Dr Henry Lee will cover the following topics, amongst others:

- How the Gemini queue works
- Using Observing Condition constraints to your advantage
- Frequently-made mistakes in Phase 2 preparation

The format will be a presentation by Henry followed by a moderated question and answer session.

We'll be connecting to the Australian Gemini Office from the Meeting Room at CAS.

The formation and evolution of the Galactic bulge and its relationship with the other Galactic components is still poorly understood. To establish the chemical differences and similarities between the various populations, we present a homogeneous and differential elemental abundance analysis of bulge giant stars and halo, thin- and thick-disk high quality optical and near-infrared spectra of red giant stars in the solar neighborhood. In this talk, I will present the outcomes of this project, which reveal new clues about the chemical enrichment history of the Galactic bulge and thick disk.

The field of galaxy evolution has made enormous progress in the last two decades, to a large extent thanks to optical spectroscopic galaxy surveys. I will start by reviewing the physical information that allows us to extract star formation histories from optical spectra. I will then present some recent work on the role of gas-rich major mergers in the build-up of the red sequence since z~0.7, on the unspectacular recent star formation history of local AGN hosts, and the quenching mechanisms in SDSS clusters.

Both as high-energy astrophysical phenomena and as cosmological probes, type Ia supernovae are critical to our understanding of galaxy formation and evolution. For instance, feedback from supernovae directly influences the star-formation histories of galaxies at a wide range of masses, while also contributing significantly to the metal enrichment of the Universe. Despite much theoretical success in understanding the physics of type Ia events, recent measurements of the supernova Ia rate in local and intermediate-redshift galaxies have illustrated our remarkable ignorance regarding the nature of the type Ia progenitor population. In this talk, I will present results from a recent analysis of the large-scale environments of local type Ia supernovae, which provide an intriguing constraint on the properties of type Ia progenitors in star-forming galaxies.

During the last decade our understanding of the evolution of structure in the universe grew substantially. Due to the non-linear nature of the gravitational dynamics and the complicated gas-astrophysical processes numerical simulations on modern supercomputers have been the driving force behind much of this theoretical progress. Cosmological simulations must cover a large dynamical and mass range. A representative volume of the universe should be large, but this comes at the expense of the resolution. To overcome this problem a new, and almost orthogonal but yet complementary, approach to cosmological simulations has been introduced over the last few years. This consists of using observations of the nearby universe as constraints imposed on the initial conditions of the simulations. The resulting constrained simulations successfully reproduce the local large scale structure, where 'local' means a few tens of megaparsec around the Milky Way. These simulations are the numerical analog of the 'Near Field Cosmology', and provide a laboratory for studying the formation of our Local Group and its environment. I will review our constrained simulations performed in collaboration of research teams in Spain, Israel, Germany and USA and compare predictions of the cold and warm dark matter scenarios with recent observations.

Magnetic fields are thought to regulate the “accretion phase” of star formation. They do so by transporting away the excess angular momentum of the disk material, enabling it to accrete. The mechanisms responsible for this transport are not well understood, but the most promising are “turbulence viscosity” driven by the magnetorotational instability and “outflows” driven centrifugally from the disk surfaces. Both processes are, in turn, likely to play key roles in the structure, dynamics and evolution of protostellar disks. For example, magnetically driven turbulence is likely to have an effect on the transport and sedimentation of dust particles; in turn critical processes for the formation and migration of planets. In protostellar disks, however, the magnetic diffusivity may be high enough to prevent the magnetic field to effectively couple to the gas and drive these processes. As a result, in order to study the magnetic activity of these disks under realistic conditions, it is essential to consider carefully the conductivity of the gas and its spatial dependency. Our models of the radial (via the MRI) and vertical (via winds and outflows) angular momentum transport mechanisms in weakly ionized media incorporate the detailed ionization structure of the fluid and all relevant field-matter diffusion mechanisms. Here I examine the viability and properties of these processes in protostellar disks and present our solutions. Our results suggest that, despite the weak ionization, magnetic fields are dynamically important over a broad range of fluid conditions and field strengths in these objects.

Galaxies, like our own Milky Way, have grown over time through the accretion of smaller galaxies, and the remnants of ongoing accretions should be apparent within the Local Group. In this talk, I will present the results of an ongoing deep imaging survey of the haloes of our nearest large neighbours, M31 and M33, which has been coupled with stellar kinematics to reveal a spectacular wealth of streams, lumps and bumps which clearly illustrate that galaxy evolution is alive and well in the Local Group.

In the next decade the detection of gravitational waves will (hopefully) be a reality, opening a completely new window on the Universe. The primary actors on this upcoming stage are expected to be massive black hole binaries. After a short introduction about hierarchical galaxy and MBH formation, and GW detection, I will discuss the possibility of constraining black hole formation and cosmic evolution scenarios using the planned laser interferometer space antenna (LISA) and pulsar timing arrays (PTAs), assessing their capability of providing unique high (and low)-redshift information difficult to obtain by other means.

