Did Sgr cause the vertical waves in the solar neighbourhood?

  title={Did Sgr cause the vertical waves in the solar neighbourhood?},
  author={Morgan Bennett and Jo Bovy},
  journal={arXiv: Astrophysics of Galaxies},
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 release 2, determining the origin of this perturbation has become even more urgent. We develop and test a fast method for calculating the perturbation from a passing satellite on the vertical component of a part of a disc galaxy. This fast method allows us to… 

A Comprehensive Perturbative Formalism for Phase Mixing in Perturbed Disks. I. Phase Spirals in an Infinite, Isothermal Slab

Galactic disks are highly responsive systems that often undergo external perturbations and subsequent collisionless equilibration, predominantly via phase mixing. We use linear perturbation theory to

Exploring the Sgr–Milky Way–disk Interaction Using High-resolution N-body Simulations

The ongoing merger of the Sagittarius (Sgr) dwarf galaxy with the Milky Way is believed to strongly affect the dynamics of the Milky Way’s disk. We present a suite of 13 N-body simulations, with 500

Two-point Correlation Function Studies for the Milky Way: Discovery of Spatial Clustering from Disk Excitations and Substructure

We introduce a two-particle correlation function (2PCF) for the Milky Way, constructed to probe spatial correlations in the orthogonal directions of the stellar disk in the Galactic cylindrical

Characterizing the 3D Kinematics of Young Stars in the Radcliffe Wave

We present an analysis of the kinematics of the Radcliffe Wave, a 2.7 kpc long sinusoidal band of molecular clouds in the solar neighborhood recently detected via 3D dust mapping. With Gaia DR2

Snails across Scales: Local and Global Phase-mixing Structures as Probes of the Past and Future Milky Way

Signatures of vertical disequilibrium have been observed across the Milky Way’s (MW’s) disk. These signatures manifest locally as unmixed phase spirals in z–v z space (“snails-in-phase”), and

Arm Tangents and the Spiral Structure of the Milky Way—The Age Gradient

  • J. Vallée
  • Physics
    International Journal of Astronomy and Astrophysics
  • 2021
From the Sun, a look at the edge of each spiral arm in our Milky Way (seen tangentially, along the line of sight) can yield numerous insights. Using different arm tracers (dust, masers, synchrotron

Resolving local and global kinematic signatures of satellite mergers with billion particle simulations

In this work, we present two new ∼109 particle self-consistent simulations of the merger of a Sagittarius-like dwarf galaxy with a Milky Way (MW)-like disc galaxy. One model is a violent merger

Inferring time-dependent distribution functions from kinematic snapshots

We propose a method for constructing the time-dependent phase space distribution function (DF) of a collisionless system from an isolated kinematic snapshot. In general, the problem of mapping a



Vertical density waves in the Milky Way disc induced by the Sagittarius dwarf galaxy

Recently, Widrow and collaborators announced the discovery of vertical density waves in the Milky Way disk. Here we investigate a scenario where these waves were induced by the Sagittarius dwarf

Kinematics with Gaia DR2: the force of a dwarf

We use Gaia DR2 astrometric and line-of-sight velocity information combined with two sets of distances obtained with a Bayesian inference method to study the 3D velocity distribution in the Milky

Footprints of the Sagittarius dwarf galaxy in the Gaia data set

We analyse an N-body simulation of the interaction of the Milky Way (MW) with a Sagittarius-like dSph (Sgr), looking for signatures which may be attributed to its orbital history in the phase space

The vertical effects of disc non-axisymmetries from perturbation theory: the case of the Galactic bar

Evidence for non-zero mean stellar velocities in the direction perpendicular to the Galactic plane has been accumulating from various recent large spectroscopic surveys. Previous analytical and

The influence of Sagittarius and the Large Magellanic Cloud on the stellar disc of the Milky Way Galaxy

We present N-body simulations of a Sagittarius-like dwarf spheroidal galaxy (Sgr) that follow its orbit about the Milky Way (MW) since its first crossing of the Galaxy's virial radius to the present


We present evidence for a Galactic North–South asymmetry in the number density and bulk velocity of solar neighborhood stars. The number density profile, which is derived from main-sequence stars in

The last breath of the Sagittarius dSph

We use the astrometric and photometric data from Gaia Data Release 2 and line-of-sight velocities from various other surveys to study the 3d structure and kinematics of the Sagittarius dwarf galaxy.

The origin of the Gaia phase-plane spiral

A simple model is presented of the formation of the spiral the (z,v_z) phase plane of solar-neighbourhood stars that was recently discovered in Gaia data. The key is that the frequency Omega_z at

Milky Way mass models for orbit calculations

Studying the trajectories of objects like stars, globular clusters or satellite galaxies in the Milky Way allows to trace the dark matter halo but requires reliable models of its gravitational

Vertical waves in the solar neighbourhood inGaiaDR2

The vertical structure and dynamics of stars in our local Galactic neighbourhood contains much information about the local distribution of visible and dark matter and of perturbations to the Milky