text: 215,169,1184379591047163904,89709541,Anke Arentsen,"I am proud to present: the first Pristine Inner Galaxy Survey (PIGS) paper! <LINK> 🎉 In it, we study the kinematics of metal-poor stars in the Galactic bulge region. A summary follows: [1/7] <LINK> We used the anti-metal detector powers of CaHK photometry obtained at @CFHTelescope to find rare metal-poor stars in the metal-rich needle stack that is the Galactic bulge. [2/7] The kinematics of the metal-poor ([Fe/H] &lt; -1) component of the bulge hasn't really been studied in detail yet. We use a sample of thousands of stars observed with AAT/AAOmega+2dF to look at how this old component behaves! [3/7] We find that the rotation of stars in the inner Galaxy decreases with decreasing metallicity, until it completely disappears for the most metal-poor stars ([Fe/H] &lt; -2), see this figure (the line is a bar model): [4/7] <LINK> We also found a strikingly strong and continuous relation between the velocity dispersion (how hot the population is) and the metallicity: [5/7] <LINK> We propose a few interpretations: a density transition of components of different kinematics & metallicities, a different mapping of stars onto the boxy/peanut bulge and/or the influence of the bar on a pressure-supported component. Probably all of them play a role! [6/7] So this is clearly not the last PIGS paper, since a lot is still unknown about this exciting population of stars..! :) [7/7]  (with Twitter people @nfmartin1980, @Nico_Longeard, @kmalhan07, @Astro_Sestitof, @Thomas_gft, @Cosmic_Horizons and @FadAstra) @nfmartin1980 @CFHTelescope I guess I shouldn’t have put that - there... but yes, this paper is secretly about how we detected anti-matter in metal-poor stars! Should have submitted to Nature... @arm2armtweet Do you recognise the giraffe plot?!",http://arxiv.org/abs/1910.06337,"Our Galaxy is known to contain a central boxy/peanut-shaped bulge, yet the importance of a classical, pressure-supported component within the central part of the Milky Way is still being debated. It should be most visible at low metallicity, a regime that has not yet been studied in detail. Using metallicity-sensitive narrow-band photometry, the Pristine Inner Galaxy Survey (PIGS) has collected a large sample of metal-poor ([Fe/H] < -1.0) stars in the inner Galaxy to address this open question. We use PIGS to trace the metal-poor inner Galaxy kinematics as function of metallicity for the first time. We find that the rotational signal decreases with decreasing [Fe/H], until it becomes negligible for the most metal-poor stars. Additionally, the velocity dispersion increases with decreasing metallicity for -3.0 < [Fe/H] < -0.5, with a gradient of -44 $\pm$ 4 km$\,$s$^{-1}\,$dex$^{-1}$. These observations may signal a transition between Galactic components of different metallicities and kinematics, a different mapping onto the boxy/peanut-shaped bulge for former disk stars of different metallicities and/or the secular dynamical and gravitational influence of the bar on the pressure-supported component. Our results provide strong constraints on models that attempt to explain the properties of the inner Galaxy. ","The Pristine Inner Galaxy Survey (PIGS) I: Tracing the kinematics of