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The MAGPI survey: Science goals, design, observing strategy, early results and theoretical framework
C. Foster, J. T. Mendel, C. D. P. Lagos, E. Wisnioski, T. Yuan, F. D'Eugenio, T. M. Barone, K. E. Harborne, S. P. Vaughan, F. Schulze, R.-S. Remus, A. Gupta, F. Collacchioni, D. J. Khim, P. Taylor, R. Bassett, S. M. Croom, R. M. McDermid, A. Poci, A. J. Battisti, J. Bland-Hawthorn, S. Bellstedt, M. Colless, L. J. M. Davies, C. Derkenne, S. Driver, A. Ferré-Mateu, D. B. Fisher, E. Gjergo, E. J. Johnston, A. Khalid, C. Kobayashi, S. Oh, Y. Peng, A. S. G. Robotham, P. Sharda, S. M. Sweet, E. N. Taylor, K.-V. H. Tran, J. W. Trayford, J. van de Sande, S. K. Yi, L. Zanisi
Published online by Cambridge University Press: 26 July 2021, e031
We present an overview of the Middle Ages Galaxy Properties with Integral Field Spectroscopy (MAGPI) survey, a Large Program on the European Southern Observatory Very Large Telescope. MAGPI is designed to study the physical drivers of galaxy transformation at a lookback time of 3–4 Gyr, during which the dynamical, morphological, and chemical properties of galaxies are predicted to evolve significantly. The survey uses new medium-deep adaptive optics aided Multi-Unit Spectroscopic Explorer (MUSE) observations of fields selected from the Galaxy and Mass Assembly (GAMA) survey, providing a wealth of publicly available ancillary multi-wavelength data. With these data, MAGPI will map the kinematic and chemical properties of stars and ionised gas for a sample of 60 massive ( ${>}7 \times 10^{10} {\mathrm{M}}_\odot$ ) central galaxies at $0.25 < z <0.35$ in a representative range of environments (isolated, groups and clusters). The spatial resolution delivered by MUSE with Ground Layer Adaptive Optics ( $0.6-0.8$ arcsec FWHM) will facilitate a direct comparison with Integral Field Spectroscopy surveys of the nearby Universe, such as SAMI and MaNGA, and at higher redshifts using adaptive optics, for example, SINS. In addition to the primary (central) galaxy sample, MAGPI will deliver resolved and unresolved spectra for as many as 150 satellite galaxies at $0.25 < z <0.35$ , as well as hundreds of emission-line sources at $z < 6$ . This paper outlines the science goals, survey design, and observing strategy of MAGPI. We also present a first look at the MAGPI data, and the theoretical framework to which MAGPI data will be compared using the current generation of cosmological hydrodynamical simulations including EAGLE, Magneticum, HORIZON-AGN, and Illustris-TNG. Our results show that cosmological hydrodynamical simulations make discrepant predictions in the spatially resolved properties of galaxies at $z\approx 0.3$ . MAGPI observations will place new constraints and allow for tangible improvements in galaxy formation theory.
Statistical analysis of fireballs: Seismic signature survey
T. Neidhart, K. Miljković, E. K. Sansom, H. A. R. Devillepoix, T. Kawamura, J.-L. Dimech, M. A. Wieczorek, P. A. Bland
Published online by Cambridge University Press: 15 April 2021, e016
Fireballs are infrequently recorded by seismic sensors on the ground. If recorded, they are usually reported as one-off events. This study is the first seismic bulk analysis of the largest single fireball data set, observed by the Desert Fireball Network (DFN) in Australia in the period 2014–2019. The DFN typically observes fireballs from cm-m scale impactors. We identified 25 fireballs in seismic time series data recorded by the Australian National Seismograph Network (ANSN). This corresponds to 1.8% of surveyed fireballs, at the kinetic energy range of $10^6$ – $10^{10}$ J. The peaks observed in the seismic time series data were consistent with calculated arrival times of the direct airwave or ground-coupled Rayleigh wave caused by shock waves by the fireball in the atmosphere (either due to fragmentation or the passage of the Mach cone). Our work suggests that identification of fireball events in the seismic time series data depends on both physical properties of a fireball (such as fireball energy and entry angle in the atmosphere) and the sensitivity of a seismic instrument. This work suggests that fireballs are likely detectable within 200 km direct air distance between a fireball and seismic station, for sensors used in the ANSN. If each DFN observatory had been accompanied by a seismic sensor of similar sensitivity, 50% of surveyed fireballs could have been detected. These statistics justify the future consideration of expanding the DFN camera network into the seismic domain.
