Properties of the lower segment of M31's North West stream.

We present a kinematic and spectroscopic analysis of 40 red giant branch stars, in 9 fields, exquisitely delineating the lower segment of the North West stream (NW-K2), which extends for |$\sim$| 80 kpc from the centre of the Andromeda galaxy. We measure the stream's systemic velocity as −439.3 |$^{+4.1}_{-3.8}$| km s |$^{-1}$| with a velocity dispersion =16.4 |$^{+5.6}_{-3.8}$| km s |$^{-1}$| that is in keeping with its progenitor being a dwarf galaxy. We find no detectable velocity gradient along the stream. We determine |$-1.3\pm0.1$| |$\le$| |$\langle[\mathrm{ Fe/H}]_{\rm spec}\rangle$| |$\le$| |$-1.2\pm0.8$| but find no metallicity gradient along the stream. We are able to plausibly associate NW-K2 with the globular clusters PAndAS-04, PAndAS-09, PAndAS-10, PAndAS-11, and PAndAS-12 but not with PAndAS-13 or PAndAS-15, which we find to be superimposed on the stream but not kinematically associated with it. [ABSTRACT FROM AUTHOR]