Title:The Tully-Fisher relation as a tool to investigate the internal structure 
of galaxies

Abstract:
To investigate the internal structure of galaxies we consider in detail the 3.6 
μm Tully-Fisher relation taking advantage of spatially resolved HI velocity 
fields. The main idea is to abandon the classical concept of the Tully-Fisher 
relation as the correlation using the width of global HI profile, and consider 
instead the detailed internal kinematics of gas in galaxies. An improved 
kinematic measure is implemented by deriving hidh-quality rotation curves from 
the velocity fields, taking into account warps and streaming motions in the 
disk due to spiral arms or a bar. The decomposition of HI rotation curves into 
components will provide the mass distribution within the galaxies including 
baryonic and dark matter.