부산대학교 도서관

We construct the Schwarzschild dynamical models for 11 early-type galaxies with the SAURON and Mitchell stellar IFUs out to 2–4 R e, and construct dynamical models with combined stellar and H i kinematics for a subsample of four galaxies with H i velocity fields out to 10 R e obtained from the Westerbork Synthesis Radio Telescope, thus robustly obtaining the dark matter content out to large radii for these galaxies. Adopting a generalized-NFW dark matter profile, we measure an NFW-like density cusp in the dark matter inner slopes for all sample galaxies, with a mean value of 1.00 ± 0.04 (rms scatter 0.15). The mean dark matter fraction for the sample is 0.2 within 1 R e, and increases to 0.4 at 2 R e, and 0.6 at 5 R e. The dark matter fractions within 1 R e of these galaxies are systematically lower than the predictions of both the TNG-100 and EAGLE simulations. For the dark matter fractions within 2 R e and 5 R e, 40 and 70 per cent galaxies are 1σ consistent with either the TNG-100 or the EAGLE predictions, while the remaining 60 and 30 per cent galaxies lie below the 1σ region. Combined with 36 galaxies with dark matter fractions measured out to 5 R e in the literature, about 10 per cent of these 47 galaxies lie below the 3σ region of the TNG-100 or EAGLE predictions. [ABSTRACT FROM AUTHOR]