On the properties of the gas in the galactic halo

The possible mechanisms of creating ions C 4 and Si 4, absorption lines of which are seen in the sectra of stars in the galactic halo at z approximately 1-3 kpc, have been considered. It has been shown that observed quantities of these ions can be explained in the model of the absorbing region in halo with gas temperature T=104 K, ion density n < or approximately 0.01 cm -3, and ionization of elements by ultraviolet background radiation