We present two absolute magnitude calibrations, MJ and MK s, for red giants with the colour–magnitude diagrams of five Galactic clusters with different metallicities, i.e. M92, M13, M71, M67, and NGC 6791. The combination of the absolute magnitudes of the red giant sequences with the corresponding metallicities provides calibration for absolute magnitude estimation for red giants for a given colour. The calibrations for MJ and MK s are defined in the colour intervals 1.3≤(V−J)0≤2.8 and 1.75≤(V−K s)0≤3.80 mag, respectively, and they cover the metallicity interval −2.15≤[Fe/H]≤+0.37 dex. The absolute magnitude residuals obtained by the application of the procedure to another set of Galactic clusters lie in the intervals −0.08<ΔMJ ≤+0.34 and -0.10< Δ MK s≤ +0.27 mag for MJ and MK s, respectively. The means and standard deviations of the residuals are 〈ΔMJ 〉=0.137 and σMJ =0.080, and $〈 Δ MK s〉 =0.109 and σMK s=0.123 mag. The derived relations are applicable to stars older than 4 Gyr, the age of the youngest calibrating cluster.

Taking into account the results obtained from the models and analyses of the BVRI light curves, we discuss the nature of V1464 Aql. The analyses indicated that the mass ratio of the system is q = 0.71 ± 0.02, while the inclination of the system (i) is 38°.45 ± 0°.22. Taking the primary component’s temperature as 7420 ± 192 K, we found that the temperature of the secondary is 6232 ± 161 K. The mass of the primary component was found to be 1.74 ± 0.05 M⊙, while it is 1.23 ± 0.01 M⊙ for the secondary. The primary component’s radius was found to be 2.10 ± 0.05 R⊙, while it was found as 1.80 ± 0.01 R⊙ for the secondary. Revealing that the system should not exhibit any eclipses, we demonstrated that the main variation with large amplitude should be caused due to the ellipsoidal effect. Indeed, the Fourier analysis also supported the result. For the first time in the literature, we revealed that the primary component is a δ Scuti star. The period of pulsation was found to be 58.482 ± 0.002, 58.482 ± 0.001, 60.966 ± 0.002, and 60.964 ± 0.003 min in BVRI bands, respectively. We plotted V1464 Aql in the log (P orb)–log (P pulse) plane. Using more than 160 binaries, whose one or both components are pulsating, we derived a new linear fit in the log (P orb)–log (P pulse) plane for each type of binary. Using the linear fit of each group, we obtained new calibrations between log (P orb) and log (P pulse) for different types of pulsating stars. In addition, a calibration has been obtained for the first time for the pulsating stars with spectral types O and B. V1464 Aql seems to be located near the other ellipsoidal and close binaries. Thus, we listed V1464 Aql as a new candidate for the ellipsoidal variables with a δ Scuti component.

Measurements of the optical turbulence profile above Siding Spring Observatory were conducted during 2005 and 2006. This effort was largely motivated by the need to predict the statistical performance of adaptive optics at Siding Spring. The data were collected using a purpose-built instrument based on the slope detection and ranging (SLODAR) method where observations of a bright double star are imaged by Shack–Hartmann taken with the Australian National University 24-inch and 40-inch telescopes. The analysis of the data yielded a model consisting of a handful of statistically prominent thin layers that are statistically separated into the ground layer (37.5, 250 m) and the free atmosphere (1, 3, 6, 9, 13.5 km) for good (25%), typical (50%), and bad (25%) observing conditions. We found that ground-layer turbulence dominates the turbulence profile with up to 80% of the integrated turbulence below 500 m. The turbulence tends to be non-Kolmogorov, especially for the ground layer with a power-law index of β ~ 10/3. The mirror/dome seeing can be a significant fraction of the ground-layer turbulence. The median atmospheric seeing is around 1.2 arcsec, in agreement with observational reports.

