Building an Acceleration Ladder with Tidal Streams and Pulsar Timing

Abstract

We analyze stellar streams in action-angle coordinates combined with recent local direct acceleration measurements to provide joint constraints on the potential of our Galaxy. Our stream analysis uses the Kullback-Leibler divergence with a likelihood analysis based on the two-point correlation function. We provide joint constraints from pulsar accelerations and stellar streams for local and global parameters that describe the potential of the Milky Way (MW). Our goal is to build an ``acceleration ladder", where direct acceleration measurements that are currently limited in dynamic range are combined with indirect techniques that can access a much larger volume of the MW. To constrain the MW potential with stellar streams, we consider the Palomar 5, Orphan, Nyx, Helmi and GD1 streams. Of the potential models that we have considered here, the preferred potential for the streams is a two-component Staeckel potential. We also compare the vertical accelerations from stellar streams and pulsar timing, defining a function $f(z)={\alpha }_{1pulsar}z-\frac{\partial \Phi }{\partial z}$, where $\Phi$ is the MW potential determined from stellar streams, and ${\alpha }_{1\mathrm{pulsar}}z$ is the vertical acceleration determined from pulsar timing observations. Our analysis indicates that the Oort limit determined from streams is consistently (regardless of the choice of potential) lower than that determined from pulsar timing observations. The calibration we have derived here may be used to correct the estimate of the acceleration from stellar streams.

arXiv comment8 pages, 4 figures, 1 table. Accepted by ApJ Letters

References in corpus (43)

• SciPy 1.0--Fundamental Algorithms for Scientific Computing in Python
• Gaia Data Release 2. Summary of the contents and survey properties
• The Gaia mission
• galpy: A Python Library for Galactic Dynamics
• The Ghost of Sagittarius and Lumps in the Halo of the Milky Way
• Debris streams in the solar neighbourhood as relicts from the formation of the Milky Way
• Constraining the Milky Way potential with a 6-D phase-space map of the GD-1 stellar stream
• Tango for three: Sagittarius, LMC, and the Milky Way
• The Spiral Structure of the Outer Milky Way in Hydrogen
• Tidal Streams as Probes of the Galactic Potential
• The Spur and the Gap in GD-1: Dynamical evidence for a dark substructure in the Milky Way halo
• A sharper view of Pal 5's tails: Discovery of stream perturbations with a novel non-parametric technique
• Constraining the Milky Way Halo Potential with the GD-1 stellar stream
• The Orbit of the Orphan Stream
• A Magellanic Origin for the Warp of the Galaxy
• Dynamical modeling of tidal streams
• Generation of mock tidal streams
• Stream-orbit misalignment I: The dangers of orbit-fitting
• The information content in cold stellar streams
• The Pal 5 Star Stream Gaps
• Milky Way Mass and Potential Recovery Using Tidal Streams in a Realistic Halo
• Stellar Streams as Probes of Dark Halo Mass and Morphology: A Bayesian Reconstruction
• Gaps in the GD-1 Star Stream
• Effects of baryonic and dark matter substructure on the Pal 5 stream
• Dynamics of stream-subhalo interactions
• Action-space clustering of tidal streams to infer the Galactic potential
• Inferring the gravitational potential of the Milky Way with a few precisely measured stars
• High-resolution spectroscopy of the GD-1 stellar stream localizes the perturber near the orbital plane of Sagittarius
• The Role of Gas In Maintaining Quasi-Steady Spiral Structure In Stellar Disks
• A measurement of the Galactic plane mass density from binary pulsar accelerations
• Probabilistic model for constraining the Galactic potential using tidal streams
• Galactic potential constraints from clustering in action space of combined stellar stream data
• Modeling the gravitational potential of a cosmological dark matter halo with stellar streams
• Towards a direct measure of the Galactic acceleration
• Finding Dwarf Galaxies From Their Tidal Imprints
• Tidal Imprints of a Dark Sub-Halo on the Outskirts of the Milky Way II. Perturber Azimuth
• Eclipse timing the Milky Way's gravitational potential
• Spitzer, Gaia, and the Potential of the Milky Way
• Substructures, Resonances and debris streams
• Birth Sites of Young Stellar Associations and Recent Star Formation in a Flocculent Corrugated Disk
• The GALAH Survey: No chemical evidence of an extragalactic origin for the Nyx stream
• Gravitational Potential from small-scale clustering in action space: Application to Gaia DR2
• Orbital phase-driven biases in Galactic mass constraints from stellar streams

Cited by in corpus (1)

• Modelling the Track of the GD-1 Stellar Stream Inside a Host with a Fermionic Dark Matter Core-Halo Distribution