相关论文: Dark Galactic subhalos and the Gaia snail
The Gaia snail is a spiral feature in the distribution of solar-neighbourhood stars in position and velocity normal to the Galactic midplane. The snail probably arises from phase mixing of gravitational disturbances that perturbed the disc…
We utilize a novel numerical technique to model star formation in cosmological simulations of galaxy formation - called Superstars - to simulate a Milky Way-like galaxy with $\gtrsim10^8$ star particles to study the formation and evolution…
Gaia has revealed a variety of substructures in the phase space of stars in the Solar neighborhood, including the vertical `Snail' in $(z,v_z)$ space. Such substructures are often interpreted as the incompletely phase-mixed response of the…
The phase spiral is a perturbation to the vertical phase-space distribution of stars in the Milky Way disk. We study the phase spiral's properties and how they vary with spatial position, in order to constrain its origin and evolution, as…
Galaxies are not in a dynamical steady state. They continually undergo perturbations, e.g., from infalling dwarf galaxies and dark-matter substructure. After a dynamical perturbation, stars phase mix towards a new steady state; in so doing…
The hierarchical structure formation model predicts that stellar halos should form, at least partly, via mergers. If this was a predominant formation channel for the Milky Way's halo, imprints of this merger history in the form of moving…
In hierarchical structure formation, dark matter halos that merge with larger halos can persist as subhalos. These subhalos are likely hosts of visible galaxies. While the dense halo environment rapidly strips subhalos of their dark mass,…
The distribution of stars in the Milky Way disc shows a spiral structure--the Snail--in the space of velocity and position normal to the Galactic mid-plane. The Snail appears as straight lines in the vertical frequency--vertical phase plane…
The vertical distribution of stars in the solar neighbourhood is not in equilibrium but contains a wave signature in both density and velocity space originating from a perturbation. With the discovery of the phase-space spiral in Gaia data…
{\it Gaia} Data Release 2 (DR2) revealed that the Milky Way contains significant indications of departures from equilibrium in the form of asymmetric features in the phase space density of stars in the Solar neighborhood. One such feature…
The Galaxy is found to be in disequilibrium based on recent findings of the North/South (N/S) asymmetry and the phase mixing signatures, such as a phase spiral (snail) structure in the vertical phase space ($z-V_{z}$). We show that the N/S…
The hierarchical model of galaxy formation predicts that the Milky Way halo is populated by tidal debris of dwarf galaxies and globular clusters. Due to long dynamical times, debris from the lowest mass objects remains coherent as thin and…
Using a single N-body simulation ($N=0.14\times 10^9$) we explore the formation, evolution and spatial variation of the phase-space spirals similar to those recently discovered by Antoja et al. in the Milky Way disk, with Gaia DR2. For the…
We propose a novel method utilizing stellar kinematic data to detect low-mass substructure in the Milky Way's dark matter halo. By probing characteristic wakes that a passing dark matter subhalo leaves in the phase space distribution of…
We provide a set of numerical N-body simulations for studying the formation of the outer Milky Ways's stellar halo through accretion events. After simulating minor mergers of prograde and retrograde orbiting satellite halo with a Dark…
In 2018, the ESA \Gaia\ satellite discovered a remarkable spiral pattern ("phase spiral") in the $z-V_z$ phase plane throughout the solar neighbourhood, where $z$ and $V_z$ are the displacement and velocity of a star perpendicular to the…
The Via Lactea simulation of the dark matter halo of the Milky Way predicts the existence of many thousands of bound subhalos distributed approximately with equal mass per decade of mass. Here we show that: a) a similar steeply rising…
We study the formation histories and present-day structure of satellite galaxies formed in a high resolution hydrodynamic simulation of a Milky Way-like galaxy. The simulated satellites span nearly 4 orders of magnitude in luminosity but…
The second data release of ESA's $Gaia$ mission revealed numerous signatures of disequilibrium in the Milky Way's disc. These signatures are seen in the planar kinematics of stars, which manifest as ridges and ripples in $R-v_{\phi}$, and…
We explore the properties of Milky Way subhalos in self-interacting dark matter models for moderate cross sections of 1 to 5 cm$^2$g$^{-1}$ using high-resolution zoom-in N-body simulations. We include the gravitational potential of a…