Using an observationally derived model of optical turbulence profile, we have investigated the performance of adaptive optics (AO) at Siding Spring Observatory, Australia. The simulations cover the performance for AO techniques of single-conjugate adaptive optics (SCAO), multi-conjugate adaptive optics (MCAO), and ground-layer adaptive optics (GLAO). The simulation results presented in this paper predict the performance of these AO techniques as applied to the Australian National University (ANU) 2.3-m and Anglo-Australian Telescope (AAT) 3.9-m telescopes for astronomical wavelength bands J, H, and K. The results indicate that the AO performance is best for the longer wavelengths (K band) and in the best seeing conditions (sub 1 arcsec). The most promising results are found for GLAO simulations (field of view of 180 arcsec), with the field RMS for encircled energy 50% diameter (EE50d) being uniform and minimally affected by the free-atmosphere turbulence. The GLAO performance is reasonably good over the wavelength bands of J, H, and K. The GLAO field mean of EE50d is between 200 and 800 mas, which is a noticeable improvement compared with the nominal astronomical seeing (870–1 700 mas).

In coming years, Australia may find the need to build new optical telescopes to continue local programmes, contribute to global survey projects, and form a local multi-wavelength connection for the new radio telescopes being built. In this study, we refine possible locations for a new optical telescope by studying remotely sensed meteorological infrared data to ascertain expected cloud coverage rates across Australia, and combine these data with a digital elevation model using a geographic information system. We find that the best sites within Australia for building optical telescopes are likely to be on the highest mountains in the Hamersley Range in northwest Western Australia, while the MacDonnell Ranges in the Northern Territory may also be appropriate. We believe that similar seeing values to Siding Spring should be obtainable and with significantly more observing time at the identified sites. We expect to find twice as many clear nights as at current telescope sites. These sites are thus prime locations for future on-site testing.

An adaptive algorithm is presented for the wavelength calibration of the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST). The new algorithm can identify emission lines of calibration lamp without manual interaction and then fit relationship between the pixel positions and the wavelengths by utilizing a polynomial function. In this study, experiments are performed both on the actual data observed by LAMOST and the simulated data to analyze the accuracy and the robustness.The experimental results show that the proposed automatic algorithm can perform the lines identification exactly and acquire the wavelength solution accurately. Thus, an applicable approach is provided for the wavelength calibration of LAMOST.

This paper reviews what has been learned about the old stellar population of NGC 5128, the only large elliptical galaxy close enough that we can currently observe individual stars as faint as the horizontal branch. Although its galaxy type is still a matter of debate, the uncertainties over distance are now largely resolved; comparison of five stellar distance indicators gives d= 3.8±0.1 Mpc. The globular cluster system, which was once perplexingly invisible, is now known to be predominantly old with a substantial metal-rich component. The globular cluster system (GCS) total population and luminosity function are normal and the clusters follow the same fundamental plane relation as those in the Milky Way and M31. Finally, the halo out to at least ∼7reff is dominated by metal-rich stars which are also predominantly old, with age and metallicity tantalizingly similar to the majority of globular clusters.

The Australian Square Kilometre Array Pathfinder (ASKAP) presents a number of challenges in the area of source finding and cataloguing. The data rates and image sizes are very large, and require automated processing in a high-performance computing environment. This requires development of new tools, that are able to operate in such an environment and can reliably handle large datasets. These tools must also be able to accommodate the different types of observations ASKAP will make: continuum imaging, spectral-line imaging, transient imaging. The ASKAP project has developed a source-finder known as selavy, built upon the duchamp source-finder. selavy incorporates a number of new features, which we describe here.

Since distributed processing of large images and cubes will be essential, we describe the algorithms used to distribute the data, find an appropriate threshold and search to that threshold and form the final source catalogue. We describe the algorithm used to define a varying threshold that responds to the local, rather than global, noise conditions, and provide examples of its use. And we discuss the approach used to apply two-dimensional fits to detected sources, enabling more accurate parameterisation. These new features are compared for timing performance, where we show that their impact on the pipeline processing will be small, providing room for enhanced algorithms.

