NIR jets from a clustered region of massive star formation: Morphology
  and composition in the IRAS 18264-1152 region
  Massive stars form deeply embedded in their parental clouds, making it
challenging to directly observe these stars and their immediate environments.
It is known that accretion and ejection processes are intrinsically related,
thus observing massive protostellar outflows can provide crucial information
about the processes governing massive star formation close to the central
engine. We aim to probe the IRAS 18264-1152 (G19.88-0.53) high-mass
star-forming complex in the near infrared (NIR) through its molecular hydrogen
(H2) jets to analyse the morphology and composition of the line emitting
regions and to compare with other outflow tracers. We observed the H2 NIR jets
via K-band (1.9-2.5um) observations obtained with the integral field units
VLT/SINFONI and VLT/KMOS. SINFONI provides the highest NIR angular resolution
achieved so far for the central region (~0.2''). We compared the geometry of
the NIR outflows with that of the associated molecular outflow probed by CO
(2-1) emission mapped with SMA. We identify nine point sources. Four of these
display a rising continuum in the K-band and are BrG emitters, revealing that
they are young, potentially jet-driving sources. The spectro-imaging analysis
focusses on the H2 jets, for which we derived visual extinction, temperature,
column density, area, and mass. The intensity, velocity, and excitation maps
based on H2 emission strongly support the existence of a protostellar cluster,
with at least two (and up to four) different large-scale outflows. The
literature is in agreement with the outflow morphology found here. We derived a
stellar density of ~4000 stars pc^-3. Our study reveals the presence of several
outflows driven by young sources from a forming cluster of young, massive
stars. The derived stellar number density together with the geometry of the
outflows suggest that stars can form in a relatively ordered manner in this
cluster.
