This study presents deep optical surface photometry in the R-band for the three spiral galaxies NGC 1003, NGC 5533, and NGC 6674. The luminosity profiles, derived by fitting ellipses to the isophotes, are decomposed into bulge and disk contributions using the method proposed by Kent (1986). The intrinsic bulge and disk axis ratios, used in the

We present a deep multicolor NIR survey that we are currently undertaking at the Instituto de Astrofísica de Canarias (Spain). The aim of the survey is obtain deep star counts in selected areas distributed along the Galactic plane to analyze the large scale structure of the Milky Way and the galactic components, in particular the Galactic bar. We

We classify nontrivial deformations of the standard embedding of the Lie algebra $Vect(S^1)$ of smooth vector fields on the circle, into the Lie algebra~$PD(S^1)$ of pseudodifferential symbols on $S^1$. This approach leads to deformations of the central charge induced on $Vect(S^1)$ by the canonical central extension of $PD(S^1)$. As a result we

We have acquired imaging of the bipolar outflow M2-9 in the transitions [O III] λ5007, H I λ6563, [N II] λ6584, and [S II] λλ6717, 6731. As a result, we are able to map both excitation and density over the face of the nebula. We find that underlying densities in the lobes increase to ne~1.6x103 cm-3 at distances rp~12"-15" from the central star

The one-point probability distribution function (PDF) of the matter density field in the universe is a fundamental property that plays an essential role in cosmology for estimates such as gravitational weak lensing, non-linear clustering, massive production of mock galaxy catalogues, and testing predictions of cosmological models. Here we make a

Context. H II regions in the arms of spiral galaxies are indicators of recent star-forming processes. They may have been caused by the passage of the density wave or simply been created by other means near the arms. The study of these regions may give us clues to clarify the controversy about the existence of a triggering scenario, as proposed in