Galactoseismology and the Local Density of Dark Matter

Abstract

We model vertical breathing mode perturbations in the Milky Way's stellar disc and study their effects on estimates of the local dark matter density, surface density, and vertical force. Evidence for these perturbations, which involve compression and expansion of the Galactic disc perpendicular to its midplane, come from the SEGUE, RAVE, and LAMOST surveys. We show that their existence may lead to systematic errors of $10\%$ or greater in the vertical force $K_z(z)$ at $|z|=1.1\mathrm{kpc}$. These errors translate to $\gtrsim 25\%$ errors in estimates of the local dark matter density. Using different mono-abundant subpopulations as tracers offers a way out: if the inferences from all tracers in the Gaia era agree, then the dark matter determination will be robust. Disagreement in the inferences from different tracers will signal the breakdown of the unperturbed model and perhaps provide the means for determining the nature of the perturbation.

9 pages, 11 figures, submitted to MNRAS, minor typos corrected, references added and conclusion improved

References in corpus (6)

• The Local Dark Matter Density
• On the local dark matter density
• A new determination of the local dark matter density from the kinematics of K dwarfs
• Bending and Breathing Modes of the Galactic Disk
• Radial and vertical flows induced by galactic spiral arms: likely contributors to our "wobbly Galaxy''
• The Vertical Structure and Kinematics of Grand Design Spirals

Cited by in corpus (16)

• The Canada-France Imaging Survey: First results from the u-band component
• Implications of a time-varying Galactic potential for determinations of the dynamical surface density
• Spontaneous generation of bending waves in isolated Milky Way-like discs
• The Stellar Distribution Function and Local Vertical Potential from Gaia DR2
• Milky Way Tomography with K and M Dwarf Stars: the Vertical Structure of the Galactic Disk
• Weighing the Galactic disk in sub-regions of the solar neighbourhood using Gaia DR2
• Charting Galactic Accelerations: When and How to Extract a Unique Potential from the Distribution Function
• Estimating the local dark matter density in a non-axisymmetric wobbling disc
• The Milky Way, Coming into Focus: Precision Astrometry Probes its Evolution, and its Dark Matter
• The North/South Asymmetry of the Galaxy: Possible Connection to the Vertical Phase Space Snail
• Residuals of an Equilibrium Model for the Galaxy Reveal a State of Disequilibrium in the Solar Neighborhood
• A method to calculate the local density distribution of the Galaxy from the Tycho-Gaia Astrometric Solution data
• Non-equilibrium in the Solar Neighbourhood using dynamical modelling with Gaia DR2
• Exploring the centre of mass properties of LG-like galaxies
• Charting galactic accelerations II: how to 'learn' accelerations in the solar neighbourhood
• Comparing dark matter and MOND hyphotheses from the distribution function of A, F, early-G stars in the solar neighbourhood