Multiple molecular outflows and fragmentation in the IRDC core
  G34.43+00.24 MM1
  The fragmentation of a molecular cloud that leads to the formation of
high-mass stars occurs on a hierarchy of different spatial scales. The large
molecular clouds harbour massive molecular clumps with massive cores embedded
in them. The fragmentation of these cores may determine the initial mass
function and the masses of the final stars. Therefore, studying the
fragmentation processes in the cores is crucial to understand how massive stars
form. The hot molecular core G34-MM1, embedded in IRDC G34.34+00.24 located at
a distance of 3.6 kpc, is a promising object to study both the fragmentation
and outflow processes. Using data at 93 and 334 GHz obtained from the Atacama
Large Millimeter Array (ALMA) database we studied G34-MM1 with great detail.
The angular resolution of the data at 334 GHz allowed us to resolve structures
of about 0.014 pc ($\sim$2900 au). We found evidence of fragmentation towards
the molecular hot core G34-MM1 at two different spatial scales. The dust
condensation MM1-A (about 0.06 pc in size) harbours three molecular subcores
candidates (SC1 through SC3) detected in $^{12}$CO J=3-2 emission, with typical
sizes of about 0.02 pc. From the HCO$^+$ J=1-0 emission, we identify, with
better angular resolution than previous observations, two perpendicular
molecular outflows arising from MM1-A. We suggest that subcores SC1 and SC2,
embedded in MM1-A, harbour the sources responsible of the main and the
secondary molecular outflow, respectively. Finally, from the radio continuum
emission at 334 GHz, we marginally detected another dust condensation, named
MM1-E, from which a young, massive, and energetic molecular outflow arises. The
fragmentation of the hot molecular core G34-MM1 at two different spatial
scales, together with the presence of multiple molecular outflows associated
with it, would support a competitive accretion scenario.
