Boxy/peanut bulges in disc galaxies have been associated to stellar bars. We analyse their properties in a large sample of $N$-body simulations, using different methods to measure their strength, shape and possible asymmetry, and then inter-compare the results. Some of these methods can be applied to both simulations and observations. In particular, we seek correlations between bar and peanut properties, which, when applied to real galaxies, will give information on bars in edge-on galaxies, and on peanuts in face-on galaxies.

Aims: Today, large ground-based instruments, like VISIR on the VLT, providing diffraction-limited (about 0.3 arcsec) images in the mid-infrared where strong PAH features appear enable us to see the flaring structure of the disks around Herbig Ae stars. Although great progress has been made in modelling the disk with radiative transfer models able to reproduce the spectral energy distribution (SED) of Herbig Ae stars, the constraints brought by images have not been yet fully exploited. Here, we are interested in checking if these new observational imaging constraints can be accounted for by predictions based on existing models of passive centrally irradiated hydrostatic disks made to fit the SEDs of the Herbig Ae stars. Methods: The images taken by VISIR in the 8.6 and 11.3 microns aromatic features reveal a large flaring disk around HD97048 inclined to the line of sight. In order to analyse the spatial distribution of these data, we use a disk model which includes the most up to date understanding of disk structure and physics around Herbig Ae stars with grains in thermal equilibrium in addition to transiently-heated PAHs. Results: We compare the observed spatial distribution of the PAH emission feature and the adjacent continuum emission with predictions based on existing full disk models. Both SED and spatial distribution are in very good agreement with the model predictions for common disk parameters. Conclusions: We take the general agreement between observations and predictions as a strong support for the physical pictures underlying our flared disk model.

We review here recent numerical results concerning the acceleration and collimation of relativistic outflows from neutron stars, and we discuss their implications for models of magnetars in their hypothesized initial high rotation states. New results with different injection conditions and extending to much larger distance from the central star are also presented and discussed, showing that, only in the case of weakly magnetized winds, collimated outflows are indeed possible. We finally comment on the possibility that newly born magnetars might trigger GRBs, and we show that numerical results do not support such hypothesis.