After the SKA - Radio Astronomy in 2049

The concept of a Square Kilometre Array was developed to ensure that progress in Radio Astronomy in the early 21st Century continued at the same impressive pace as was achieved during the first 50 years. The SKA telescope is designed to pave that road to greater and greater sensitivity. So what technical challenges does the project face and what key innovations will drive the success of the SKA? What will the next Radio Astronomy mega-science project look like? In this article the author discusses the likely avenues of progress in the coming decades and comments on the status of radio astronomy in 2049 - the author's 70th (and presumably her retirement) year.Comment: Conference Proceedings PoS(RTS2012), 8 pages, 1 figur

Promoting equity in STEM classrooms

This keynote, delivered by Professor Lisa Harvey-Smith, will outline the current state of play for women and girls’ participation in STEM, and consider how staff in universities can contribute to achieving greater equity in STEM subjects. Professor Harvey-Smith is the Australian Government’s Women in STEM Ambassador and a Professor of Practice at the University of New South Wales. In her role, Lisa and her team work to cultivate the conditions in which all Australians can pursue successful and rewarding careers in STEM. The work of the Ambassador’s Office includes: providing expert advice to policy makers, peak bodies, and other stakeholders; education and outreach through the Future You national awareness raising initiative; as well as contributing to current research into equitable STEM participation and evidence-based practices to improve participation, engagement and outcomes for diverse students

One year of monitoring the Vela pulsar using a Phased Array Feed

We have observed the Vela pulsar for one year using a Phased Array Feed (PAF) receiver on the 12-metre antenna of the Parkes Test-Bed Facility. These observations have allowed us to investigate the stability of the PAF beam-weights over time, to demonstrate that pulsars can be timed over long periods using PAF technology and to detect and study the most recent glitch event that occurred on 12 December 2016. The beam-weights are shown to be stable to 1% on time scales on the order of three weeks. We discuss the implications of this for monitoring pulsars using PAFs on single dish telescopes.Comment: 6 pages, 4 figures, 2 tables. Accepted for publication in PAS

The Water Maser in MG 0414+0534: The Influence of Gravitational Microlensing

Water masers have been observed in several high redshift active galactic nuclei, including the gravitationally lensed quasar MG 0414+0534. This quasar is lensed into four images, and the water maser is detected in two of them. The broadening of the maser emission line and its velocity offset are consistent with a group of masers associated with a quasar jet. If the maser group is microlensed we can probe its structure and size by observing its microlensing behaviour over time. We present results of a high resolution numerical analysis of microlensing of the maser in MG 0414+0534, using several physically motivated maser models covering a range of sizes and emission profiles. Time-varying spectra of the microlensed maser are generated, displayed, and analysed, and the behaviour of the different models compared. The observed maser line in MG 0414+0534 is consistent with maser spots as in other quasar jets, provided substructure is de-magnified or currently lost in noise; otherwise smooth extended maser models are also candidates to generate the observed spectrum. Using measures of spectral variability we find that if the maser has small substructure of ~ 0.002 pc then a variation of 0.12 mag in flux and 2.0 km/s in velocity centroid of the maser line could be observed within 2 decades. For the smallest maser model in this study a magnification of > 35 is possible 22% of the time, which is of significance in the search for other lensed masers.Comment: 13 pages, 7 low-quality figures, 1 table, accepted for MNRA

The Nature of the Stingray Nebula from Radio Observations

We have analysed the full suite of Australia Telescope Compact Array data for the Stingray planetary nebula. Data were taken in the 4- to 23-GHz range of radio frequencies between 1991 and 2016. The radio flux density of the nebula generally declined during that period, but between 2013 and 2016 it shows signs of halting that decline. We produced the first spatially resolved radio images of the Stingray nebula from data taken in 2005. A ring structure, which appears to be associated with the ring seen in HST images, was visible. In addition, we found a narrow extension to the radio emission towards the eastern and western edges of the nebula. We derived the emission measure of the nebula - this decreased between 1992 and 2011, suggesting that the nebula is undergoing recombination. The radio spectral index is broadly consistent with a free-free emission mechanism, however a single data point hints that a steeper spectral index has possibly emerged since 2013, which could indicate the presence of synchrotron emission. If a non-thermal component component has emerged, such as one associated with a region that is launching a jet or outflow, we predict that it would intensify in the years to come.Comment: Accepted to MNRAS. 9 pages, 6 figure

A template for resource productivity/sustainability programs in forest products manufacturing facilities

53 p.This document introduces the principles and practices of resource productivity and sustainable development as they may apply to forest products manufacturing firms and facilities. It was developed by a group of forest products professionals with staffing assistance from the Center for Watershed and Community Health at Portland State University. This is a working draft, and the authors request feedback on content, presentation and usefulness. Part I of the document provides background information on resource productivity and sustainability. It is intended to prepare the reader to use the template outlined in Part II. The template is organized around the steps involved with answering the five key questions that should drive the development of your resource productivity/sustainability program

