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NOTE SPECIAL TIME 11AM - Abstract: I describe the latest developments with the construction of ASKAP and the Murchison Radioastronomy Observatory. I will also provide an overview of some of the ASKAP survey science programs.

NOTE SPECIAL DATE TUE 15/05. Abstract: Theories which describe the physics of the early Universe frequently include scenarios for the production of gravitational waves. For cosmic superstring models, gravitational waves which survive to the current epoch would have resulted from the superposition of a large number of unresolved sources while, more generically, gravitational wave production might be related to the equation of state characterizing matter and energy in the very early Universe. Whatever cosmic physics model is actually responsible for creating a stochastic background of gravitational waves, we can expect its unique imprint to be evident today, just as the thermal history of the early Universe has imposed a unique black body temperature, and a precise fluctuation spectrum, on the cosmic microwave background (CMB). Direct measurement of the amplitude of a stochastic GW background is therefore of fundamental importance for understanding the evolution of the Universe during its earliest moments, when it was undergoing processes which are inaccessible to more standard astrophysical observations. I report on recently published limits on the amplitude of the stochastic gravitational-wave background, using the data from a two-year science run of the Laser Interferometer Gravitational-wave Observatory (LIGO). The result constrains the energy density of the stochastic gravitational-wave background normalized by the critical energy density of the Universe, in the frequency band around 100Hz, to be less than 6.9x10^-6 at 95% confidence. Impact on several models for the early Universe is discussed.

Most extragalactic star clusters have a scale size narrowly centered around three parsecs, similar to their Galactic counterparts. In the last decade, however, a rush of discovery of new stellar systems, brighter,larger, and more massive than "standard" globular clusters has taken
place. The scale sizes of globular clusters, extended star clusters and ultra-compact dwarfs in the Coma cluster, and the fossil group NGC 1132 will be presented. The results of N-Body simulations helps us to understand the physical mechanisms that determine the scale-sizes of
star clusters and compact stellar systems in general.

Core collapse supernova events play a critical role in the chemical enrichment of our Universe and produce many of the critical elements needed for life to form on other planets. The stars that produce these events comprise less than a tenth of one percent of star in a typical galaxy and have lifetimes shorter than ten million years, making them very rare events in a galaxy like our Milky Way. To explore the evolution of these massive stars and how they play a role in forming new stars, we must look beyond our own galaxy, typically 10-100 million light years away. At these distances, it is practically impossible to predict which stars which explode until they have already done so. However, after the explosion, there is sometimes radio and X-ray emission produced as the supernova blast wave over runs the stellar winds shed by the star in the thousands of years prior to its death. I will present a summary of how astronomers at the Australian Telescope Compact Array and the Very Large Array use this radio emission to constrain and determine the pre-explosion evolution and environment of these massive supernova progenitor stars, as young as a few months and as old as seventy-five years after the supernova explosion.

Despite a lack of comprehensive observational support, AGN feedback has become a key component of modern theories of galaxy formation. Much of this development is due to theoretical insight gained from simulations of galaxy formation that include both star formation and AGN feedback. Yet while feedback from star formation is moderately well understood, AGN feedback is not. There are uncertainties in the physics (how does accretion actually occur? What is the duty cycle and intermittency of feedback?) and also uncertainties in how it should be implemented numerically. In this talk I will present results from an ongoing project to compare and contrast different approaches to modelling AGN feedback. I'll highlight where the greatest uncertainties are (e.g. is it black hole tracking, or modelling the accretion?) and what the prospects are for addressing some of these issues.

Abstract: Today, the Cassini-Huygens Mission to Saturn and Titan is slowly unravelling the mysteries of Saturn and its remarkable satellite system. Saturn’s largest satellite Titan is more like a planet than a moon. Its mass is nearly 60 times larger than that of the second largest moon Saturnian Rhea and its physical size exceeds that of Mercury. Titan is also unique because of its thick atmosphere which is 4 times denser than that of the Earth at its surface.
In this talk I discuss the formation of the planetary system and the satellite system of Saturn within the context of the ‘Modern Laplacian Theory’ of solar system origin. According to this model, the planets condensed form an orbiting family of gas rings that had been shed by the gravitationally contracting proto-solar cloud, some 4.6 billion years ago.

Young core-collapse supernova remnants (SNRs) interact with circumstellar medium that the progenitors injected during their final stages of evolution. As such they provide invaluable opportunity to investigate the final moment of massive stars as well as the explosion
itself. In this talk, I will first discuss how the morphology and physical characteristics of young core-collapse SNRs are determined by the mass-loss history of progenitors. Then I will introduce three young SNRs, i.e., G11.2-0.3, G54.1+0.3, and MSH 15-52, which are thought to be the remnants of SN IIL/b (or IIn), IIP, and Ib/c, respectively. These three SNRs illustrate how diverse the environments of young SNRs are, and, on each of them, recent observations from ground-based near-infrared observatories and space-infrared telescopes revealed interesting results.

In this talk I will describe some of the basic measurables of radio pulsars and how they have led to discovery of transient phenomena on timescales from milliseconds to decades. Long term variability has implications on our ability to precisely model the rotational properties of pulsars and the physical phenomena occurring at the pulsar. On the shortest time scales, discovery of radio transients has the potential to reveal new pulsar populations, as well as provide new
means to study supernovae and GRBs. In this context, I will present a fast transient detection system developed for LOFAR, after briefly introducing this new telescope and its early science achievements in pulsar and fast transient astrophysics.

Abstract: We apply CMB lensing techniques to large scale structure and solve for the 3-D cosmic tidal field. We use small scale filamentary structures to solve for the large scale tidal shear and gravitational potential. By comparing this to the redshift space density field, one can measure the gravitational growth factor on large scales without cosmic variance. This potentially enables accurate measurements of neutrino masses.

