Joint Survey Processing

Figure from S. Fajardo-Acosta et al. which shows the Toomre diagram of 10,818 stars with Subaru SuprimeCam colors -1.25 < r - i+ < 3.75 and SExtractor F814W AB magnitude in the range 19 to 25. The dashed lines represent total galactic space velocities of 220 km/s and 85 km/s, to delimit the loci of the halo, the thick and thin disks respectively. The large filled circles denote initial estimates of the space velocities of two stars, assuming solar metallicity giant star absolute magnitudes, that we estimate to be in the halo. The blue solid lines are re-derived space velocities of these two stars assuming metal-poor giant star absolute magnitudes, for consistency with the halo, and also using Monte Carlo simulations in view of large parallax uncertainties, yielding distance and corresponding velocity ranges for each star.