相关论文: Weighing the Galactic disk using phase-space spira…
The properties of gravitational-wave (GW) propagation are modified in alternative theories of gravity and are crucial observables to test gravity at cosmological distance. The propagation speed has already been measured from GW170817 so…
The IMAGES project aims at measuring the velocity fields of a representative sample of 100 massive galaxies at z=0.4-0.75, selected in the CDFS, the CFRS and the HDFS fields. It uses the world-unique mode of multiple integral field units of…
We use a set of high-resolution N-body simulations of the Galactic disk to study its interactions with the population of satellites predicted cosmologically. One simulation illustrates that multiple passages of massive satellites with…
We have established the exact expression for the gravitational potential of a homogeneous polar cell - an elementary pattern used in hydrodynamical simulations of gravitating discs. This formula, which is a closed-form, works for any…
A method for recognizing the types of linear acoustic gravity waves (AGWs) in the atmosphere from satellite measurements is proposed. It is shown that the polarization relations between fluctuations of wave parameters (velocity, density,…
The detection of gravitational waves from binary black hole and neutron star mergers by ground-based interferometers, as well as the evidence for a gravitational wave background from pulsar timing array experiments, has marked a new era in…
Near-future data from ESA's Gaia mission will provide precise, full phase-space information for hundreds of millions of stars out to heliocentric distances of ~10 kpc. This "horizon" for full phase-space measurements is imposed by the Gaia…
Gravitational stability of a disc consisting of the gaseous and the stellar components are studied in the linear regime when the gaseous component is turbulent. A phenomenological approach is adopted to describe the turbulence, in which not…
Observations reveal that mature spiral galaxies consist of stars, gases and plasma approximately distributed in a thin disk of circular shape, usually with a central bulge. The rotation velocities quickly increase from the galactic center…
Most measurements of mass in Astronomy that use kinematics of stars or gas rely on assumptions of equilibrium that are often hard to verify. Instead, we develop a novel idea that uses the clustering in action space, as a probe of underlying…
An expression for rotational velocity of a test particle around the central mass in the invariant plane is derived. For this, a line element of Schwarzschild de-Sitter space-time is used to study the effect of cosmological constant…
The presence of a gravitational wave background (GWB) can be established not only via exquisitely precise pulsar timing array (PTA) measurements, but also via astrometric observations. Indeed, the very same background responsible for the…
Space provides unique opportunities to test gravitation. By using an interplanetary spacecraft as a test mass, it is possible to test General Relativity at the Solar System distance scale. This requires to compute accurately the trajectory…
Observational manifestations of disturbances in a protoplanetary disk caused by a collision with a massive planet are studied. It is assumed that the planet moves along a parabolic trajectory that intersects the disk plane near the star.…
In this paper, we present a holistic view of the detection, characterization, and origin of stellar streams in the disk of a simulated Milky Way-like galaxy. The star-by-star simulation of the Galaxy evolves stars born in clusters in a…
In this paper, we calculate simulated scattered light images of a circumstellar disk in which a planet is forming by gravitational instability. The simulated images bear no correlation to the vertically integrated surface density of the…
The 511 keV positron annihilation emission remains a mysterious component of the high energy emission of our Galaxy. Its study was one of the key scientific objective of the SPI spectrometer on-board the INTEGRAL satellite. In fact, a lot…
Using observational data, we build numerical N-body, hydrodynamical and combined equilibrium models for the spiral galaxy NGC 5247. The models turn out to be unstable towards spiral structure formation. We simulate scenarios of spiral…
In testing gravity a model-independent way, one of crucial tests is measuring the propagation speed of a gravitational wave (GW). In general relativity, a GW propagates with the speed of light, while in the alternative theories of gravity…
Using a new algorithm for estimating the actions of orbits a parametrised distribution function is automatically fitted to observational data for the solar neighbourhood. We adopt a gravitational potential that is generated by three discs…