Star formation in a high-pressure environment: An SMA view of the
  Galactic centre dust ridge
  The star formation rate in the Central Molecular Zone (CMZ) is an order of
magnitude lower than predicted according to star formation relations that have
been calibrated in the disc of our own and nearby galaxies. Understanding how
and why star formation appears to be different in this region is crucial if we
are to understand the environmental dependence of the star formation process.
Here, we present the detection of a sample of high-mass cores in the CMZ's
"dust ridge" that have been discovered with the Submillimeter Array as part of
the CMZoom survey. These cores range in mass from ~ 50 - 2150 Msun within radii
of 0.1 - 0.25 pc. All appear to be young (pre-UCHII), meaning that they are
prime candidates for representing the initial conditions of high-mass stars and
sub-clusters. We report that at least two of these cores ('c1' and 'e1')
contain young, high-mass protostars. We compare all of the detected cores with
high-mass cores in the Galactic disc and find that they are broadly similar in
terms of their masses and sizes, despite being subjected to external pressures
that are several orders of magnitude greater - ~ 10^8 K/cm^3, as opposed to ~
10^5 K/cm^3. The fact that > 80% of these cores do not show any signs of
star-forming activity in such a high-pressure environment leads us to conclude
that this is further evidence for an increased critical density threshold for
star formation in the CMZ due to turbulence.