I will give a review of the current status of the Anglo-Australian Planet Search (AAPS). The AAPS is one of the oldest Doppler velocity planet searches in the world, having been running over 11 years. Throughout this time we have improved our velocity precision to ~1m/s or better. I will discuss both recent AAPS discoveries and my study of selection effects and observational biases; the latter has made use of the Swinburne supercomputer. I will also look at the future challenges to Doppler velocity programs, not least of which are the stars themselves.

We develop a new technique to extract galaxy halo light spectra at large galactocentric radii using the DEIMOS multi-object spectrograph. We use the metallicity sensitive Calcium triplet to obtain reliable metallicity gradients out to unprecedented radii (2.5r_e) in large early-type galaxies. The shape and slope of metallicity gradients with galactocentric radius contain information about the formation and evolution of galaxies. Results of our pilot study are presented and compared to theoretical models to constrain the processes involved in the formation and evolution of individual galaxies.

Bold colour images from telescopes act as extraordinary ambassadors for astronomers because they pique the public's curiosity. But are they snapshots documenting physical reality? Or are we looking at artistic spacescapes created by digitally manipulating astronomy images? This lecture provides a tour of how original black and white data from the Hubble Space Telescope, for example, are converted into the colour images gracing magazines. Each image is a battlefield where the attempt by scientists to represent their discoveries all but drowns out the voice of visual literacy. Yet sometimes in this battle, between the cultures of science and visual art, both sides win. This struggle will be presented from the perspective of a professional astronomer who has coordinated the Hubble Heritage Project and also trained as an artist. This lecture outlines how artistic techniques - such as colour contrast and composition - can be used by professional astronomers, inspired by the International Year of Astronomy 2009, to produce a more engaging image with greater clarity for the non-expert public.

We lack a thorough understanding, both observationally and theoretically, of how feedback from star formation, winds and inflows precisely affect the dynamics of galaxies and their extended halos. Here, we attempt to disentangle the rather complex coupling between these processes using both observations and simulations of extended gaseous galaxy halos. MgII absorption lines detected in the spectra of background quasars can be used to probe the kinematics and physical conditions in the halos of foreground galaxies. By comparing halo gas kinematics to the dynamics of the host galaxies themselves, a clear picture of the galaxy-halo relationship begins to emerge. We further compare the high quality absorption data and galaxy spectra with similarly-analyzed LCDM cosmological simulations. Together, they suggest a picture in which gaseous halos are chemically enriched by outflowing shock-heated supernovae winds while low metallicity gas inflowing along filaments produces an inhomogeneous temperature, velocity, and metallicity distributions with a non-unity gas covering fraction.

Several ongoing high-precision pulsar timing experiments are now regularly achieving timing precisions at the several hundred ns level, and sub-100-ns in the best cases. This has led to renewed worldwide interest in the idea of a pulsar timing array (PTA), where timing measurements of a group of MSPs are combined to act as a gravitational wave (GW) detector, sensitive to nHz-frequency GWs. The expected GW signal strength is in the 1-10 ns range, so a robust detection requires roughly an order of magnitude improvement in timing. In this talk I will describe the ongoing NANOGrav pulsar timing array project, the prospects for near-future PTA GW detection, and the challenges that we face in trying to achieve the next order of magnitude improvement. In particular, I will focus on recent work aimed at characterizing and removing the effect of the ionized intersterllar medium on pulsar timing.

Many galaxies display distinct, identifiable structural components: commonly (in massive systems) a central bulge and a surrounding disc, as well as bars, nuclei, and spiral arms. Moreover, the hierarchical clustering theory of galaxy formation postulates the existence of two fundamental evolutionary pathways: the cooling of gas inside rotating dark matter halos to form discs, and the merging of similar-sized discs to form spheroids and classical bulges. Hence, understanding the nature of these distinct structural components could prove crucial to understanding a range of galaxy formation processes. In this talk I will describe my recent and on-going work on automated structural decomposition of galaxy images regarding the relationship between galaxy structural type and position on the color-concentration bimodality, and discuss the implications of my results for contemporary formation scenarios.

Type Ia supernovae are the most important distance indicators used in astrophysics, and play an important role in constraining cosmological quantities. However, despite their use as 'standard candle' distance indicators, their origin remains uncertain. I will discuss the preliminary results from an ongoing study in which we have calculated the delay time distribution - time from star formation to time of SN Ia - for different SN Ia progenitor classes. I will compare the delay times resulting from different formation channels (single white dwarf and double white dwarf formation channels) for varying model parameters (e.g., common envelope removal efficiency). By comparing synthetic delay times with those which have been derived from observations, we aim to constrain the nature of the SN Ia progenitors.

