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计划，以寻找一个统计上强大的样本的年轻的大规模星前核心测量22 GHz的水脉泽发射阶段的发病。本方案的科学目标是探测微波激射器发射阶段的最早"开启"阶段，这发生在（大多数？）大质量的年轻恒星，并在目标上不同于更常见的微波激射探测调查，已普遍进行了对许多星星形成地区的星系。使用我们的HERSCHEL保证时间计划中最新的精确位置/测辐射热光度/距离，我们将搜索一个精心挑选的大约附近核心的样本，主要是在南冕座，变色龙，苍蝇，狼疮，蛇夫座，船帆座和RCW 120中，以实现最终的灵敏度L（H2O）~几个10 - 9 - 10 - 8 Lsun。我们的三层观测策略将集中在附近（<1 kpc）具有良好特征的距离和演化阶段的原恒星核心，以提供统计稳健样本的远红外颜色/光度/演化状态参数空间的良好采样，这将回答微波激射发射首次开启的确切时间问题，将其与远红外特性所示的出生环境进行比较，以及使用23 GHz NH3线同时测量温度。

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.