Estimating extragalactic Faraday rotation

(abridged) Observations of Faraday rotation for extragalactic sources probe magnetic fields both inside and outside the Milky Way. Building on our earlier estimate of the Galactic contribution, we set out to estimate the extragalactic contributions. We discuss the problems involved; in particular, we point out that taking the difference between the observed values and the Galactic foreground reconstruction is not a good estimate for the extragalactic contributions. We point out a degeneracy between the contributions to the observed values due to extragalactic magnetic fields and observational noise and comment on the dangers of over-interpreting an estimate without taking into account its uncertainty information. To overcome these difficulties, we develop an extended reconstruction algorithm based on the assumption that the observational uncertainties are accurately described for a subset of the data, which can overcome the degeneracy with the extragalactic contributions. We present a probabilistic derivation of the algorithm and demonstrate its performance using a simulation, yielding a high quality reconstruction of the Galactic Faraday rotation foreground, a precise estimate of the typical extragalactic contribution, and a well-defined probabilistic description of the extragalactic contribution for each data point. We then apply this reconstruction technique to a catalog of Faraday rotation observations. We vary our assumptions about the data, showing that the dispersion of extragalactic contributions to observed Faraday depths is most likely lower than 7 rad/m^2, in agreement with earlier results, and that the extragalactic contribution to an individual data point is poorly constrained by the data in most cases.Comment: 20 + 6 pages, 19 figures; minor changes after bug-fix; version accepted for publication by A&A; results are available at http://www.mpa-garching.mpg.de/ift/faraday

MAGMO: polarimetry of 1720-MHz OH masers towards southern star-forming regions

From targeted observations of ground-state hydroxyl (OH) masers towards 702 Methanol Multibeam survey 6.7-GHz methanol masers, in the Galactic longitude range from 186 degrees C through the Galactic Centre to 20 degrees C, made as part of the 'MAGMO' (Mapping the Galactic Magnetic field through OH masers) project, we present the physical and polarization properties of the 1720-MHz OH maser transition, including the identification of Zeeman pairs. We present 10 new and 23 previously catalogued 1720-MHz OH maser sources detected towards star-forming regions (SFRs). In addition, we also detected 16 1720-MHz OH masers associated with supernova remnants and two sites of diffuse OH emission. Towards the 33 star formation masers, we identify 44 Zeeman pairs, implying magnetic field strengths ranging from −11.4 to +13.2 mG, and a median magnetic field strength of |BLOS| ∼ 6 mG. With limited statistics, we present the in situ magnetic field orientation of the masers and the Galactic magnetic field distribution revealed by the 1720-MHz transition. We also examine the association statistics of 1720-MHz OH SFR masers with other ground-state OH masers, excited-state OH masers, class I and class II methanol masers, and water masers, and compare maser positions with mid-infrared images of the parent SFRs. Of the 33 1720-MHz star formation masers, 10 are offset from their central exciting sources, and appear to be associated with outflow activity.This work was presented as part of CSO’s doctoral program funded by the International Macquarie Research Excellence Scholarship (iMQRES) program. CSO was also a recipient of the Commonwealth Scientific and Industrial Research Organisation (CSIRO) Astronomy and Space Science Student Program grant for which CSO is grateful. JRD acknowledges the support of an Australian Research Council (ARC) DECRA Fellowship (project number DE170101086). This paper includes archived data obtained through the Australia Telescope Online Archive (http://atoa.atnf.csiro.au). The Australia Telescope Compact Array (ATCA) is part of the Australia Telescope National Facility and funded by the CSIRO. This research made use of APLPY, an open-source plotting package for PYTHON (Robitaille & Bressert 2012)

The extraordinary linear polarisation structure of the southern Centaurus A lobe revealed by ASKAP

We present observations of linear polarisation in the southern radio lobe of Centaurus A, conducted during commissioning of the Australian Square Kilometre Array Pathfinder (ASKAP) telescope. We used 16 antennas to observe a 30 square degree region in a single 12 hour pointing over a 240 MHz band centred on 913 MHz. Our observations achieve an angular resolution of $26\times33$ arcseconds (480 parsecs), a maximum recoverable angular scale of 30 arcminutes, and a full-band sensitivity of 85 \muupJy beam$^{-1}$. The resulting maps of polarisation and Faraday rotation are amongst the most detailed ever made for radio lobes, with of order 10$^5$ resolution elements covering the source. We describe several as-yet unreported observational features of the lobe, including its detailed peak Faraday depth structure, and intricate networks of depolarised filaments. These results demonstrate the exciting capabilities of ASKAP for widefield radio polarimetry.Comment: 10 pages, 6 figures. Accepted in "The Power of Faraday Tomography" special issue of Galaxie