相关论文: Applying Liouville's Theorem to Gaia Data

Context. Astrometric gravitational microlensing can be used to determine the mass of a single star (the lens) with an accuracy of a few percent. To do so, precise measurements of the angular separations between lens and background star with…

We examine the problem tidally-induced mass loss from collisionless systems such as dark matter haloes. We develop a model for tidal mass loss, based upon the phase space distribution of particles, which accounts for how both tidal and…

The dynamics of a quantum-many body system subject to measurements is naturally described by an ensemble of quantum trajectories, which can feature measurement-induced phase transitions (MIPTs). This phenomenon cannot be revealed through…

Using hydrodynamical simulations, we study how well the underlying gravitational potential of a galaxy cluster can be modelled dynamically with different types of tracers. In order to segregate different systematics and the effects of…

Gravitational waves from the merger of two neutron stars cannot be easily distinguished from those produced by a comparable-mass mixed binary in which one of the companions is a black hole. Low-mass black holes are interesting because they…

We use the distribution of accreted stars in SDSS-Gaia DR2 to demonstrate that a non-trivial fraction of the dark matter halo within Galactocentric radii of 7.5-10 kpc and $|z| > 2.5$ kpc is in substructure, and thus may not be in…

The gravitational pull of an unseen companion to a luminous star is well-known to cause deviations to the parallax and proper motion of a star. In a previous paper in this series, we argue that the astrometric mission Gaia can identify…

We study the distribution of the Milky Way satellites stellar and dark matter debris. For the first time we address the question of the tidal disruption of satellites in simulations by utilising simultaneously a) a realistic set of orbits…

We study the orbital phase-space of dark matter (DM) halos in the AURIGA suite of cosmological hydrodynamics simulations of Milky Way analogues. We characterise halos by their spherical action distribution, a function of the specific…

We use Gaia DR2 systemic proper motions of 45 satellite galaxies to constrain the mass of the Milky Way using the scale free mass estimator of Watkins et al. (2010). We first determine the anisotropy parameter $\beta$, and the tracer…

We have applied our method for weighing the Galactic disk using phase-space spirals to the Gaia EDR3 proper motion sample. For stars in distant regions of the Galactic disk, the latitudinal proper motion has a close projection with vertical…

We present an approach to measure the Milky Way (MW) potential using the angular accelerations of stars in aggregate as measured by astrometric surveys like Gaia. Accelerations directly probe the gradient of the MW potential, as opposed to…

Several long, dynamically cold stellar streams have been observed around the Milky Way Galaxy, presumably formed from the tidal disruption of globular clusters. In integrable potentials---where all orbits are regular---tidal debris…

AIMS. We calculate the stellar density using star counts obtained from Gaia DR2 up to a Galactocentric distance R=20 kpc with a deconvolution technique for the parallax errors. Then we analyse the density in order to study the structure of…

We infer the gravitational potential of the Galactic disk by analysing the phase-space densities of 120 stellar samples in 40 spatially separate sub-regions of the solar neighbourhood, using Gaia's second data release (DR2), in order to…

We use Gaia photometry and astrometry to estimate the vertical spatial structure of the Milky Way at the Solar radius, formally accounting for sample incompleteness (the selection function) and parallax measurement uncertainty. Our results…

We use stellar kinematics from the latest Gaia data release (DR2) to measure the local dark matter density $\rho_{\rm DM}$ in a heliocentric cylinder of radius $R= 150 \ {\rm pc}$ and half-height $z= 200 \ {\rm pc}$. We also explore the…

The spherical Jeans equation is commonly used to infer dark matter distributions in dwarf spheroidal satellites of the Milky Way to constrain the nature of dark matter. One of its assumptions is that of dynamical equilibrium while the…

Intermediate mass stars and stellar remnants often host planets, and these dynamical systems evolve because of mass loss and tides. This paper considers the combined action of stellar mass loss and tidal dissipation on planetary orbits in…

Infinitesimal volumes stretch and contract as they coevolve with classical phase space trajectories according to linearized dynamics. Unless these tangent-space dynamics are modified, chaotic evolution causes the volume spanned by evolving…