Recent investigations have provided evidences that many massive (M_* > 10^{11} M_&sun;) spheroid galaxies in the early universe (z ≥ 1.5) were extremely compact (r_e ˜ 1 kpc). According to some galaxy formation theories, a fraction of these massive galaxies in the local Universe would represent surviving relics of the high-z massive galaxies. We

Not Available

We have reproduced some sunspot wave signatures obtained from spectropolarimetric observations through 3D MHD numericalsimulations. The results of the simulations arecompared with the oscillations observed simultaneously at different heights from the SiI lambda10827Å line, HeI lambda10830Å line, the CaII H core and the FeI blends at the wings of

We present a summary of results obtained by Poidevin & Bastien (2006) in the GF-9 core region. Multi-scale analysis is used and suggests that an original poloidal magnetic field could have been twisted by a rotating elongated (core+envelope) structure.

L-type ultra-cool dwarfs are known to have a dusty atmosphere. Surface heterogeneities, due to cloud patterns or rotationally-induced oblateness, would result in an imperfect polarization cancellation and a small, but non-zero net polarization. The measurement of linear polarization could shed light on the dust distribution and oblateness of those

Not Available