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.

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

References in corpus (9)

• The Haunted Halos of Andromeda and Triangulum: A panorama of galaxy formation in action
• Detection of a 63 Degree Cold Stellar Stream in the Sloan Digital Sky Survey
• The Streams of the Gaping Abyss: A population of entangled stellar streams surrounding the Inner Galaxy
• On the structure of tidal tails
• Generation of mock tidal streams
• The Canada-France Imaging Survey: First results from the u-band component
• Gaps in globular cluster streams: giant molecular clouds can cause them too
• An Orbit Fit for the Grillmair Dionatos Cold Stellar Stream
• A closer look at the spur, blob, wiggle, and gaps in GD-1

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