Related papers: Distribution and Content of Dust in Overlapping Ga…
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…
An update of the set of low surface brightness galaxies is presented which can be used to set constraints on the otherwise ambiguous decompositions of their rotation curves into contributions due to the various components of the galaxies.…
Whenever gas is blown out of a galaxy, chances are that it contains some cosmic dust. This dust is an important part of the metals budget for the circumgalactic and intergalactic media, and traces the outflow and stripping history of the…
The stellar and dust content of spiral galaxies as function of radius has been investigated using near-infrared and optical broadband surface photometry of 86 face-on spiral galaxies. Colors of galaxies correlate with the azimuthally…
In a large scale view of the universe, galaxies are the basic unit of structure. A typical bright galaxy may contain 100 billion stars and span tens of thousands of light years, but the empty expanses between the galaxies are much larger…
There is now ample evidence that the interstellar thick disks of spiral galaxies are dusty. Although the majority of extraplanar gas in the first few kiloparsecs above the plane of a spiral galaxy is matter that has been expelled from the…
More than half of the volume of our Universe is occupied by cosmic voids. The lensing magnification effect from those under-dense regions is generally thought to give a small dimming contribution: objects on the far side of a void are…
Various cosmological applications of galaxy clusters are presented. Clusters are used to determine the baryon fraction, dark matter distribution and the matter density of the universe. They also contain a wealth of information about…
The opacity of a spiral disk due to dust absorption influences every measurement we make of it in the UV and optical. Two separate techniques directly measure the total absorption by dust in the disk: calibrated distant galaxy counts and…
The severity of the mass discrepancy in spiral galaxies is strongly correlated with the central surface brightness of the disk. Progressively lower surface brightness galaxies have ever larger mass discrepancies. No other parameter…
Analysing the weak lensing distortions of the images of faint background galaxies provides a means to constrain the average mass distribution of cluster galaxies and potentially to test the extent of their dark matter haloes as a function…
We investigate how significant the spiral structure is on calculations concerning radiative transfer in dusty spiral galaxies seen edge-on. The widely adopted exponential disk model (i.e. both the stars and the dust are distributed…
We review recent progress in high-resolution imaging of scattered light from disks around young stellar objects. Many new disks have been discovered or imaged in scattered light, and improved instrumentation and observing techniques have…
A large fraction of known galaxy-lens systems require a component of external shear to explain the observed image geometries. In most cases, this shear can be attributed to a nearby group of galaxies. We discuss how the dark-matter mass…
The different regimes of gravitational lensing constitutes an interesting tool in order to map the mass distribution in galaxy clusters on different scales. In this proceedings article, I review some work I have performed on this topic.…
Gravitational lensing is one of a number of methods used to probe the distribution of dark mass in the Universe. On galactic scales, complementary techniques include the use of stellar kinematics, kinematics and morphology of the neutral…
While galactic bulges may contain no significant dust of their own, the dust within galaxy discs can strongly attenuate the light from their embedded bulges. Furthermore, such dust inhibits the ability of observationally-determined…
In order to investigate the nature and origin of dust in elliptical galaxies, a method for the dust mass evaluation, which accounts for the dust temperature distribution, is here presented and discussed. The derived dust masses turn out to…
The mass function of galaxies and clusters of galaxies can be derived observationally based on different types of observations. In this study we test if these observations can be combined to a consistent picture which is also in accord with…
Disk galaxies contain a large amount of interstellar dust, which affects the projection of kinematic quantities. We investigate in detail the effects of dust extinction on the mean projected velocity and the projected velocity dispersion.…