We also discuss the development process for ASKAP source finding software. By the time of ASKAP operations, the ASKAP science community, through the Survey Science Projects, will have contributed important elements of the source finding pipeline, and the mechanisms in which this will be done are presented.

A heuristic greedy algorithm is developed for efficiently tiling spatially dense redshift surveys. In its first application to the Galaxy and MassAssembly (GAMA) redshift survey we find it rapidly improves the spatial uniformity of our data, and naturally corrects for any spatial bias introduced by the 2dF multi-object spectrograph. We make conservative predictions for the final state of the GAMA redshift survey after our final allocation of time, and can be confident that even if worse than typical weather affects our observations, all of our main survey requirements will be met.

In this review I summarise recent advances in our understanding of the importance of starburst events to the evolutionary histories of nearby galaxies. Ongoing bursts are easily diagnosed in emission-line surveys, but assessing the timing and intensity of fossil bursts requires more effort, usually demanding color–magnitude diagrams or spectroscopy of individual stars. For ages older than ∼1 Gyr, this type of observation is currently limited to the Local Group and its immediate surroundings. However, if the Local Volume is representative of the Universe as a whole, then studies of the age and metallicity distributions of star clusters and resolved stellar populations should give statistical clues as to the frequency and importance of bursts to the histories of galaxies in general. Based on starburst statistics in the literature and synthetic colour-magnitude diagram studies of Local Group galaxies, I attempt to distinguish between systemic starbursts that strongly impact galaxy evolution and stochastic bursts that can appear impressive but are ultimately of little significance on gigayear timescales. As a specific case, it appears as though IC 10, the only starburst galaxy in the Local Group, falls into the latter category and is not fundamentally different from other nearby dwarf irregular galaxies.

We review our recent studies of the globular cluster system of NGC 5128. First, we have obtained low-resolution, high signal-to-noise spectroscopy of 72 globular clusters using Gemini-S/GMOS to obtain the ages, metallicities, and the level of alpha enrichment of the metal-poor and metal-rich globular cluster subpopulations. Second, we have explored the rotational signature and velocity dispersion of the galaxy's halo using over 560 globular clusters with radial velocity measurements. We have also compared the dependence of these properties on galactocentric distance and globular cluster age and metallicity. Using globular clusters as tracer objects, we have analyzed the mass, and mass-to-light ratio of NGC 5128. Last, we have measured the structural parameters, such as half-light radii, of over 570 globular clusters from a superb 1.2-square-degree Magellan/IMACS image. We will present the findings of these studies and discuss the connection to the formation and evolution of NGC 5128.

The emission nebula around the subdwarf B (sdB) star PHL 932 is currently classified as a planetary nebula (PN) in the literature. Based on a large body of multi-wavelength data, both new and previously published, we show here that this low-excitation nebula is in fact a small Strömgren sphere (Hii region) in the interstellar medium around this star. We summarise the properties of the nebula and its ionizing star, and discuss its evolutionary status. We find no compelling evidence for close binarity, arguing that PHL 932 is an ordinary sdB star. We also find that the emission nebulae around the hot DO stars PG 0108 + 101 and PG 0109 + 111 are also Strömgren spheres in the ISM, and along with PHL 932, are probably associated with the same extensive region of high-latitude molecular gas in Pisces–Pegasus.

The Square Kilometre Array (SKA) provides an excellent opportunity for low-cost searches for fast radio transients. The increased sensitivity and field of view of the SKA compared with other radio telescopes will make it an ideal instrument to search for impulsive emission from high–energy density events. We present a high-level search ‘use case’ and propose event rate per unit cost as a figure of merit to compare transient survey strategies for radio telescope arrays; we use event rate per beam formed and searched as a first-order approximation of this measure. Key results are that incoherent (phase-insensitive) combination of antenna signals achieves the highest event rate per beam, and that 50–100 MHz processed bandwidth is sufficient for extragalactic searches with SKA Phase 1; the gain in event rate from using the full available bandwidth is small. Greater system flexibility will enable more effective searches, but need not drive the top-level system requirements beyond those already proposed for the SKA. The most appropriate search strategy depends on the observed sky direction and the source population; for SKA Phase 1, low-frequency aperture arrays tend to be more effective for extragalactic searches, and dishes more effective for directions of increased scatter broadening, such as near the Galactic plane.

