Support for observing at the JCMT: SCUBA-2 shared risks observing of Perseus (project M09BI127)

Despite their different initial and internal conditions, the mass distribution of stars in most stellar clusters (typically called the initial mass function or IMF) are remarkably similar. Furthermore around a decade ago it was shown that the mass distribution of the youngest stars and stellar precursors (often called the core mass function or CMF), follows the same shape as the IMF. This has proved an important constraint for theoreticians modelling the formation of stars: they must recover this distribution of object masses at all stages in their simulations. Probing the similarity between the CMF and IMF further has been hindered by the limitations in previous instrumentation ensuring large and/or sensitive maps take a prodigious amount of time. SCUBA-2 on the James Clerk Maxwell telescope (JCMT) will be many hundreds of times faster at mapping the sky than previous instruments, allowing astronomers to make vast maps surveying the sky. Our project aims to use SCUBA-2 to measure the CMF at brown-dwarf masses for the first time - regions where we do not know the shape of CMF. Will the shape of the CMF continue to mirror that of the IMF - implying low-mass stellar cores form in the same way as brown dwarf stars? In fact the cores we discover at low masses will be a new and unique population probably the youngest objects that will go on to be stars identified to date. The velocity and density conditions in these objects crucially set the details of the ensuing collapse to form a star. We have been awarded 10 hours of telescope time with SCUBA-2 during the recent shared-risk call to address these questions in a nearby cloud of dust and gas (towards the Perseus constellation) that is known to be forming stars. The unprecedented sensitivity and mapping speed of SCUBA-2 will allow us to find cores approximately 50 times lighter than seen before in this region. We request support for one observer (the PI of the SCUBA-2 project) to travel to Hawaii to undertake our highly-ranked observations. The trip includes a day spent at the Joint Astronomy Centre (JAC) before the run for the observer to become familiar with the software and data reduction, as recommended by JAC staff. An in-person trip is essential to develop the optimum observing strategy and data reduction procedures with SCUBA-2, which are currently unclear given it is such a new and complex instrument.