The Pristine survey XIII: uncovering the very metal-poor tail of the thin disc

ABSTRACT We evaluate the rotational velocity of stars observed by Pristine survey towards Galactic anticentre spanning a wide range metallicities from extremely metal-poor regime ([Fe/H] < ?3) to nearly solar metallicity. In direction, (V?) is similar tangential in galactic longitude direction (V?). This allows us estimate V? Gaia early data release 3 (Gaia EDR3) proper motions for without radial measurements. substantially increases sample outer disc with estimated velocities. Our stellar dominated kinematical thin mean rotation ??220 km s?1. However, our analysis reveals presence more substructures. The most intriguing well-populated extension down [Fe/H] ? ?2 . A scarcer fast-rotating population reaching ?3.5 also detected but statistical significance unambiguously state whether this or high-rotating tail hotter structures (like thick halo). addition, slowly rotating component required explain V? distribution at > ?1.5 Furthermore, we detect signatures ‘heated disc’, so-called Splash, higher than ??1.5. Finally, halo net prograde motion.