Novel method of calculating adjusted antibiotic use by microbiological burden
Hana R. Winders, Majdi N. Al-Hasan, Bruce M. Jones, Darrell T. Childress, Kayla R. Stover, Benjamin B. Britt, Elias B. Chahine, Suetping Lau, Pamela D. Andrews, Shauna Jacobson Junco, Rebekah H. Wrenn, Brad J. Crane, Jordan R. Wong, Megan M. Seddon, Christopher M. Bland, Shawn H. MacVane, Geneen M. Gibson, P. Brandon Bookstaver
Journal: Infection Control & Hospital Epidemiology / Volume 42 / Issue 6 / June 2021
Published online by Cambridge University Press: 28 January 2021, pp. 688-693
Print publication: June 2021
To determine the usefulness of adjusting antibiotic use (AU) by prevalence of bacterial isolates as an alternative method for risk adjustment beyond hospital characteristics.
Retrospective, observational, cross-sectional study.
Hospitals in the southeastern United States.
AU in days of therapy per 1,000 patient days and microbiologic data from 2015 and 2016 were collected from 26 hospitals. The prevalences of Pseudomonas aeruginosa, extended-spectrum β-lactamase (ESBL)–producing bacteria, methicillin-resistant Staphylococcus aureus (MRSA), and vancomycin-resistant enterococci (VRE) were calculated and compared to the average prevalence of all hospitals in the network. This proportion was used to calculate the adjusted AU (a-AU) for various categories of antimicrobials. For example, a-AU of antipseudomonal β-lactams (APBL) was the AU of APBL divided by (prevalence of P. aeruginosa at that hospital divided by the average prevalence of P. aeruginosa). Hospitals were categorized by bed size and ranked by AU and a-AU, and the rankings were compared.
Most hospitals in 2015 and 2016, respectively, moved ≥2 positions in the ranking using a-AU of APBL (15 of 24, 63%; 22 of 26, 85%), carbapenems (14 of 23, 61%; 22 of 25; 88%), anti-MRSA agents (13 of 23, 57%; 18 of 26, 69%), and anti-VRE agents (18 of 24, 75%; 15 of 26, 58%). Use of a-AU resulted in a shift in quartile of hospital ranking for 50% of APBL agents, 57% of carbapenems, 35% of anti-MRSA agents, and 75% of anti-VRE agents in 2015 and 50% of APBL agents, 28% of carbapenems, 50% of anti-MRSA agents, and 58% of anti-VRE agents in 2016.
The a-AU considerably changes how hospitals compare among each other within a network. Adjusting AU by microbiological burden allows for a more balanced comparison among hospitals with variable baseline rates of resistant bacteria.
Recreating the OSIRIS-REx slingshot manoeuvre from a network of ground-based sensors
Trent Jansen-Sturgeon, Benjamin A. D. Hartig, Gregory J. Madsen, Philip A. Bland, Eleanor K. Sansom, Hadrien A. R. Devillepoix, Robert M. Howie, Martin Cupák, Martin C. Towner, Morgan A. Cox, Nicole D. Nevill, Zacchary N. P. Hoskins, Geoffrey P. Bonning, Josh Calcino, Jake T. Clark, Bryce M. Henson, Andrew Langendam, Samuel J. Matthews, Terence P. McClafferty, Jennifer T. Mitchell, Craig J. O'Neill, Luke T. Smith, Alastair W. Tait
Published online by Cambridge University Press: 27 November 2020, e049
Optical tracking systems typically trade off between astrometric precision and field of view. In this work, we showcase a networked approach to optical tracking using very wide field-of-view imagers that have relatively low astrometric precision on the scheduled OSIRIS-REx slingshot manoeuvre around Earth on 22 Sep 2017. As part of a trajectory designed to get OSIRIS-REx to NEO 101955 Bennu, this flyby event was viewed from 13 remote sensors spread across Australia and New Zealand to promote triangulatable observations. Each observatory in this portable network was constructed to be as lightweight and portable as possible, with hardware based off the successful design of the Desert Fireball Network. Over a 4-h collection window, we gathered 15 439 images of the night sky in the predicted direction of the OSIRIS-REx spacecraft. Using a specially developed streak detection and orbit determination data pipeline, we detected 2 090 line-of-sight observations. Our fitted orbit was determined to be within about 10 km of orbital telemetry along the observed 109 262 km length of OSIRIS-REx trajectory, and thus demonstrating the impressive capability of a networked approach to Space Surveillance and Tracking.
