  We present long-slit H- and K-band spectroscopy of the low-mass outflow
source SVS 13, obtained with the adaptive-optics assisted imager-spectrometer
NACO on the VLT. With a spatial resolution of < 0.25 arcsec and a pixel scale
of 0.027 arcsec we precisely establish the relative offsets of H2, [FeII], CO,
HI and NaI components from the source continuum. The H2 and [FeII] peaks are
clearly associated with the jet, while the CO, HI and NaI peaks are spatially
unresolved and coincident with the source, as is expected for emission
associated with accretion processes. The H2 profile along the slit is resolved
into multiple components, which increase in size though decrease in intensity
with distance from the source. This trend might be consistent with thermal
expansion of packets of gas ejected during periods of increased accretion
activity. Indeed, for the brightest component nearest the source, proper motion
measurements indicate a tangential velocity of 0.028 arcsec/year. It therefore
seems unlikely that this emission peak is associated with a stationary zone of
warm gas at the base of the jet. However, the same can not be said for the
[FeII] peak, for which we see no evidence for motion downwind, even though
radial velocity measurements indicate that the emission is associated with
higher jet velocities. We postulate that the [FeII] could be associated with a
collimation shock at the base of the jet.
