Detection of Strong Epicyclic Density Spikes in the GD-1 Stellar Stream. An Absence of Evidence for the Influence of Dark Matter Subhalos?

Abstract

The density variations in thin stellar streams may encode important information on the nature of the dark matter. For instance, if dark matter aggregates into massive sub-halos, these perturbers are expected to scatter stars out of dynamically cold stellar streams, possibly leading to detectable gaps in those structures. Here we re-examine the density variations in the GD-1 stream, using Gaia DR2 astrometry, Pan-STARRS photometry, together with high precision radial velocities measured with the CFHT/ESPaDOnS and VLT/UVES instruments and complemented with public radial velocity catalogs. We show that after correcting for projection effects, the density profile exhibits high contrast periodic peaks, separated by $2.64\pm 0.18$ kpc. An N-body simulation is presented that reproduces this striking morphology with simple epicyclic motion in a smooth Galactic potential. We also discuss the reliability of measuring density variations using ground-based photometric surveys, and for the particular case of GD-1 we highlight some of the artifacts present in the Gaia DR2 catalog along its track. Massive dark subhalos do not appear to be required to explain the density clumping along GD-1.

arXiv comment18 pages, 14 figures, accepted for publication in ApJ (some typos fixed)

References in corpus (42)

• A Universal Density Profile from Hierarchical Clustering
• Gaia Data Release 2. Summary of the contents and survey properties
• PARSEC: stellar tracks and isochrones with the PAdova and TRieste Stellar Evolution Code
• Gaia Data Release 2: The astrometric solution
• The Aquarius Project: the subhalos of galactic halos
• The Apache Point Observatory Galactic Evolution Experiment (APOGEE)
• SEGUE: A Spectroscopic Survey of 240,000 stars with g=14-20
• Detection of the gravitational redshift in the orbit of the star S2 near the Galactic centre massive black hole
• The Pan-STARRS1 Surveys
• Constraining the Milky Way potential with a 6-D phase-space map of the GD-1 stellar stream
• The Haunted Halos of Andromeda and Triangulum: A panorama of galaxy formation in action
• The Circular Velocity Curve of the Milky Way from $5$ to $25$ kpc
• Mass models of the Milky Way
• The Milky Way total mass profile as inferred from Gaia DR2
• Detection of a 63 Degree Cold Stellar Stream in the Sloan Digital Sky Survey
• Uncovering CDM halo substructure with tidal streams
• A Very Fast and Momentum-Conserving Tree Code
• How Lumpy is the Milky Way's Dark Matter Halo?
• The Spur and the Gap in GD-1: Dynamical evidence for a dark substructure in the Milky Way halo
• Ghostly Tributaries to the Milky Way: Charting the Halo's Stellar Streams with the Gaia DR2 catalogue
• SHARP -- VII. New constraints on the dark matter free-streaming properties and substructure abundance from gravitationally lensed quasars
• The Streams of the Gaping Abyss: A population of entangled stellar streams surrounding the Inner Galaxy
• More on the structure of tidal tails
• Dark Matter Sub-Halo Counts via Star Stream Crossings
• On the structure of tidal tails
• Constraining the Milky Way Halo Potential with the GD-1 stellar stream
• Off the beaten path: Gaia reveals GD-1 stars outside of the main stream
• STREAMFINDER I: A New Algorithm for detecting Stellar Streams
• Low-mass halo perturbations in strong gravitational lenses at redshift z$\sim$0.5 are consistent with CDM
• Generation of mock tidal streams
• Tidal debris of dwarf spheroidals as a probe of structure formation models
• The Canada-France Imaging Survey: First results from the u-band component
• Gaps in globular cluster streams: giant molecular clouds can cause them too
• Stellar Streams as Probes of Dark Halo Mass and Morphology: A Bayesian Reconstruction
• Gaps in the GD-1 Star Stream
• An Orbit Fit for the Grillmair Dionatos Cold Stellar Stream
• Butterfly in a Cocoon, Understanding the origin and morphology of Globular Cluster Streams: The case of GD-1
• A closer look at the spur, blob, wiggle, and gaps in GD-1
• A deeper look at the GD1 stream: density variations and wiggles
• Searching for the GD-1 Stream Progenitor in Gaia DR2 with Direct N-body Simulations
• Modeling GD-1 Gaps in a Milky-Way Potential
• STREAMFINDER II: A possible fanning structure parallel to the GD-1 stream in Pan-STARRS1

Cited by in corpus (34)

• Ultra-Light Dark Matter
• Wave Dark Matter
• Charting the Galactic acceleration field I. A search for stellar streams with Gaia DR2 and EDR3 with follow-up from ESPaDOnS and UVES
• The Subhalo Mass Function and Ultralight Bosonic Dark Matter
• Evidence of a population of dark subhalos from Gaia and Pan-STARRS observations of the GD-1 stream
• Preparing for low surface brightness science with the Vera C. Rubin Observatory: characterisation of tidal features from mock images
• Broken into Pieces: ATLAS and Aliqa Uma as One Single Stream
• Probing the nature of dark matter with accreted globular cluster streams
• Microarcsecond Astrometry: Science Highlights from Gaia
• Asymmetrical tidal tails of open star clusters: stars crossing their cluster's prah challenge Newtonian gravitation
• The Pristine survey -- XVI. The metallicity of 26 stellar streams around the Milky Way detected with the STREAMFINDER in Gaia EDR3
• The hidden past of M92: Detection and characterization of a newly formed 17° long stellar stream using the Canada-France Imaging Survey
• Velocity Dispersion of the GD-1 Stellar Stream
• The e-TidalGCs Project: Modeling the extra-tidal features generated by Galactic globular clusters
• A chemo-dynamical link between the Gjöll stream and NGC 3201
• Astrophysical Tests of Dark Matter Self-Interactions
• Milky Way archaeology using RR Lyrae and type II Cepheids I. The Orphan stream in 7D using RR Lyrae stars
• Evolution of subhalo orbits in a smoothly-growing host halo potential
• GD-1 Stellar Stream and Cocoon in the DESI Early Data Release
• Probability of forming gaps in the GD-1 stream by close encounters of globular clusters
• Sensitivity of the Cherenkov Telescope Array to dark subhalos
• A giant thin stellar stream in the Coma Galaxy Cluster
• Variation in the Stellar Mass Function Along Stellar Streams
• Hidden deep in the halo: selection of a reduced proper motion halo catalogue and mining retrograde streams in the velocity space
• Stellar streams and dark substructure: the diffusion regime
• Time evolution of gaps in stellar streams in axisymmetric Stäckel potentials
• Anticipating the XRISM search for the decay of resonantly produced sterile neutrino dark matter
• Dark Matter Freeze-In and Small-Scale Observables: Novel Mass Bounds and Viable Particle Candidates
• Modelling the Track of the GD-1 Stellar Stream Inside a Host with a Fermionic Dark Matter Core-Halo Distribution
• The Pristine survey: XXVII. The extremely metal-poor stream C-19 stretches over more than 100 degrees
• Inferring the density and membership of stellar streams with flexible models: The GD-1 stream in Gaia Data Release 3
• An analytic description of substructure-induced gravitational perturbations in stellar systems
• No Stream Left Unscathed: The imprint of a host galaxy
• Epicyclic Density Variations in the Indus Stellar Stream