We report here on two years of timing of 168 pulsars using the Parkes radio telescope. The vast majority of these pulsars have spin-down luminosities in excess of 1034 erg s−1 and are prime target candidates to be detected in gamma-rays by the Fermi Gamma-Ray Space Telescope. We provide the ephemerides for the ten pulsars being timed at Parkes which have been detected by Fermi in its first year of operation. These ephemerides, in conjunction with the publicly available photonlist, can be used to generate gamma-ray profiles from the Fermi archive. We will make the ephemerides of any pulsars of interest available to the community upon request. In addition to the timing ephemerides, we present the parameters for 14 glitches which have occurred in 13 pulsars, seven of which have no previously known glitch history.The Parkes timing programme, in conjunction with Fermi observations, is expected to continue for at least the next four years.

We review the importance of Centaurus A in high-energy astrophysics as a nearby object with many of the properties expected of a major source of very high-energy cosmic rays and gamma rays. We examine observational techniques and the results so far obtained in the energy range from 200 GeV to above 100 EeV and attempt to fit those data to expectations of Centaurus Aas an astrophysical source from very high to ultra-high energies.

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.

We present the results of the search for candidate Planetary Nebulae interacting with the interstellar medium (PN–ISM) in the framework of the INT Photometric Hα Survey (IPHAS) and located in the right ascension range 18–20 h. The detection capability of this new Northern survey, in terms of depth and imaging resolution, has allowed us to overcome the detection problem generally associated to the low surface brightness inherent to PNe-ISM. We discuss the detection of 21 IPHAS PN–ISM candidates. Thus, different stages of interaction were observed, implying various morphologies i.e. from the unaffected to totally disrupted shapes. The majority of the sources belong to the so-called WZO2 stage which main characteristic is a brightening of the nebula's shell in the direction of motion. The new findings are encouraging as they would be a first step into the reduction of the scarcity of observational data and they would provide new insights into the physical processes occurring in the rather evolved PNe.

We are developing a purely commensal survey experiment for fast (<5 s) transient radio sources. Short-timescale transients are associated with the most energetic and brightest single events in the Universe. Our objective is to cover the enormous volume of transients parameter space made available by ASKAP, with an unprecedented combination of sensitivity and field of view. Fast timescale transients open new vistas on the physics of high brightness temperature emission, extreme states of matter and the physics of strong gravitational fields. In addition, the detection of extragalactic objects affords us an entirely new and extremely sensitive probe on the huge reservoir of baryons present in the IGM. We outline here our approach to the considerable challenge involved in detecting fast transients, particularly the development of hardware fast enough to dedisperse and search the ASKAP data stream at or near real-time rates. Through CRAFT, ASKAP will provide the testbed of many of the key technologies and survey modes proposed for high time resolution science with the SKA.

Since various structural components of planetary nebulae (PN) manifest themselves differently, a combination of optical, infrared, submillimetre and radio techniques is needed to derive a complete picture of planetary nebulae. The effects of projection can also make derivation of the true 3-D structure difficult. Using a number of examples, we show that bipolar and multipolar nebulae are much more common than usually inferred from morphological classifications of apparent structures of planetary nebulae. We put forward a new hypothesis that the bipolar and multipolar lobes of PN are not regions of high-density ejected matter, but the result of ionization and illumination. The visible bright regions are in fact volumes of low density (cleared by high-velocity outflows), through which UV photons are being channelled. We suggest that multipolar nebulae with similar lobe sizes are not caused by simultaneous ejection of matter in several directions, but by leakage of UV photons in those directions.

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.

