We report Mopra ( ATNF ) , Anglo-Australian Telescope , and Atacama Submillimeter Telescope Experiment observations of a molecular clump in Carina , BYF73 = G286.21+0.17 , which give evidence of large-scale gravitational infall in the dense gas .
From the millimetre and far-infrared data , the clump has mass \sim 2 \times 10 ^ { 4 } M _ { \odot } , luminosity \sim 2–3 \times 10 ^ { 4 } L _ { \odot } , and diameter \sim 0.9 pc .
From radiative transfer modelling , we derive a mass infall rate \sim 3.4 \times 10 ^ { -2 } M _ { \odot } yr ^ { -1 } .
If confirmed , this rate for gravitational infall in a molecular core or clump may be the highest yet seen .
The near-infrared K -band imaging shows an adjacent compact HII region and IR cluster surrounded by a shell-like photodissociation region showing H _ { 2 } emission .
At the molecular infall peak , the K imaging also reveals a deeply embedded group of stars with associated H _ { 2 } emission .
The combination of these features is very unusual and we suggest they indicate the ongoing formation of a massive star cluster .
We discuss the implications of these data for competing theories of massive star formation .