The study of Galactic radio nebulae with the Australian Square Kilometre Array Pathfinder

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In the lead-up to the highly anticipated Square Kilometre Array (SKA), several next generation radio telescopes are being built around the world. One of them is the Australian SKA Pathfinder (ASKAP). ASKAP is a radio interferometer located in Western Australia. It is equipped with newly developed focal plane arrays, which makes ASKAP the fastest survey radio telescopes in the world. ASKAP is currently in its commissioning and Early Science phase. A deep radio continuum survey, which will cover the entire southern sky, is planned on ASKAP. The Evolutionary Map of the Universe (EMU) in combination with the Polarization Sky Survey of the Universe's Magnetism (POSSUM) will observe a 300 MHz wide band centred at 950 MHz with full Stokes parameters. The primary objective of EMU is to understand the formation and evolution of galaxies over Cosmic time. Since EMU and POSSUM cover a large portion of the plane of our Galaxy, a Galactic Key Science project of EMU was formed of which I am the chair. The main goal of this Key Science project is to create a sensitive and complete atlas of discrete radio nebulae and analyse their properties. I am the principal investigator of an early science project (ESP9) which is scheduled for the second phase of EMU early science. The target is an area of the Galactic plane centred at Galactic longitude of 328 degrees. In early science, ASKAP observes the same area of the sky at three separate 300 MHz wide bands, covering most of the frequency range between 700 and 1800 MHz. This will give us the opportunity to study the objectives of full EMU in much more detail. The wide frequency range will enable us to develop techniques to separate Galactic from extragalactic sources and methods for the identification of Galactic nebulae with radio spectral and polarization properties. We can develop extraction software for diffuse, extended nebulae and test models for their analysis. The high sensitivity and resolution of EMU allows complete access to all stages of photo--ionized regions around massive stars. In particular, the optically thick hyper-compact kind that represents an early evolutionary phase when a massive star just “turned on” is poorly understood. We can detect and study the youngest, most compact supernova remnants (SNRs) and pulsar wind nebulae (PWNe) and find a solution to the missing SNR problem. We expect to increase the number of known radio planetary nebulae (PN) in this part of our Galaxy by a factor of 20. PNe are important for studies of the chemical, atomic, molecular and solid-state galactic ISM enrichment, giving us insight into the late evolutionary stages of low-mass stars. In addition POSSUM will produce a rotation measure (RM) catalogue of unprecedented size for compact polarized extragalactic sources. This dataset will provide a high resolution RM grid, which will open the door to study magnetic fields on all scales from&nbs