Related papers: Inner density waves: The need for two-dimensional …
Two-dimensional infrared (2DIR) spectroscopy is widely used to study molecular dynamics but it is typically restricted to solid and liquid phase samples and modest spectral resolution. Only recently, its potential to study gas-phase…
We discuss some recent integral field spectroscopy using the SAURON instrument of a sample consisting of 24 early-type spirals, part of the SAURON Survey, and 18 late-type spirals. Using 2-dimensional maps of their stellar radial velocity,…
We give an introduction into the observational technique of integral field or 3D spectroscopy. We discuss advantages and drawbacks of this type of observations and highlight a few science projects enabled by this method. In the second part…
This is the first article in a series of three dealing with the exploitation of speckle for imaging purposes. Speckle is the complex interference wave-field produced by a random distribution of un-resolved scatterers. In this paper, we show…
Observations at long wavelengths, in the wide interval from a few to 1000 micron, are essential to study diffuse media in galaxies, including all kinds of atomic, ionic and molecular gases and dust grains. Hence they are particularly suited…
Pulsar dynamic spectra exhibit high visibility fringes arising from interference between scattered radio waves. These fringes may be random or highly ordered patterns, depending on the nature of the scattering or refraction. Here we…
Multi-wavelength spectroscopy can be used to constrain the dust and gas properties in debris disks. Circumstellar dust absorbs and scatters incident stellar light. The scattered light is sometimes resolved spatially at visual and…
Infrared imaging properties of dusty winds around late-type stars are investigated in detail, employing a self-consistent model that couples the equations of motion and radiative transfer. Because of general scaling properties, the angular…
The density-wave theory of spiral structure proposes that star formation occurs in or near a spiral-shaped region of higher density that rotates rigidly within the galactic disk at a fixed pattern speed. In most interpretations of this…
Diffuse interstellar bands (DIBs) hold a lot of information about the state and the structure of the ISM. Structure can most directly be observed by extensive spectroscopic surveys, including surveys of stars where DIBs are especially…
Clusters of galaxies are used in a variety of ways to do cosmology. Some of them are presented here. Their X-ray emitting gas allows us to determine the baryon fraction, dark matter distribution and the matter density $\Omega_{m}$ of the…
Multi-frequency radio polarimetry of the diffuse Galactic synchrotron background gives new viewpoints on the Galactic magnetic field. Rotation measure maps reveal magnetic structures on arcminute to degree scales, such as a ring in…
The Galactic interstellar turbulence affects the density distribution and star formation. We introduce a new method of measuring interstellar turbulent density spectra by using the dispersion measures (DMs) of a large sample of pulsars.…
Significant fraction of barred galaxies hosts secondary bar-like structures on optical and NIR images. The circumnuclear dynamics of double-barred objects are still not well understood, observational data concerning kinematics are…
A critical review of the very long-standing problem of the diffuse interstellar bands is presented with emphasis on spectroscopic aspects of observational, modelling and laboratory-based research. Some research themes and ideas that could…
A new spin wavelet transform on the sphere is proposed to analyse the polarisation of the cosmic microwave background (CMB), a spin $\pm 2$ signal observed on the celestial sphere. The scalar directional scale-discretised wavelet transform…
In recent years, a rapidly growing literature has focussed on the construction of wavelet systems to analyze functions defined on the sphere. Our purpose in this paper is to generalize these constructions to situations where sections of…
We propose a new dynamical mechanism to account for the bar off-centering observed in many barred galaxies. It is based on the presence of a m=1 density wave, non-linearly excited by the strong m=2 component due to the linearly unstable bar…
Optical instruments for measuring surface-wave characteristics provide a better spatial and temporal resolution than other methods, but they face difficulties while converting the results of indirect measurements into absolute levels of the…
The local space density of galaxies as a function of their basic structural parameters --like luminosity, surface brightness and scalesize-- is still poorly known. Our poor knowledge is mainly the result of strong selection biases against…