SIMBAD references

We present new FLAMES+GIRAFFE spectroscopy of 36 member stars in the isolated Local Group dwarf spheroidal galaxy Tucana. We measure a systemic velocity for the system of v_Tuc = 216.7_–2.8^+2.9 km s^–1, and a velocity dispersion of σ_v,Tuc = 14.4_–2.3^+2.8 km s^–1. We also detect a rotation gradient of d/v_r dχ= 7.6^+4.2_–4.3 km s^–1 kpc^–1, which reduces the systemic velocity to v_Tuc = 215.2_–2.7^+2.8 km s^–1 and the velocity dispersion to σ_v,Tuc = 13.3_–2.3^+2.7 km s^–1. We perform Jeans modelling of the density profile of Tucana, using the line-of-sight velocities of the member stars. We find that it favours a high central density consistent with 'pristine' subhaloes in Λ cold dark matter, and a massive dark matter halo (∼10¹⁰ M_☉) consistent with expectations from abundance matching. Tucana appears to be significantly more centrally dense than other isolated Local Group dwarfs, making it an ideal laboratory for testing dark matter models.