-coupling quantum scattering calculations confirms the validity of the calculations for collisions between the two most abundant molecules in the interstellar medium.