Revisit NGC 5466 Tidal Stream with $Gaia$, SDSS/SEGUE and LAMOST

TL;DR

This study identifies 11 stars in the NGC 5466 tidal stream using Gaia, SDSS, and LAMOST data, suggesting the stream is longer and possibly perturbed by the LMC, with implications for understanding the Milky Way's gravitational field.

Contribution

The paper presents the first identification of 11 member stars of the NGC 5466 tidal stream, including 7 new detections, and demonstrates the stream's potential as a probe of the Galactic potential.

Findings

11 stream members identified, 7 are new

Stream extends to 60 degrees, longer than previous estimates

Evidence suggests LMC perturbation of the stream

Abstract

By mining the data from $Gaia$ EDR3, SDSS/SEGUE DR16 and LAMOST DR8, 11 member stars of the NGC 5466 tidal stream are detected and 7 of them are newly identified. To reject contaminators, a variety of cuts are applied in sky position, color-magnitude diagram, metallicity, proper motion and radial velocity. We compare our data to a mock stream generated by modeling the cluster's disruption under a smooth Galactic potential plus the Large Magellanic Cloud (LMC). The concordant trends in phase-space between the model and observations imply that the stream might have been perturbed by LMC. The two most distant stars among 11 detected members trace the stream's length to $60^\circ$ of sky, supporting and extending the previous length of $45^\circ$. Given that NGC 5466 is so distant and potentially has a longer tail than previously thought, we expect that NGC 5466 tidal stream could be a useful tool in constraining the Milky Way gravitational field.