We present the first results of a 3D numerical modeling of linear MHD wave propagation in a realistic sunspot model. In our simulations, a piston located at the base of the photosphere generates waves with a certain period. The ratio between the acoustic and the Alfven speed, cS /vA, decreases from much larger than one at the photosphere to much

We present new results following up on our deep near-IR imaging of the strong lensing clusters Abell 1835 and AC114, which has allowed us to identify 13 star forming galaxy candidates at z>7 (Richard et al. 2006, A&A in press, [astro-ph/ 0606134]). Our previous optical and near-IR observations (mostly from WFPC2/HST, CFHT, ISAAC/VLT) have now been

The 1.5m solar telescope GREGOR is being constructed at Tenerife, Spain. Its purpose is to observe with high spatial and spectral resolution small-scale dynamic magnetic features on the Sun. The telescope is completely open with retractable dome and actively cooled primary mirror made of silicon carbide to minimize thermal effects on the image

Interpretation of linearly polarized parameters of the spectral lines of the second solar spectrum permits to obtain information about the magnetic field vector of the medium where the spectral lines are formed, provided suitable theoretical and numerical methods be applied to extract the physical information. This linear polarization is modified

To study the small-scale dynamic processes of magneto-convection in the solar photosphere in more detail than currently achieveable, not only the spatial resolution has to be increased, but also the information content of observations. In order to do so, several wavelengths and spectral lines must be observed simultaneously. This is often achieved

Class II methanol Masers and ultracompact HII regions (UCHII) trace regions of massive star formation. We have carried out mid-IR imaging of a selected number of star forming complexes traced by UCHII and methanol maser emission to determine their large scale properties. The mid-IR images from 8 to 20 micron were obtained with the mid-IR camera CID