COVID-19 induced social isolation; implications for understanding social cognition in mental health
A. R. Bland, J. P .Roiser, M. A. Mehta, B. J. Sahakian, T. W. Robbins, R. Elliott
Journal: Psychological Medicine , First View
Published online by Cambridge University Press: 08 October 2020, pp. 1-2
ASKAP commissioning observations of the GAMA 23 field
Australian SKA Pathfinder
Denis A. Leahy, A. M. Hopkins, R. P. Norris, J. Marvil, J. D. Collier, E. N. Taylor, J. R. Allison, C. Anderson, M. Bell, M. Bilicki, J. Bland-Hawthorn, S. Brough, M. J. I. Brown, S. Driver, G. Gurkan, L. Harvey-Smith, I. Heywood, B. W. Holwerda, J. Liske, A. R. Lopez-Sanchez, D. McConnell, A. Moffett, M. S. Owers, K. A. Pimbblet, W. Raja, N. Seymour, M. A. Voronkov, L. Wang
We have observed the G23 field of the Galaxy AndMass Assembly (GAMA) survey using the Australian Square Kilometre Array Pathfinder (ASKAP) in its commissioning phase to validate the performance of the telescope and to characterise the detected galaxy populations. This observation covers ~48 deg2 with synthesised beam of 32.7 arcsec by 17.8 arcsec at 936MHz, and ~39 deg2 with synthesised beam of 15.8 arcsec by 12.0 arcsec at 1320MHz. At both frequencies, the root-mean-square (r.m.s.) noise is ~0.1 mJy/beam. We combine these radio observations with the GAMA galaxy data, which includes spectroscopy of galaxies that are i-band selected with a magnitude limit of 19.2. Wide-field Infrared Survey Explorer (WISE) infrared (IR) photometry is used to determine which galaxies host an active galactic nucleus (AGN). In properties including source counts, mass distributions, and IR versus radio luminosity relation, the ASKAP-detected radio sources behave as expected. Radio galaxies have higher stellar mass and luminosity in IR, optical, and UV than other galaxies. We apply optical and IR AGN diagnostics and find that they disagree for ~30% of the galaxies in our sample. We suggest possible causes for the disagreement. Some cases can be explained by optical extinction of the AGN, but for more than half of the cases we do not find a clear explanation. Radio sources aremore likely (~6%) to have an AGN than radio quiet galaxies (~1%), but the majority of AGN are not detected in radio at this sensitivity.
Chapter 4 - Planetary Surface Processes
By Philip A. Bland, Susanne P. Schwenzer
Edited by David A. Rothery, The Open University, Milton Keynes, Neil McBride, The Open University, Milton Keynes, Iain Gilmour, The Open University, Milton Keynes
Book: An Introduction to the Solar System
The Taipan Galaxy Survey: Scientific Goals and Observing Strategy
Elisabete da Cunha, Andrew M. Hopkins, Matthew Colless, Edward N. Taylor, Chris Blake, Cullan Howlett, Christina Magoulas, John R. Lucey, Claudia Lagos, Kyler Kuehn, Yjan Gordon, Dilyar Barat, Fuyan Bian, Christian Wolf, Michael J. Cowley, Marc White, Ixandra Achitouv, Maciej Bilicki, Joss Bland-Hawthorn, Krzysztof Bolejko, Michael J. I. Brown, Rebecca Brown, Julia Bryant, Scott Croom, Tamara M. Davis, Simon P. Driver, Miroslav D. Filipovic, Samuel R. Hinton, Melanie Johnston-Hollitt, D. Heath Jones, Bärbel Koribalski, Dane Kleiner, Jon Lawrence, Nuria Lorente, Jeremy Mould, Matt S. Owers, Kevin Pimbblet, C. G. Tinney, Nicholas F. H. Tothill, Fred Watson
Published online by Cambridge University Press: 24 October 2017, e047
The Taipan galaxy survey (hereafter simply 'Taipan') is a multi-object spectroscopic survey starting in 2017 that will cover 2π steradians over the southern sky (δ ≲ 10°, |b| ≳ 10°), and obtain optical spectra for about two million galaxies out to z < 0.4. Taipan will use the newly refurbished 1.2-m UK Schmidt Telescope at Siding Spring Observatory with the new TAIPAN instrument, which includes an innovative 'Starbugs' positioning system capable of rapidly and simultaneously deploying up to 150 spectroscopic fibres (and up to 300 with a proposed upgrade) over the 6° diameter focal plane, and a purpose-built spectrograph operating in the range from 370 to 870 nm with resolving power R ≳ 2000. The main scientific goals of Taipan are (i) to measure the distance scale of the Universe (primarily governed by the local expansion rate, H 0) to 1% precision, and the growth rate of structure to 5%; (ii) to make the most extensive map yet constructed of the total mass distribution and motions in the local Universe, using peculiar velocities based on improved Fundamental Plane distances, which will enable sensitive tests of gravitational physics; and (iii) to deliver a legacy sample of low-redshift galaxies as a unique laboratory for studying galaxy evolution as a function of dark matter halo and stellar mass and environment. The final survey, which will be completed within 5 yrs, will consist of a complete magnitude-limited sample (i ⩽ 17) of about 1.2 × 106 galaxies supplemented by an extension to higher redshifts and fainter magnitudes (i ⩽ 18.1) of a luminous red galaxy sample of about 0.8 × 106 galaxies. Observations and data processing will be carried out remotely and in a fully automated way, using a purpose-built automated 'virtual observer' software and an automated data reduction pipeline. The Taipan survey is deliberately designed to maximise its legacy value by complementing and enhancing current and planned surveys of the southern sky at wavelengths from the optical to the radio; it will become the primary redshift and optical spectroscopic reference catalogue for the local extragalactic Universe in the southern sky for the coming decade.
