Extensive optical and infrared photometry as well as low and high resolution spectroscopy are used as inputs in deriving robust estimates of the reddening, distance and nature of the progenitor of V838 Mon, the 2002 outbursting event that produced a most spectacular light-echo. The reddening affecting V838 Mon is found to obey the R_V=3.1 law and

Within the framework of the quantum theory of polarized line formation, in the limit of complete frequency redistribution and of the collisionless regime, we derive explicit formulae describing the statistical equilibrium and the radiative emission of a multiterm atom with hyperfine structure, in the presence of an external magnetic field. The

A&A, 417, 751-768 (2004), DOI:10.1051/0004-6361:20034328

We have obtained integral-field spectroscopic data, using the SAURON instrument, of the bar and starbursting circumnuclear region in the barred spiral galaxy M100. From our data, we have derived kinematic maps of the mean velocity and velocity dispersion of the stars and the gas, which we present here. We have also produced maps of the total, [O

We present deep 3.6-8 μm imaging of the Hubble Deep Field-South with the Infrared Array Camera (IRAC) on the Spitzer Space Telescope. We study distant red galaxies (DRGs) at z>2 selected by Js-Ks>2.3 and compare them with a sample of Lyman break galaxies (LBGs) at z=2-3. The observed UV-to-8 μm spectral energy distributions are fitted with stellar

We present Gemini-South observations of the nuclear starburst region of M83, using the CIRPASS near-IR integral-field spectrograph. Spectroscopic diagnostics are used to overcome many of the uncertainties inherent to photometric studies of the star-formation history of the central region of M83. We use Paβ and [Fe II] emission, and absorption in