Multipole (E1, M1, E2, M2) transition wavelengths and rates between states with n<= 6 in heliumlike carbon, nitrogen, oxygen, neon, silicon, and argon

Transition wavelengths and rates are given for E1, E2, M1, and M2 transitions between singlet and triplet S, P, D, and F states in heliumlike ions of astrophysical interest: carbon, nitrogen, oxygen, neon, silicon, and argon. All possible transitions between states with n <= 6 are considered. Wave functions and energies are calculated using the relativistic configuration-interaction (CI) method including both Coulomb and Breit interactions. For transitions to the ground state, the present theoretical wavelengths agree to five digits with precise measurements.