Related papers: The Galactic Underworld: The spatial distribution …
A dark star cluster (DSC) is a system in which the cluster potential is dominated by stellar remnants, such as black holes and neutron stars having larger masses than the long-lived low-mass stars. Due to mass segregation, these remnants…
I review the up-to-date status on the properties of the Dark Matter density distribution around Galaxies. The rotation curves of spirals all conform to a same Universal profile which can be uniquely decomposed as the sum of an exponential…
The centres of galaxies host nuclear stellar clusters, supermassive black holes, or both. The origin of this dichotomy is still a mystery. Nuclear stellar clusters are the densest stellar system in the Universe, so they are ideal places for…
The inspiral and merger of two black holes produces a remnant black hole with mass and spin determined by the properties of its parent black holes. Using the inferred population properties of component black holes from the first two and a…
A massive young star cluster, initially embedded in its parent molecular cloud, will spiral into the Galactic Center from $\lta 30m_6^{1/2}\pc$ during the life-time of its most massive stars, if the combined total mass is $\sim…
Context. A significant fraction (~30%) of massive stars in our Galaxy are moving supersonically through the interstellar medium, which strongly governs their location at the time they end their lives, e.g. die as a supernova and give birth…
We study the detailed structure of galaxies at redshifts z > 2 using cosmological simulations with improved modeling of the interstellar medium and star formation. The simulations follow the formation and dissociation of molecular hydrogen,…
Supermassive black holes in the centre of galaxies dominate the gravitational potential of their surrounding stellar clusters. In these dense environments, stars follow nearly Keplerian orbits, which get slowly distorted as a result of the…
Most population studies of pulsars have hitherto focused on the disc of the Galaxy, the Galactic centre, globular clusters, and nearby galaxies. It is expected that pulsars, by virtue of their natal kicks, are also to be found in the…
The mid infrared spectra of the starbursts show the 9.7$\mu m$ silicate absorption feature and strong mid infrared emission bands centered at 6.2, 7.7, and 11.3 $\mu$m. Illustrative models of the {\it active} galaxies are presented: As the…
Observations of the galactic center revealed a population of young massive stars within 0.4 pc from Sgr A* -- the presumed location of a supermassive black hole. The origin of these stars is a puzzle as their formation in citu should be…
Most stars form in compact, dense embedded clusters with memberships ranging from a dozen stars to many millions of stars. Embedded clusters containing more than a few hundred stars also contain O stars that disrupt the nebula abruptly.…
The differences in the relationships between the physical parameters and the chemical-element abundances in accreted globular star clusters and those formed inside the Galaxy have been investigated. The information on the supposed formation…
Our Galactic Center hosts over 10% of the known massive stars in the Galaxy. The majority of these stars are located in three particularly massive clusters that formed within the past 5 Myr. While these clusters are extraordinary, their…
Galaxies, diffuse gas, and dark matter make up the cosmic web that defines the large-scale structure of the Universe. We constrained the joint distribution of these constituents by cross-correlating galaxy samples binned by stellar mass…
Quasars are associated with and powered by the accretion of material onto massive black holes; the detection of highly luminous quasars with redshifts greater than z = 6 suggests that black holes of up to ten billion solar masses already…
To study systematically the evolution on the angular extents of the galaxy, ICM, and dark matter components in galaxy clusters, we compiled the optical and X-ray properties of a sample of 340 clusters with redshifts $<0.5$, based on all the…
The majority of massive black holes (MBHs) likely hosted gas discs during their lifetimes. These could either be long-lived active galactic nuclei (AGN) discs, or shorter-lived discs formed following singular gas infall events, as was…
The paucity of old isolated accreting neutron stars in ROSAT observations is used to derive a lower limit on the mean velocity of neutron stars at birth. The secular evolution of the population is simulated following the paths of a…
We study galactic enrichment with rapid neutron capture (r-process) elements in cosmological, magnetohydrodynamical simulations of a Milky Way-mass galaxy. We include a variety of enrichment models, based on either neutron star mergers or a…