PRIMARY DISKS AND THEIR OBSERVATIONAL APPEARANCE IN COLLAPSING MAGNETIC ROTATING PROTOSTELLAR CLOUDS

The collapse of the magnetic rotating protostellar cloud 10 mass is numerically studied. The initial ratios of the thermal, magnetic, and rotational energy to the cloud gravitational energy magnitude are 0.3, 0.2, and 0.01, respectively. The emphasis is on the evolution and properties of the quasi-magnetostatic primary disk formed at the isothermal stage of the collapse. Simulations show that the primary disk size and mass increase during evolution from 1500 au to 7400 au and from 0.3 to 5.2 , respectively. Magnetic fields are quasi-radial in the cloud envelope and quasi-uniform within the primary disk. A toroidal magnetic field is generated behind the front of the fast shock MHD wave propagating from the primary disk boundary and in the region of the outflow formed near the first hydrostatic core. The hierarchical structure of collapsing protostellar clouds can be revealed in observations by the magnetic field geometry and the angular momentum distribution.