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Issue Title: Proceedings of the Fifth Stromlo Symposium: Disks, Winds and Jets - From Planets to Quasars We present three dimensional simulations of the interaction of a light hypersonic jet with an inhomogeneous thermal and turbulently supported disk in an elliptical galaxy. These simulations are applicable to the GPS/CSS phase of some extragalactic radio sources. We identify four generic phases in the evolution of such a jet with the interstellar medium. The first is a \"flood and channel\" phase, dominated by complex jet interactions with the dense cloudy medium close to the nucleus. This is characterized by high pressure jet gas finding changing weak points in the ISM and flowing through channels that form and reform over time. A spherical, energy driven, bubble phase ensues, wherein the bubble is larger than the disk scale, but the jet remains fully disrupted close to the nucleus, so that the jet flux is thermalised and generates a smooth isotropic energy-driven bubble. In the subsequent, rapid, jet break-out phase the jet breaks free of the last obstructing dense clouds, becomes collimated and pierces the more or less spherical bubble. In the final classical phase, the jet propagates in a momentum-dominated fashion similar to jets in single component hot haloes, leading to the classical jet-cocoon-bow-shock structure. [PUBLICATION ABSTRACT]

In this paper we examine the Direct Method for measuring electron temperatures in H II regions, and the extent to which such measurements can provide meaningful information on the physical conditions in these regions. We discuss the limits to what can be inferred about electron temperatures from nebular emission line fluxes. We provide a new simplified method for estimating electron temperatures, including parameters that can be used to determine this from UV [O III] and [O II] oxygen lines observable in high-redshift objects using ground-based telescopes. We test this method on published UV high redshift observations and compare the results with reported electron temperatures.

In order to better understand the formation of a starburst-driven wind, we have performed a series of three-dimensional hydrodynamical simulations in an inhomogeneous interstellar medium. We present the results of these simulations, which provide new insights into the formation of the optical filaments and the origin of the soft X-ray emission.

We create a photoionization model embedded in the turbulent ISM by using the state-of-the-art Messenger Monte-Carlo MAPPINGS~V code (M\\(^3\\)) in conjunction with the CMFGEN stellar atmosphere model. We show that the turbulent ISM causes the inhomogeneity of electron temperature and density within the nebula. The fluctuation in the turbulent ISM creates complex ionization structures seen in nearby nebulae. The inhomogeneous density distribution within the nebula creates a significant scatter on the spatially-resolved standard optical diagnostic diagrams, which cannot be represented by the spherical constant density photoionization model. We analyze the dependence of different optical emission lines on the complexity of nebular geometry, finding that the emission-lines residing on the nebular boundary are highly sensitive to the complexity of nebular geometry, while the emission-lines produced throughout the nebula are sensitive to the density distribution of the ISM within the nebula. Our fractal photoionization model demonstrates that a complex nebular geometry is required for accurate modeling of HII regions and emission-line galaxies, especially for the high-redshift galaxies, where the ISM is highly turbulent based on the increasing observational evidence.

Understanding the nucleosynthetic origin of nitrogen and the evolution of the N/O ratio in the interstellar medium is crucial for a comprehensive picture of galaxy chemical evolution at high-redshift because most observational metallicity (O/H) estimates are implicitly dependent on the N/O ratio. The observed N/O at high-redshift shows an overall constancy with O/H, albeit with a large scatter. We show that these heretofore unexplained features can be explained by the pre-supernova wind yields from rotating massive stars (M\\(\\gtrsim 10 \\, \\mathrm{M}_\\odot\\), \\(v/v_{\\rm{crit}} \\gtrsim 0.4\\)). Our models naturally produce the observed N/O plateau, as well as the scatter at low O/H. We find the scatter to arise from varying star formation efficiency. However, the models that have supernovae dominated yields produce a poor fit to the observed N/O at low O/H. This peculiar abundance pattern at low O/H suggests that dwarf galaxies are most likely to be devoid of SNe yields and are primarily enriched by pre-supernova wind abundances.