Figure 2 link) The following movie shows one example highlighting the work done in inclining the magneto-hydrodynamic (MHD) models of convection for several angles. As the MHD box (measuring 12,000km across) is inclined, it demonstrates the 'corrugated' nature of granulation whereby the up-flowing hot granules and cool sinking intergranular lanes lie at physically different heights. It is essential to simulate this correctly, as the contributions of the granules and intergranular lanes vary strongly as a function of inclination. Modifying and testing the code to ensure that this was accurately captured in the simulations was a major part of the 1st years' work. (Note: The bright pixel at the bottom-left corner is used to scale the intensities of the image and is not an error.)
Figure 1 link) The movie below shows how the radial (line-of-sight) velocities changes as a function of inclination, and an example of the corresponding line-of-sight velocities in the detailed MHD simulations is also shown (right). A 3rd panel shows the parameterised line profiles at each inclination. At high inclinations the corrugated nature of the convection pattern causes the magnetic lanes and bright points to become obscured, which can be visually appreciated in the inclined MHD simulation at high angles.
Figure 3 link) The following movie shows the model star simulations and the disc-integrated line profiles for an average magnetic field of 200G. 200 simulations are shown here, though in our analysis we have carried out a total of 1,000. The left hand image shows a 'map' of the simulated stellar surface where the intensities are linked to the granule filling-factor for each 12Mm x 12Mm patch. On the right is the resulting line-profile in black, with the line bisector (which represents the mid-point at each position in the line) shown in red and expanded by a factor of 30 to illustrate clearly the bisector's C-shape. In order to see the variations due to convective motions, a portion of the bisector (inset) has been further amplified by 10,000. One can see that the line varies by ~50 cm/s - inline with predictions for solar granulation induced radial velocity variability.