Observational manifestations of gaseous baryon dark matter

The paper considers possible observational implications of the presence of dark matter in the Galaxy in the form of dense gas clouds-clumpuscules with masses M-c similar to 10(-3) M-circle dot and radii R-c similar to 3 x 10( 13) cm. The existence of such clouds is implied by modern interpretations o f extreme scattering events-variations in quasar radio fluxes due to refrac tion in dense plasma condensations in the Galactic halo. The rate of collis ions between these clouds is shown to be rather high: from 1 to 10 M-circle dot per year is ejected into the interstellar medium as a result of such c ollisions. The optical continuum and 21-cm emission from hot post-collision gas could be observable. Gas clouds composed of dark matter could be forme d around O stars in an H II region with radius R similar to 30 pc and emiss ion measure EM similar or equal to 20 cmd pc. They could also be observable in the H-alpha line. The evaporation of clumpuscules by external ionizing radiation could be a substantial source of matter for the interstellar medi um. Assuming that the total mass of matter entering the interstellar medium over the Hubble time does not exceed the mass of luminous matter in the Ga laxy, upper limits are found for the cloud radii (R-c < 3.5 x 10(12) cm) an d the contribution of clouds to the surface density of the Galaxy (<50 M-ci rcle dot pc(-2)). Dissipation of the kinetic energy of matter lost by clump uscules could provide an efficient mechanism for heating gas in the Galacti c halo. (C) 2000 MAIK "Nauka/Interperiodica".