ROTATIONAL EXCITATIONS OF H2 IN NONTHERMAL ASTROPHYSICAL PLASMAS

This paper investigates the nonthermal effects of electrons on the rotational excitations of the hydrogen molecule in astrophysical Lorentzian plasmas. The J = 0 → 2 and J = 1 → 3 rotational excitation cross sections are employed in order to obtain the rotational excitation rates of the hydrogen molecule as functions of the spectral index and temperature. It is shown that the rotational excitation rates of H2 in non-Maxwellian plasmas are smaller than those in Maxwellian plasmas in low-temperature regions (HI region). However, in high-temperature regions the rotational excitation rates of H2 in non-Maxwellian plasmas are greater than those in Maxwellian plasmas. It is found that the rotational excitation temperature for the peak position of the excitation rate decreases with the decreasing nonthermal character of the plasma. It is also shown that the nonthermal effect on the rotational excitation for the principal transition J = 0 → 2 is stronger than that for the J = 1 → 3 transition.