The low surface brightness (LSB) universe is one of the last frontiers in observational astronomy. However, uncovering the information contained in ultra-deep imaging is technically challenging. In this contribution, we present one of the fundamental tools of LSB astronomers: correcting for the extended Point-Spread Function (PSF), which is

We study the pitch angles of spiral arms and the frequency and dimensions of inner and outer rings as a function of disk parameters and the amplitude of non-axisymmetries in the S 4G survey. We provide observational evidence for i) the role of strong bars in ring formation/evolution and ii) the dependence between bar and spiral strengths. Yet, the

We present a parametric strong-lensing modeling of the galaxy cluster MS 0440.5+0204 (located at z = 0.19). We have performed a strong-lensing mass reconstruction of the cluster using three different models. The first model uses the image positions of four multiply imaged systems (providing 26 constraints). The second one combines strong-lensing

Almost all chemical elements have been made by nucleosynthetic reactions in various kind of stars and have been accumulated along our cosmic history. Among those elements, the origin of phosphorus is of extreme interest because it is known to be essential for life such as we know on Earth. However, current models of (Galactic) chemical evolution

We have detected CH + and CH molecular absorption lines from the youngcompact planetary nebula IC 4997 from high resolution optical spectra. A high-resolution infra-red (H and K bands) spectrum provides detection of H 2 emission lines among many other lines. The H 2 lines provide an excitation temperature of 2100 K which may result from UV