We present Br \gamma emission line kinematics of the nuclear region of NGC 253 , recently known to host a strong galactic wind that limits the global star formation of the galaxy .
We obtained high-resolution long-slit spectroscopic data with PHOENIX at Gemini-South , positioning the slit on the nucleus Infrared Core ( IRC ) , close to the nuclear disk major axis .
The spatial resolution was 0.35 \arcsec ( \sim 6 pc ) and the slit length was 14 \arcsec ( \sim 240 pc ) .
The spectral resolution was \sim 74000 , unprecedentedly high for galactic nuclei observations at \sim 2.1 \mu m. The line profiles appear highly complex , with blue asymmetry up to 3.5 \arcsec away of the IRC , and red asymmetries further away to NE .
Several Gaussian components are necessary to fit the profile , nevertheless a narrow and a wide ones predominate .
The IRC presents kinematic widths above 700 km s ^ { -1 } ( FWZI ) , and broad component FWHM \sim 400 km s ^ { -1 } , the highest detected in a nearby galaxy .
At the IRC , the blue-shifted broad component displays a 90 km s ^ { -1 } bump in radial velocity distribution , a feature we previously detected in molecular gas kinematics .
The narrow component velocity dispersion ( \sim 32 km s ^ { -1 } ) is within the expected for normal galaxies and LIRGs .
Intermediate components ( FWHM \sim 150 km s ^ { -1 } , red-shifted to the NE , blue-shifted to the SW ) appear at some positions , as well as weaker blue ( -215 km s ^ { -1 } ) and red line wings ( +300 km s ^ { -1 } ) .
The IRC depicts a large broad-vs-narrow line flux ratio ( F ( B ) /F ( N ) \sim 1.35 ) , and the broad component seems only comparable with those observed at very high star-forming rate galaxies .
The results indicate that the IRC would be the main source of the galactic winds originated in the central region of NGC 253 .