We report on a concerted effort aimed at understanding the origin and history of the pre-solar nanodiamonds in meteorites including the astrophysical sources of the observed isotopic abundance signatures. This includes measurement of light elements by secondary ion mass spectrometry (SIMS), analysis of additional heavy trace elements by accelerator mass spectrometry (AMS) and dynamic calculations of r-process nucleosynthesis with updated nuclear properties. Results obtained indicate that: (i) there is no evidence for the former presence of now-extinct 26Al and 44Ti in our diamond samples other than what can be attributed to silicon carbide and other ‘impurities’, and this does not offer support for a supernova (SN) origin but neither does it negate it; (ii) analysis by AMS of platinum in ‘bulk diamond’ yields an overabundance of r-only 198Pt that at face value seems more consistent with the neutron burst than with the separation model for the origin of heavy trace elements in the diamonds, although this conclusion is not firm given analytical uncertainties; (iii) if the Xe–H pattern was established by an unadulterated r-process, it must have been a strong variant of the main r-process, which possibly could also account for the new observations in platinum.

Expanding upon Pimbblet's 2011 analysis of career h-indices for members of the Astronomical Society of Australia, we provide additional citation metrics which are geared to quantifying the current performance of all professional astronomers in Australia. We have trawled the staff web-pages of Australian Universities, Observatories and Research Organisations hosting professional astronomers, and identified 384 PhD-qualified, research-active, astronomers in the nation. 132 of these are not members of the Astronomical Society of Australia. Using the SAO/NASA Astrophysics Data System, we provide the three following common metrics based on publications in the first decade of the 21st century (2001–2010): h-index, author-normalised citation count and lead-author citation count. We additionally present a somewhat more inclusive analysis, applicable for many early-career researchers, that is based on publications from 2006–2010. Histograms and percentiles, plus top-performer lists, are presented for each category. Finally, building on Hirsch's empirical equation, we find that the (10-year) h-index and (10-year) total citation count T can be approximated by the relation h (0.5 + √T)/√5 for h ≳ 5.

The gas added to and removed from galaxies over cosmic time greatly affects their stellar populations and star formation rates. QSO absorption line studies in close QSO/galaxy pairs create a unique opportunity to study the physical conditions and kinematics of this gas. Here we present new Hubble Space Telescope (HST) images of the QSO/galaxy pair, 3C 232/NGC 3067. The quasar spectrum contains a Lyman limit (NHi = 1 × 1020 cm−2) absorption system (LLS) at cz = 1421 km s−1 that is associated with the nearby Sab galaxy NGC 3067. Previous work identifies this absorber as a high-velocity cloud (HVC) in NGC 3067 but the kinematics of the absorbing gas, infalling or outflowing, were uncertain. The HST images presented here establish the orientation of NGC 3067 and so establish that the LLS/HVC is infalling. Using this system as a prototype, we extend these results to higher-z MgII/LLS to suggest that Mgii/LLSs are a sightline sampling of the so-called ‘cold mode accretion’ (CMA) infalling onto luminous galaxies. To match the observed MgII absorber statistics, the CMA must be more highly ionised at higher redshifts. The key observations needed to further the study of low-z LLSs is HST UV spectroscopy, for which a new instrument, the Cosmic Origins Spectrograph, has just been installed greatly enhancing our observational capabilities.