I present a novel method of constraining AGN emission region size and emission mechanism, using recent optical--NIR imaging from the Magellan telescopes of four ``anomalous'' lensed quasars. Anomalous lensed quasars have an image pair in which one of the images is unusually ("anomalously") dim. We rule out millilensing and partial obscuration as causes for the anomalous flux ratio in each of our quasars, leaving microlensing as the only plausible alternative. We generate magnification maps for each image using a range of smooth-to-clumpy matter fractions. We then randomly select source positions on the map and calculate the magnifications of a set of Gaussian sources of varying width. We are thus able to constrain statistically, both the proportion of smooth-to-clumpy lensing material, and the size of the emitting region of the lensed source. Using this technique we have probed down to unprecedented scale lengths in the central engine (< 7 light days in r' band) and have begun to explore the change with wavelength. We find clear evidence of a decrease in source size with wavelength, and can place meaningful constraints on possible emission mechanisms.

When we originally discovered ultra-compact dwarf (UCD) galaxies in the Fornax and Virgo galaxy clusters their properties were clearly intermediate between the most luminous globular clusters and the smallest dwarf galaxies. Our favoured theory was that they were the stripped nuclei of nucleated dwarf galaxies. Five years on, the situation is not so clear, as I will discuss in this talk. The structural properites of UCDs in the "fundamental plane" show them to be clearly distinct from globular clusters, but their stellar populations show they mostly resemble globular clusters with old populations. Our dynamical simulations are consistent with some kind of disruptive formation process, but this would have to be from galaxies with unusually old nuclei. There are no solid theoretical predictions of how UCDs form, so we are now working with members of the Virgo Consortium to predict how UCDs could form using cosmological simulations.

Over the last decade observational cosmology has matured to the point where quantities such as the mass, composition and age of the Universe are now measured with a precision of a few percent. In contrast, the formation of the first galaxies remains very poorly understood. For example, we do not know at what time the first galaxies formed, what they looked like or how massive they were. The origins of this ignorance lie in observational difficulties associated with observing high redshift galaxies. However one fact is known. Three hundred thousand years after the Big-Bang the Universe was filled with atomic hydrogen, which was then reionized by starlight from the first galaxies over the next billion years. A new era for study of the first galaxies will therefore open with the next generation of low-frequency radio-telescopes, which will enable the reionization of the Universe to be studied directly. I will discuss some of the associated science, with some emphasis on the role that theory has played in motivating the experiments and the design of new telescopes like the MWA.

Each year the Australian Gemini Office coordinates the AGUSS scheme, sponsored by Astronomy Australia Ltd, to allow Australian undergraduate students to spend 10 weeks working at the Gemini South Observatory in Chile. At the conclusion of their program, the students present their results by video-conference to multiple sites in Australia. Everyone is welcome and encouraged to come and hear what this year's AGUSS students have been up to. David Palamara from Monash University will talk about infrared studies of globular cluster candidates in galaxy merger remnants, while Sophie Underwood from the University of Adelaide will talk about peculiar velocities of cluster galaxies.

(We'd be joining with video conferencing in the CAS meeting room. Live video streaming will be available from https://136.186.24.70/showstream.ssi to machines within Swinburne only)

Galaxies acquire motions that deviate from the universal expansion through gravitational interactions on a wide range of scales. The radial component of these deviant motions can be mapped with accurate measurements of distances. One of a variety of ways to measure distances makes use of the correlation between the luminosities of galaxies and their rotation rates. With appropriate photometric and spectroscopic information, the method can be applied to a majority of spiral galaxies. Samples of many thousands of galaxies can be acquired, giving the dense spatial coverage required to study the streams and eddies in the Cosmic Flow.

Recent developments at the AAO on both scientific and instrumentation fronts will be presented. These include research results from AAO staff, an overview of the ongoing AAT Large Programs (Anglo-Australian Planet Search, WiggleZ, GAMA), progress on the WFMOS concept study, the HERMES instrument, and a striking demonstration of the OH suppression fibre technology. Opportunities for students at the AAO will also be highlighted, including PhD top-up scholarships, as well as the currently open Magellan Fellow positions.

Cluster mergers are at the pinnacle of the large scale structure formation hierarchy, and involve the largest, most massive virialised objects at the present epoch. The effects of this violent merging environment on the cluster constituents (galaxies, intracluster medium and dark matter) are not well understood. Studies in this area are hindered by difficulties in determining whether a cluster is undergoing, or has recently undergone, a merger and distinguishing major mergers from minor. We have developed a new and innovative approach to solving these problems, whereby X-ray `Cold Fronts' detected in Chandra images are used as possible signposts of recent merger activity. In order to gain confidence in the use of cold fronts as `merger-o-meters', we have selected a sample of `Cold Front' clusters from the Chandra archive and are conducting extensive optical spectroscopy of these systems to verify (or otherwise) they have undergone a recent major merger event, and thereby explore the link between cluster dynamical evolution and the cluster galaxy evolution. In this talk I will present the Cold Front sample, its selection criteria and describe the studies we have undertaken with the AAT/AAOmega and MMT/Hectospec spectrographs of two important test cases: Abell 1201 and Abell 3667. For these two clusters I will present methods and results of the sub-structure detection analysis and show a causal link between the observed cold fronts and plausible merger histories.