At less than 4 Mpc distance the radio galaxy NGC 5128 (Centaurus A) is the prime example to study the supermassive black hole and its influence on the environment in great detail. To model and understand the feeding and feedback mechanisms one needs an accurate determination of the mass of the supermassive black hole. The aim of this review is to give an overview of the recent studies that have been dedicated to measure the black hole mass in Centaurus A from both gas and stellar kinematics. It shows how the advancement in observing techniques and instrumentation drive the field of black hole mass measurements and concludes that adaptive optics assisted integral field spectroscopy is the key to identify the effects of the AGN on the surrounding ionised gas. Using data from SINFONI at the ESO Very Large Telescope, the best-fit black hole mass is MBH = 4.5(+1.7, −1.0) × 107 M⊙ (from H2 kinematics) and MBH = (5.5 ± 3.0) × 107 M⊙ (from stellar kinematics). This is one of the cleanest gas-versus-star comparisons of a MBH determination, and brings Centaurus A into agreement with the MBH−σ relation.

We report an optimal extraction methodology, for the reduction of multi-object fibre spectroscopy data, operating in the regime of tightly packed (and hence significantly overlapping) fibre profiles. The routine minimises crosstalk between adjacent fibres and statistically weights the extraction to reduce noise. As an example of the process we use simulations of the numerous modes of operation of the AAOmega fibre spectrograph and observational data from the SPIRAL Integral Field Unit at the Anglo-Australian Telescope.

Planetary nebulae (PNe) can be roughly categorized into several broad morphological classes. The high quality images of PNe acquired in recent years, however, have revealed a wealth of fine structures that preclude simplistic models for their formation. Here we present narrow-band, sub-arcsecond images of a sample of relatively large PNe that illustrate the complexity and variety of small-scale structures. This is especially true for bipolar PNe, for which the images reveal multi-polar ejections and, in some cases, suggest turbulent gas motions. Our images also reveal the presence or signs of jet-like outflows in several objects in which this kind of component has not been previously reported.

An all-sky comprehensive catalogue of calculated radio and X-ray associations to optical objects is presented. Included are X-ray sources from XMM-Newton, Chandra and ROSAT catalogues, radio sources from NVSS, FIRST and SUMSS catalogues, and optical data, identifications and redshifts from the APM, USNO-A, SDSS-DR7 and the extant literature. This ‘Atlas of Radio/X-ray Associations’ inherits many techniques from the predecessor Quasars.org (2004) catalogue, but object selection is changed and processing tweaked. Optical objects presented are those which are calculated with ≥40% confidence to be associated with radio/X-ray detections, totalling 602 570 objects in all, including 23 681 double radio lobe detections. For each of these optical objects I display the calculated percentage probabilities of its being a QSO, galaxy, star, or erroneous radio/X-ray association, plus any identification from the literature. The catalogue includes 105 568 uninvestigated objects listed as 40% to >99% likely to be a QSO. The catalogue is available at http://quasars.org/arxa.htm.

In this paper we review the various high precision methods that are now available to determine the distance to NGC 5128. These methods include: Cepheids, TRGB (tip of the red giant branch), PNLF (planetary nebula luminosity function), SBF (surface brightness fluctuations), and Long Period Variable (LPV) Mira stars. From an evaluation of these methods and their uncertainties, we derive a best-estimate distance of 3.8±0.1 Mpc to NGC 5128 and find that this mean is now well supported by the current data. We also discuss the role of NGC 5128 more generally for the extragalactic distance scale as a testbed for the most direct possible comparison among these key methods.

Centaurus A (NGC 5128) is ideal for investigating the characteristics and role of gas in an earlytype galaxy in the presence of a radio-loud active nucleus. The different phases of the gas—hot (X-ray), warm (ionized), and cold (H i and molecular)—are all detected in this object and can be studied at very high spatial resolution, due to its proximity. This richness makes Centaurus A truly unique. Spatially, these gas structures span from the pc to the tens of kpc scale. Thus, they allow us to trace very different phenomena, from the formation and evolution of the host galaxy, to the interplay between nuclear activity and interstellar medium and the feeding mechanism of the central black hole. A lot of work has been done to study and understand the characteristics of the gas in this complex object, and the present paper summarizes what has been achieved so far.