The current standard model of cosmology (SMoC) requires The Dual Dwarf Galaxy Theorem to be true according to which two types of dwarf galaxies must exist: primordial dark-matter (DM) dominated (type A) dwarf galaxies, and tidal-dwarf and ram-pressure-dwarf (type B) galaxies void of DM. Type A dwarfs surround the host approximately spherically, while type B dwarfs are typically correlated in phasespace. Type B dwarfs must exist in any cosmological theory in which galaxies interact. Only one type of dwarf galaxy is observed to exist on the baryonic Tully-Fisher plot and in the radius-mass plane. The Milky Way satellite system forms a vast phase-space-correlated structure that includes globular clusters and stellar and gaseous streams. Other galaxies also have phase-space correlated satellite systems. Therefore, The Dual Dwarf Galaxy Theorem is falsified by observation and dynamically relevant cold or warm DM cannot exist. It is shown that the SMoC is incompatible with a large set of other extragalactic observations. Other theoretical solutions to cosmological observations exist. In particular, alone the empirical mass-discrepancy—acceleration correlation constitutes convincing evidence that galactic-scale dynamics must be Milgromian. Major problems with inflationary big bang cosmologies remain unresolved.

The fraction (fesc) of ionizing photons that escape their host galaxy and so are able to ionize hydrogen in the intergalactic medium is a critical parameter in studies of the reionization era. In this paper we constrain fesc at high redshift by modelling the observed Lyα transmission. Using an N-body simulation of the cosmic web, we first model an ionizing background due to star-bursting galaxies. We then extract an ensemble of mock absorption spectra from the simulation and compute the mean transmission. We adjust the free parameter, fesc in our model of the ionizing background to reproduce the observed transmission. We find that fesc increases with the minimum galaxy mass considered to contribute to the ionizing background, and that at high redshift fesc must be greater than 5% irrespective of galaxy mass. Based on our numerical results we calibrate a semi-analytic model which shows that the ionizing background observed at z ∼ 5.5–6 implies a sufficient number of ionizing photons to have reionized the Universe by z ∼ 6. However, if the minimum mass for star-formation were ≳109 M⊙, the ionizing background would be over-produced at z ≲ 5. In summary, our results indicate that the Universe was reionized by low mass galaxies.

The Hirsch h-index is now widely used as a metric to compare individual researchers. To evaluate it in the context of Australian astronomy, the h-index for every member of the Astronomical Society of Australia (ASA) is found using NASA's Astrophysics Data System Bibliographic Services. Percentiles of the h-index distribution are detailed for a variety of categories of ASA members, including students. This enables a list of the top ten Australian researchers by h-index to be produced. These top researchers have h-index values in the range 53<h<77, which is less than that recently reported for the American Astronomical Society membership. We suggest that membership of extremely large consortia such as the Sloan Digital Sky Survey may partially explain the difference. We further suggest that many student ASA members with large h-index values have probably already received their Ph.D. and need to upgrade their ASA membership status. To attempt to specify the h-index distribution relative to opportunity, we also detail the percentiles of its distribution by years since Ph.D. award date. This shows a steady increase in h-index with seniority, as can be expected.

We present infrared imaging from IRIS2 on the Anglo–Australian Telescope that shows the barred spiral galaxy IC 4933 has not just an inner ring encircling the bar, but also a star-forming nuclear ring 1.5 kpc in diameter. Imaging in the u′ band with GMOS on Gemini South confirms that this ring is not purely an artifact due to dust. Optical and near-infrared colours alone however cannot break the degeneracy between age, extinction, and burst duration that would allow the star formation history of the ring to be unraveled. Integral field spectroscopy with the GNIRS spectrograph on Gemini South shows the equivalent width of the Paβ line to peak in the north and south quadrants of the ring, indicative of a bipolar azimuthal age gradient around the ring. The youngest star-forming regions do not appear to correspond to where we expect to find the contact points between the offset dust lanes and the nuclear ring unless the nuclear ring is oval in shape, causing the contact points to lead the bar by more than 90°.