Zoom-in simulations of Protoplanetary Disks:

Step 1: Follow individual star formation in a 40 pc GMC model over about 10 Myr, using 16 levels (smallest cell size ~120 AU)

Step 2: Follow the accretion process of a selected solar mass star over about 0.2 Myr, using 22 levels (smallest cell size ~ 2 AU)

Step 3: Follow the detailed dynamics over time intervals of a few hundred years, using 29 levels (smallest cell size ~ 0.015 AU)

Visualizations of the mass density and magnetic field lines, at three epochs after the formation of a sink particle that ended up accreting ≈ 1.5 solar masses: 2 kyr after formation (left), 50 kyr after formation (center), and 100 kyr after formation (right). The point of view is essentially face-on in the left hand side panel.

Spatial Resolution of 0.015 AU: