Related papers: Dynamical mass distribution and velocity structure…
We present results of N-body simulations aimed at understanding the dynamics of young stars near the Galactic center. Specifically, we model the inspiral of a cluster core containing an intermediate mass black hole and $N \sim 50$ cluster…
Constraints on the Galactic bulge/bar structure and formation history from stellar kinematics and metallicities mainly come from relatively high-latitude fields (|b|>4) where a complex mix of stellar population is seen. We aim here to…
Knowing the metallicity distribution of stars in the Galactic Centre has important implications for the formation history of the Milky Way nuclear star cluster. However, this distribution is not well known, and is currently based on a small…
We quantify the structure of a very large number of Galactic open clusters and look for evidence of mass segregation for the most massive stars in the clusters. We characterise the structure and mass segregation ratios of 1276 clusters in…
We present a method for fitting orbit-superposition models to the kinematics of discrete stellar systems when the available stellar sample has been filtered by a known selection function. The fitting method can be applied to any model in…
Recent large scale surveys of galactic bulge stars allowed to build a detailed map of the bulge kinematics. The bulge exhibits cylindrical rotation consistent with a disky origin which evolved through bar driven secular evolution. However…
We performed a spectroscopic survey of nearly 700 stars probing the galactic thick disc far from the solar neighbourhood towards the galactic coordinates (l~277, b~47). The derived effective temperatures, surface gravities and overall…
We report the detection of the Galactic nuclear disc in line-of-sight kinematics of stars, measured with infrared spectroscopy from APOGEE. This stellar component of the nuclear disc has an extent and rotation velocity V ~ 120kms comparable…
We describe a novel framework to model galaxy spectra with two cospatial stellar populations, such as may represent a bulge & bar or thick & thin disc, and apply it to APOGEE spectra in the inner $\sim$2 kpc of M31, as well as to stacked…
We examine the effect of an accretion disc on the orbits of stars in the central star cluster surrounding a central massive black hole by performing a suite of 39 high-accuracy direct N-body simulations using state-of-the art software and…
It is widely believed that star clusters form with low star formation efficiencies. With the onset of stellar winds by massive stars or finally when the first super nova blows off, the residual gas is driven out of the embedded star…
The kinematics of the Milky Way bulge is known to be complex, reflecting the presence of multiple stellar components with distinct chemical and spatial properties. In particular, the bulge hosts a bar structure exhibiting cylindrical…
We explore the nucleus of the nearby 10$^9M_{\odot}$~early-type galaxy (ETGs), NGC~404, using Hubble Space Telescope (HST)/STIS spectroscopy and WFC3 imaging. We first present evidence for nuclear variability in UV, optical, and infrared…
Our Galaxy is known to contain a central boxy/peanut-shaped bulge, yet the importance of a classical, pressure-supported component within the central part of the Milky Way is still being debated. It should be most visible at low…
We combine in a self-consistent way the constraints from both gravitational lensing and stellar kinematics to perform a detailed investigation of the internal mass distribution, amount of dark matter, and dynamical structure of the 16…
We use a sample of 938 red clump giant stars located in the direction of the galactic long bar to study the chemistry of Milky Way bar stars. Kinematically separating stars on bar orbits from stars with inner disc orbits, we find that stars…
The origin of the population of very massive stars observed within $\sim 0.4$ pc of the supermassive black hole in the Galactic Centre is a mystery. Tidal forces from the black hole would likely inhibit {\it in situ} star formation whilst…
The dynamics of two massive black holes in a rotationally supported nuclear disc of 10^8 solar masses is explored using N-Body/SPH simulations. Gas and star particles are co-present in the disc. Described by a Mestel profile, the disc has a…
The Milky Way's central parsec is a highly extinguished region with a population of high-proper-motion stars. We have tracked 145 stars for $\sim$10 years at wavelengths between 1 and 4 microns to analyze extinction effects in…
We study Milky Way kinematics using a sample of 18.8 million main-sequence stars with r<20 and proper-motion measurements derived from SDSS and POSS astrometry, including ~170,000 stars with radial-velocity measurements from the SDSS…