A fibre spectrum profile fitting method based on the least-squares method is presented in this article. For each spectrum of one fibre in spatial orientation, two exponential functions are employed to approximate the profile. Experiments are performed with both simulated profiles and observed profiles to demonstrate the effectiveness of the algorithm. Specially, the proposed method has a better performance for profiles that are asymmetric or composed of multi-Gaussian functions.

This paper defines the mathematical convention adopted to describe an electromagnetic wave and its polarisation state, as implemented in the psrchive software and represented in the psrfits definition. Contrast is made between the convention that has been widely accepted by pulsar astronomers and the IAU/IEEE definitions of the Stokes parameters. The former is adopted as the PSR/IEEE convention, and a set of useful parameters are presented for describing the differences between the PSR/IEEE standard and the conventions (either implicit or explicit) that form part of the design of observatory instrumentation. To aid in the empirical determination of instrumental convention parameters, well-calibrated average polarisation profiles of PSR J0304+1932 and PSR J0742–2822 are presented at radio wavelengths of approximately 10, 20, and 40 cm.

The three main methods currently in use for estimating the excitation class of planetary nebulae (PNe) central stars are compared and evaluated using 586 newly discovered and previously known PNe in the Large Magellanic Cloud (LMC). In order to achieve this we ran a series of evaluation tests using line ratios derived from de-reddened, flux-calibrated spectra. Pronounced differences between the methods are exposed after comparing the distribution of objects to their derived excitation. Line ratio comparisons show that each method's input parameters have a strong effect on the estimated excitation of a central star. Diagrams were created by comparing excitation classes with Hβ line fluxes. The best methods are then compared to published temperatures using the Zanstra method and assessed for their ability to reflect central star effective temperatures and evolution. As a result we call for a clarification of the term ‘excitation class’ according to the different input parameters used. The first method, which we refer to as Exneb relies purely on the ratios of certain key emission lines. The second method, which we refer to as Ex* includes modeling to create a continuous variable and, for optically thick PNe in the Magellanic Clouds, is designed to relate more closely to intrinsic stellar parameters. The third method, we refer to as Ex[Oiii]/Hβ since the [Oiii]/Hβ ratio is used in isolation to other temperature diagnostics. Each of these methods is shown to have serious drawbacks when used as an indicator for central star temperature. Finally, we suggest a new method (Exρ) for estimating excitation class incorporating both the [Oiii]/Hβ and the HeII λ4686/Hβ ratios. Although any attempt to provide accurate central star temperatures using the excitation class derived from nebula lines will always be limited, we show that this new method provides a substantial improvement over previous methods with better agreement to temperatures derived through the Zanstra method.

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.

We have recently confirmed the planetary nebula (PN) nature of PM 1–242, PM 1–318 and PM 1–322. Here we present high-resolution long-slit spectra of these three PNe in order to analyze their internal kinematics and to investigate their physical structure. PM 1–242 is a tilted ring and not an elliptical PN as suggested by direct images. The object is probably related to ring-like PNe and shows an unusual pointsymmetric brightness distribution in the ring. PM 1–318 is a pole-on elliptical PN, instead of a circular one as suggested by direct images. PM 1–322 is spatially unresolved and its spectrum shows large differences between the forbidden lines and Hα profiles, with the latter showing a double-peaked profile and relatively extended wings (FWZI ~325 km s−1). These properties are found in other PNe that are suspected to host a symbiotic central star.

S5 0716+714 is a well-studied BL Lac object in the sky. Verifying the existence of correlations among the flux variations in different bands serves as an important tool to investigate the emission processes. To examine the possible existence of a lag between variations in different optical bands on this source, we employ a discrete correlation function analysis on the light curves. In order to obtain statistically meaningful values for the cross-correlation time lags and their related uncertainties, we perform Monte Carlo simulations called ‘flux redistribution/random subset selection’. Our analysis confirms that the variations in different optical light curves are strongly correlated. The time lags show a hint of the variations in high frequency band leading those in low frequency band of the order of a few minutes.

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.