Orbital decomposition of CALIFA spiral galaxies

Schwarzschild orbit-based dynamical models are widely used to uncover the internal dynamics of early-type galaxies and globular clusters. Here we present for the first time the Schwarzschild models of late-type galaxies: an SBb galaxy NGC4210 and an S0 galaxy NGC6278 from the Calar Alto Legacy Integral Field Area (CALIFA) survey. The mass profiles within 2R(e) are constrained well with 1 sigma statistical error of similar to 10 per cent. The luminous and dark mass can be disentangled with uncertainties of similar to 20 and similar to 50 per cent, respectively. From Re to 2Re, the dark matter fraction increases from 14 +/- 10 to 18 +/- 10 per cent for NGC4210 and from 15 +/- 10 to 30 +/- 20 per cent for NGC6278. The velocity anisotropy profiles of both sigma(r)/sigma(t) and sigma(z)/sigma(R) are well constrained. The inferred internal orbital distributions reveal clear substructures. The orbits are naturally separated into three components: a cold component with near circular orbits; a hot component with near radial orbits and a warm component in between. The photometrically identified exponential discs are predominantly made up of cold orbits only beyond similar to 1R(e), while they are constructed mainly with the warm orbits inside. Our dynamical hot components are concentrated in the inner regions, similar to the photometrically identified bulges. The reliability of the results, especially the orbit distribution, is verified by applying the model to mock data.