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

尽管它们的初始和内部条件不同，但大多数星团中恒星的质量分布(通常称为初始质量函数或IMF)非常相似。此外，大约十年前，研究表明，最年轻恒星和恒星前体的质量分布(通常被称为核心质量函数或CMF)遵循与IMF相同的形状。这证明了对模拟恒星形成的理论家的一个重要限制：他们必须在模拟的所有阶段恢复天体质量的这种分布。由于以前的手段限制了大型和/或敏感的地图需要大量的时间，进一步探索CMF和IMF之间的相似性受到了阻碍。詹姆斯·克莱克·麦克斯韦望远镜(JCMT)上的Scuba-2绘制天空地图的速度将比以前的仪器快数百倍，使天文学家能够绘制出测量天空的巨大地图。我们的项目旨在首次使用Scuba-2测量棕矮星质量的CMF-我们不知道CMF形状的区域。CMF的形状是否会继续反映IMF的形状--这意味着低质量恒星核的形成方式与褐矮星相同？事实上，我们在低质量处发现的核心将是一个新的、独特的群体，可能是迄今为止被发现的最年轻的天体。这些天体的速度和密度条件决定了随后崩塌形成恒星的细节。在最近的共同风险呼吁中，我们获得了10小时的潜水望远镜时间，以在附近的尘埃和气体云(朝着英仙座)解决这些问题，这是已知的正在形成恒星的星云。Scuba-2前所未有的灵敏度和测绘速度将使我们能够找到比该地区以前看到的轻约50倍的岩心。我们请求支持一名观察员(Scuba-2项目的PI)前往夏威夷进行我们排名较高的观测。这次旅行包括在联合天文中心(JAC)工作人员建议的运行之前花一天时间让观测者熟悉软件和数据简化。亲自出行对于利用Scuba-2制定最佳观测战略和数据简化程序至关重要，鉴于它是一种如此新和复杂的仪器，目前尚不清楚这一点。

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.