Related papers: Forming the first planetary systems: debris around…
Circumstantial evidence suggests that most known extra-solar planetary systems are survivors of violent dynamical instabilities. Here we explore how giant planet instabilities affect the formation and survival of terrestrial planets. We…
The destiny of planetary systems through the late evolution of their host stars is very uncertain. We report a metal-rich gas disk around a moderately hot and young white dwarf. A dynamical model of the double-peaked emission lines…
The ensemble of now more than 250 discovered planetary systems displays a wide range of masses, orbits and, in multiple systems, dynamical interactions. These represent the end point of a complex sequence of events, wherein an entire…
Large telescopes have allowed astronomers to observe galaxies that formed as early as 850 million years after the Big Bang. We predict when the first star that astronomers can observe formed in the universe, accounting for the first time…
Stellar photometry obtained using the Hubble Space Telescope is used to study the distributions of the number densities of stars of various ages in 12 irregular and dwarf spiral galaxies viewed edge-on. Two subsystems can be distinguished…
The nuclear disc is a dense stellar structure at the centre of the Milky Way, with a radius of $\sim$150 pc. It has been a place of intense star formation in the past several tens of millions of years but its overall formation history has…
Astronomers have discovered that both planets and binaries are abundant throughout the Galaxy. In combination, we know of over 100 planets in binary and higher-order multi-star systems, in both circumbinary and circumstellar configurations.…
Models of the origin of young stars in the Galactic Centre are facing various problems. The most promissing scenario of the star formation in a thin self-gravitating disc naturally forms stars on coherently rotating orbits, but it fails to…
The study of the last stages of planet formation, also known as debris disks, is fundamental to place constrains on the formation of planetary sized bodies. Debris disks are composed of dust and occasionally small amounts of gas, both…
In local disk galaxies such as our Milky Way, older stars generally inhabit a thicker disk than their younger counterparts. Two competing models have attempted to explain this result: one in which stars first form in thin disks that…
Tidal debris around galaxies can yield important clues on their evolution. We have identified tidal debris in 11 early type galaxies (T \leq 0) from a sample of 65 early types drawn from the Spitzer Survey of Stellar Structure in Galaxies…
Stars and planets are the fundamental objects of the Universe. Their formation processes, though related, may differ in important ways. Stars almost certainly form from gravitational collapse and probably have formed this way since the…
Early-type galaxies (ETGs) host a hot ISM produced mainly by stellar winds, and heated by Type Ia supernovae and the thermalization of stellar motions. High resolution 2D hydrodynamical simulations showed that ordered rotation in the…
Planets are thought to form from dust and gas in protoplanetary disks, and debris disks are the remnants of planet formation. Aged a few Myr up to a few Gyr, debris disks have lost their primordial gas, and their dust is produced by…
We study the growth of stellar discs of Milky Way-sized galaxies using a suite of cosmological simulations. We calculate the half-mass axis lengths and axis ratios of stellar populations split by age in isolated galaxies with stellar mass…
The cosmic microwave background and the cosmic expansion can be interpreted as evidence that the Universe underwent an extremely hot and dense phase about 14 Gyr ago. The nucleosynthesis computations tell us that the Universe emerged from…
Most, if not all, disk galaxies have a thin (classical) disk and a thick disk. In most models thick disks are thought to be a necessary consequence of the disk formation and/or evolution of the galaxy. We present the results of a study of…
Several stars show deep transits consistent with discs of roughly 1 Solar radius seen at moderate inclinations, likely surrounding planets on eccentric orbits. We show that this configuration arises naturally as a result of planet-planet…
The number of stars that are known to have debris disks is greater than that of stars known to harbour planets. These disks are detected because dust is created in the destruction of planetesimals in the disks much in the same way that dust…
As part of a stellar population sampling program, a series of photometric probes at various field sizes and depths have been obtained in a low extinction window in the galactic anticentre direction. Very deep CCD frames probe the most…