The Pristine survey -- XVI. The metallicity of 26 stellar streams around
  the Milky Way detected with the STREAMFINDER in Gaia EDR3
  We use the photometric metallicities provided by the panoramic Pristine
survey to study the veracity and derive the metallicities of the numerous
stellar streams found by Ibata et al. (2021) from the application of the
STREAMFINDER algorithm to the Gaia EDR3 data. All 26 streams present in
Pristine show a clear metallicity distribution function, which provides an
independent check of the reality of these structures, supporting the
reliability of STREAMFINDER in finding streams and the power of Pristine to
measure precise metallicities. We further present 6 candidate structures with
coherent phase-space and metallicity signals that are very likely streams. The
majority of studied streams are very metal-poor (14 structures with
[Fe/H]<-2.0) and include 3 extremely metal-poor systems ([Fe/H]<-3.0; C-11,
C-19, and C-20). These streams could be the closest debris of low-luminosity
dwarf galaxies or may have originated from globular clusters of significantly
lower metallicity than any known current Milky Way globular cluster. Our study
shows that the promise of the Gaia data for Galactic Archeology studies can be
substantially strengthened by quality photometric metallicities, allowing us to
peer back into the earliest epochs of the formation of our Galaxy and its
stellar halo constituents.
