  Based on a combined charge and vector spin transport theory capable of
imaging noncollinear magnetic textures on surfaces with spin-polarized scanning
tunneling microscopy (SP-STM), the high-resolution tunneling electron charge
and coupled spin transport properties of a variety of N\'eel- and Bloch-type
skyrmions are investigated. Axially symmetric skyrmions are considered within
the same topology class characterized by a vorticity value of $m=1$, and their
helicities are varied by taking $\gamma=0$ and $\pi$ values for the N\'eel
skyrmions and $\gamma=-\pi/2$ and $\pi/2$ values for the Bloch skyrmions.
Depending on the orientation of the magnetization of the STM tip as well as on
the helicity and the time-reversal of the skyrmionic spin structures, several
relationships between their spin transport vector components, the in-plane and
out-of-plane spin transfer torque and the longitudinal spin current, are
identified. The magnitudes of the spin transport vector quantities show close
relation to standard charge current SP-STM images. It is also demonstrated that
the SP-STM images can be used to determine the helicity of the skyrmions.
Moreover, the modified spin polarization vectors of the conduction electrons
due to the local chirality of the complex spin texture are incorporated into
the tunneling model. It is found that this effect modifies the apparent size of
the skyrmions. These results contribute to the proper identification of
topological surface magnetic objects imaged by SP-STM, and deliver important
parameters for current-induced spin dynamics.
