ИСТИНА

We constructed the mass distribution model for the low surface brightness galaxy Malin2 using the photometry from SDSS and GMOS-N data, as well as an available rotation curve. Photometrical and dynamical mass esti- mates are in good agreement and correspond to the dark halo mass fraction of about 80% within four disc radial scalelengths (approximately 100 kpc). The disk surface density extrapolated to the galaxy center is by an order of magnitude lower than that of normal galaxies. We used our dynamical model to obtain radial profiles of the equilibrium disc volume density and gas pressure in the galaxy plane based on available HI and CO data. The observed molecular gas fraction appears to be much higher than in high surface brightness galaxies for a similar gas pressure. Possible reasons of this peculiarity are discussed.