On Possible Segregation of CH4 In CO2 In Interstellar Ice

It is assumed that methane in icy mantles on the surface of interstellar grains is formed and contained prevalently in water-rich environment. Utilizing binary laboratory mixtures of methane (CH4 : H2O = 1 : 10 and CH4 : CO2 = 1 : 5) we obtained a description of methane deformation mode in the B335 protostar. It is shown that most methane is surrounded by CO2 rather than H2O. This is the second object where such a feature has been observed indicating a possibility of methane segregation towards the CO2-rich regions or the important role that CO2 plays in methane formation.