The impact of a massive Sagittarius dSph on GD-1-like streams

Abstract

We investigate the effects of a massive ($\gtrsim 4\times 10^{10}{M}_{\odot }$) Sagittarius dwarf spheroidal galaxy (Sgr) on stellar streams using test particle simulations in a realistic Milky Way potential. We find that Sgr can easily disrupt streams formed more than $\sim 3$ Gyr ago, while stars stripped more recently are generally unaffected. In certain realizations, Sgr is able to produce asymmetry between the leading and trailing tails of Pal 5, qualitatively similar to observations. Using data from the Gaia space telescope and elsewhere, we fit models to the GD-1 stream in the presence of a Sgr with various initial masses. While the best-fitting models do show perturbations resulting from interactions with Sgr, we find that the level of disruption is not significantly greater than in the observed stream. To investigate the general effects of Sgr on a population of streams, we generate 1000 mock streams on GD-1-like orbits with randomized orientations. Some streams show clear evidence of disruption, becoming folded on the sky or developing asymmetry betweeen their two tails. However, many survive unaffected and the peak surface brightness of stars is decreased by no more than $\sim 0.3$ mag/arcsec${}^2$ on average. We conclude that Sgr having an initial mass of $\gtrsim 4\times 10^{10}{M}_{\odot }$ is compatible with the survival and detection of streams formed more than 3 Gyr ago.

19 pages, 12 figures, published in MNRAS. Animated figures can be found at https://www.youtube.com/playlist?list=PLEleLLhXAwEMx6GcSror-iF-QsskHrXYM

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Cited by in corpus (13)

• $S^5$: Probing the Milky Way and Magellanic Clouds potentials with the 6-D map of the Orphan-Chenab stream
• The effect of the LMC on the Milky Way system
• Mapping Dark Matter with Extragalactic Stellar Streams: the Case of Centaurus A
• The dark side of FIRE: predicting the population of dark matter subhaloes around Milky Way-mass galaxies
• GD-1 Stellar Stream and Cocoon in the DESI Early Data Release
• Ironing the folds: The phase space chevrons of a GSE-like merger as a dark matter subhalo detector
• Characterization and dynamics of the peculiar stream Jhelum, A tentative role for the Sagittarius dwarf galaxy
• Bar-driven dispersal of Galactic substructure
• Trojan globular clusters: radial migration via trapping in bar resonances
• Measurement of Substructure from the Kinematics of the GD-1 Stellar Stream
• Stellar halo striations from assumptions of axisymmetry
• Constraining the population of dark matter halo shapes using hierarchical inference with extragalactic stellar streams
• No Stream Left Unscathed: The imprint of a host galaxy