I will discuss the new paradigm for the assembly of galaxies and their globular cluster (GC) systems emerging from recent theoretical work and supported by our imaging and spectroscopic data from the SLUGGS and SMEAGOL surveys of GCs and starlight out to many effective radii in nearby early type galaxies. Data obtained with Suprime-Cam on Subaru and DEIMOS on Keck are compared to a variety of simulations of galaxy build-up. Kinematic signatures, as well as metallicity and surface density distributions of the GCs and the underlying galaxy starlight support and constrain two-phase galaxy formation scenarios. Early "in situ" formation and subsequent minor mergers may be the dominant mechanisms for building galaxies and their GC systems. Later major mergers may have been important only in a small minority of cases. I will also explore the relationships between compact stellar systems, including a newly discovered class of faint ultra compact dwarfs (UCDs) that may be markers of the halo assembly process.

Lyman Break Galaxies (LBGs), easily found at higher redshifts due to the sharp drop in their spectral energy distribution shortwards of Lyman-alpha, are commonly observed and studied at almost all redshifts from z=0.3 out to the highest redshifts. LBGs with Ly-alpha emission (LAEs) are of particular interest as they allow to derive accurate spectroscopic redshifts, and as a result of that essentially all galaxies with spectroscopic redshifts z>3 (where strong rest-frame optical emission lines are shifted into the near-to-mid infrared and hence hard to observe from the ground) are also LBGs. However, the underlying processes that governs the strength of Ly-alpha is still under debate, as Ly-alpha is readily absorbed and scattered by even minute amounts of hydrogen within and around galaxies. Understanding the escape mechanism for Ly-alpha therefore offers insights into the physical conditions within and around the respective galaxies.Here we use a large sample of restframe UV spectra of ~1000 LBGs at redshifts z=1.5-3 to investigate the connection between Ly-alpha emission and the properties of their host galaxies and the evolution of these trends with redshift from z=2 to z=3. We find that LAEs are, on average, have smaller star formation rates, older ages, and less dust reddening then their LBG counterparts without Ly-alpha emission. Comparing the observed Ly-alpha luminosity to the Ly-alpha luminosity expected from their UV-derived star formation rate we find a dust-corrected escape fraction of the order of 10% independent of redshift.

The Central Molecular Zone (CMZ) contains the richest molecular environment of our Galaxy. Spread over the central ~450x150 parsecs of the Galaxy is found ~50 million solar masses of molecular material. This environment is denser, warmer and more turbulent than that found in the giant molecular clouds of the Galaxy's spiral arms. Surprisingly, the CMZ is also a rich source of organic molecules, and these are found widely distributed across it, and not just confined to the densest cores as they are in GMCs. Until recently we have lacked the ability to examine closely this organic repository at the centre of our Galaxy. Now, with the 22m Mopra millimetre-wave telescope in Australia, we have undertaken a multiple molecular line survey of the CMZ, mapping simultaneously the distribution and dynamics of 18 molecular lines, emitting from 85-93 GHz, across a 2.5°x0.5° region of the CMZ. This work complements the continuum view from radio, infrared, x-ray and gamma- rays of this exotic and multi-facetted environment. We report on the view that is now emerging of the CMZ, our closest galactic nucleus and the only one we can resolve in detail.

I will present recent results using the baryon acoustic oscillation (BAO) signal in the Sloan Digital Sky Survey (SDSS) DR7 sample. I will discuss the first application of the idea of density-field reconstruction to the BAO signal. Given these measurements, I will then describe how we robustly derive distance constraints from the galaxy correlation function. Applying these methods to the DR7 data yields a 2% distance measurement to z=0.35, a factor of 1.8 improvement over the unreconstructed case. I will finally discuss the cosmological implications of these measurements and then conclude with the outlook for future surveys.

Abstract: One of the biggest puzzles in galaxy formation is not why galaxies form stars, but rather why some of them do not. I will review results from analysis of the spectra of low-redshift red galaxies (including data ultra-deep spectra in the Coma Cluster) which reveal where, when and how quickly these galaxies died. In particular, by comparing results with orbital data from N-body simulations, we disentangle internal from environmental effects.

Abstract: Cataclysmic Variables (CVs) are usually defined to be white dwarfs (WD) accreting matter from a Roche-lobe filling companion. Accretion disk instabilities in CVs lead to dwarf nova eruptions. The 25-year old hibernation scenario of cataclysmic binary evolution posits that all dwarf novae must eventually erupt as thermonuclear runaway classical novae; and that classical novae eventually revert to being dwarf novae and then "hibernating" CVs. Recent observations provide some spectacular confirmations of the theory. One of the leading candidates for SNIa progenitors has been a special type of CV: the recurrent nova. Just published HST images are an acid test for the model, and convincingly resolve the nature of SNIa progenitors.

Abstract: Circumstellar disks appear in the early phases of formation of stars and play a key role in the assembly of the final mass of the central star and in the possible formation of a planetary system around it. I will review our understanding of the properties and evolution of disks around young stellar objects, focusing on the solids (dust and pebbles) in disk. The evolution of the solids is directly related to the initial stages of planets formation as grains are expected to grow to large pebbles and form planetesimals and rocky cores of planets. I will discuss the current observational evidence for grain evolution in disks, the difficulties and
success of theoretical models to explain observations and the latest ideas on grain populations segregation in disks. I will discuss future observational tests, in particular with ALMA Early Science and beyond, that will allow us to impose tighter constraints on models of solids evolution in disks.
I will also present the status and future development of ALMA. In particular I will give an update on Science Verification, Early Science and the expectations for Cycle 1 and the timeline for full science operations and beyond.

This will be followed by a discussion on PanSTARRS