Related papers: Testing the Galactic Centre potential with S-stars
The kinematical properties of elliptical galaxies formed during the mergers of equal mass, stars+gas+dark matter spiral galaxies are compared to the observed low velocity dispersions found for planetary nebulae on the outskirts of…
We present direct observational constraints on the orbital distribution of the stars in the giant elliptical NGC 2320. Long-slit spectra along multiple position angles are used to derive the stellar line-of-sight velocity distribution…
The nuclear star cluster surrounding the massive black hole at the Galactic Centre consists of young and old stars, with most of the stellar mass in an extended, cuspy distribution of old stars. The compact cluster of young stars was…
The galaxy distribution in dark matter-dominated halos is expected to approximately trace the details of the underlying dark matter substructure. In this paper we introduce halo `core-tracking' as a way to efficiently follow the small-scale…
We use a new non-parametric Bayesian approach to obtain the most probable mass distributions and circular velocity curves along with their confidence ranges, given deprojected density and temperature profiles of the hot gas surrounding…
We report on the nature of prominent sources of light and shadow in the Galactic Center. With respect to the Bremsstrahlung X-ray emission of the hot plasma in that region the Galactic Center casts a 'shadow'. The 'shadow' is caused by the…
An active stage of relativistic astrophysics started in 1963 since in this year, quasars were discovered, Kerr solution has been found and the first Texas Symposium on Relativistic Astrophysics was organized in Dallas. Five years later, in…
The standard framework within which cosmological measurements are confronted and interpreted nowadays, called Lambda Cold Dark Matter, presents a Universe dominated by unknown forms of energy and matter. My Thesis is devoted to investigate…
Dark matter comprises the bulk of the matter in the universe but its particle nature and cosmological origin remain mysterious. Knowledge of the dark matter density distribution in the Milky Way Galaxy is crucial to both our understanding…
The Milky Way's Galactic Center harbors a gamma-ray excess that is a candidate signal of annihilating dark matter. Dwarf galaxies remain predominantly dark in their expected commensurate emission. In this work we quantify the degree of…
This paper has been withdrawn temporarily by the authors. As stars close to the galactic centre have short orbital periods it has been possible to trace large fractions of their orbits in the recent years. Previously the data of the orbit…
Dynamical interactions between stars and the super massive black hole Sgr A* at the Galactic Centre (GC) may eject stars into the Galactic halo. While recent fast ejections by Sgr A* have been identified in the form of hypervelocity stars…
Particle dark matter near the galactic center is accreted by the central black hole into a dense spike, strongly enhancing its annihilation rate. Searching for its annihilation products may give us information on the presence or absence of…
(abridged) The velocity distribution f(v) of nearby stars is estimated, via a maximum- likelihood algorithm, from the positions and tangential velocities of a kinematically unbiased sample of 14369 stars observed by the HIPPARCOS satellite.…
We consider a simple extension of the type-II two-Higgs-doublet model by introducing a real scalar as a candidate for dark matter in the present Universe. The main annihilation mode of the dark matter particle with a mass of around $31-40$…
In this work, we combine ellipticity and major axis position angle measurements from the Sloan Digital Sky Server Data Release 16 (SDSS DR16) with the group finder algorithm of Rodriguez \& Merch\'an to determine the alignment of the…
Observational studies of nearby galaxies have demonstrated correlations between the mass of the central supermassive black holes (BHs) and properties of the host galaxies, notably the stellar bulge mass or central stellar velocity…
Polar ring galaxies, where matter is in equilibrium in perpendicular orbits around spiral galaxies, are ideal objects to probe the 3D shapes of dark matter halos. The conditions to constrain the halos are that the perpendicular system does…
The Galactic center is an interesting region for high-energy (0.1-100 GeV) and very-high-energy (E > 100 GeV) gamma-ray observations. Potential sources of GeV/TeV gamma-ray emission have been suggested, e.g., the accretion of matter onto…
We present the 21-cm rotation curve of the nearby galaxy M33 out to a galactocentric distance of 16 kpc (13 disk scale-lengths). The rotation curve keeps rising out to the last measured point and implies a dark halo mass larger than 5…