PATT Travel Grant request to support observations for the Programme 'Switched on Water Masers' at the Parkes 60 metre Telescope, Australia

我们提出了一个敏感的帕克斯程序来搜索一个统计上可靠的年轻大质量恒星前核心样本，以测量22 GHz水激射相位的开始。这项提议的科学目标是探测发生在（大多数？）大质量年轻恒星中的脉泽发射阶段的“开启”的最早阶段，其目标与更常见的对星系中许多恒星形成区域进行的脉泽探测调查不同。利用我们的HERSCHEL保证时间计划的最新精确位置/热光度/距离，我们将仔细选择大约附近的岩心样本，主要是在南冕、变色龙、Musca、Lupus、蛇夫座、船帆座和RCW120，以获得最终的灵敏度L(H2O) ~几个10-9 - 10-8 Lsun。我们的三级观测策略将集中在附近（< 1 kpc）的原恒星核心，具有良好的距离和演化阶段特征，提供良好的远红外颜色/亮度/演化状态参数空间的统计可靠样本，这将回答微波激射发射何时开始的问题，并将其与远红外特性所显示的出生环境进行比较。以及使用23 GHz NH3线路同时测量温度。

We propose a sensitive Parkes Programme to search a statistically robust sample of young massive prestellar cores to measure the onset of the 22 GHz water maser-emitting phase. The sceince objective of this proposal is to detect the very earliest stages of the 'switch-on' of the maser emitting phase that occurs in (most ?) massive young stars, and differs in objective to the more usual maser detection surveys that have been commonly carried out towards many star formation regions in the galaxy. Using the latest accurate positions/bolometric luminosities/distances from our HERSCHEL Guaranteed time programmes, we will search a carefully selected sample of about nearby cores, mostly in Corona Australis, Chamaeleon, Musca, Lupus, Ophiuchus, Vela and RCW120, to achieve a final sensitivity L(H2O) ~ a few 10-9 - 10-8 Lsun. Our three tiered observing strategy will focus on for nearby (< 1 kpc) protostellar cores with well characterised distances and evolutionary phases, to provide good sampling of far-IR colour/luminosity/evolutionary state parameter space of a statistically robust sample that will answer the question of exactly when maser emission first switches on, comparing this with its natal environment as shown by the far-infrared properties, and from simultaneous measurements of temperature using the 23 GHz NH3 lines.