Pharmacists' Familiarity with and Institutional Utilization of Rapid Diagnostic Technologies for Antimicrobial Stewardship
Rachel A. Foster, Kristi Kuper, Z. Kevin Lu, P. Brandon Bookstaver, Christopher M. Bland, Monica V. Mahoney
Journal: Infection Control & Hospital Epidemiology / Volume 38 / Issue 7 / July 2017
Print publication: July 2017
Rapid diagnostic technologies (RDTs) significantly reduce organism identification time and can augment antimicrobial stewardship program (ASP) activities. An electronic survey quantified familiarity with and utilization of RDTs by clinical pharmacists participating in ASPs. Familiarity was highest with polymerase chain reaction (PCR). Formal infectious diseases training was the only significant factor influencing RDT familiarity.
Infect Control Hosp Epidemiol 2017;38:863–866
Fast circular dictionary-matching algorithm
TANVER ATHAR, CARL BARTON, WIDMER BLAND, JIA GAO, COSTAS S. ILIOPOULOS, CHANG LIU, SOLON P. PISSIS
Journal: Mathematical Structures in Computer Science / Volume 27 / Issue 2 / February 2017
Print publication: February 2017
Circular string matching is a problem which naturally arises in many contexts. It consists in finding all occurrences of the rotations of a pattern of length m in a text of length n. There exist optimal worst- and average-case algorithms for circular string matching. Here, we present a suboptimal average-case algorithm for circular string matching requiring time $\mathcal{O}$ (n) and space $\mathcal{O}$ (m). The importance of our contribution is underlined by the fact that the proposed algorithm can be easily adapted to deal with circular dictionary matching. In particular, we show how the circular dictionary-matching problem can be solved in average-case time $\mathcal{O}$ (n + M) and space $\mathcal{O}$ (M), where M is the total length of the dictionary patterns, assuming that the shortest pattern is sufficiently long. Moreover, the presented average-case algorithms and other worst-case approaches were also implemented. Experimental results, using real and synthetic data, demonstrate that the implementation of the presented algorithms can accelerate the computations by more than a factor of two compared to the corresponding implementation of other approaches.
Jon D. Levenson. Inheriting Abraham: The Legacy of the Patriarch in Judaism, Christianity, and Islam. Princeton and Oxford: Princeton University Press, 2012. xvi, 244 pp.
Kalman P. Bland
Journal: AJS Review / Volume 37 / Issue 2 / November 2013
Published online by Cambridge University Press: 19 December 2013, pp. 405-408
Print publication: November 2013
The Galactic Halo Ionising Field
J. Bland-Hawthorn, P. R. Maloney
Journal: Publications of the Astronomical Society of Australia / Volume 14 / Issue 1 / 1997
Published online by Cambridge University Press: 05 March 2013, pp. 59-63
There has been much debate in recent decades as to what fraction of ionising photons from star-forming regions in the Galactic disk escape into the halo. The recent detection of the Magellanic Stream in optical line emission at the CTIO 4 m and the AAT 3·9 m telescopes may now provide the strongest evidence that at least some of the radiation escapes the disk completely. We present a simple model to demonstrate that, while the distance to the Magellanic Stream is uncertain, the observed emission measures (ε m ≈ 0·5 – 1 cm−6 pc) are most plausibly explained by photoionisation due to hot, young stars. This model requires that the mean Lyman-limit opacity perpendicular to the disk is τ LL ≈ 3, and the covering fraction of the resolved clouds is close to unity. Alternative sources (e.g. shock, halo, LMC or metagalactic radiation) contribute negligible ionising flux.
The Science Case for PILOT III: the Nearby Universe
J. S. Lawrence, M. C. B. Ashley, J. Bailey, D. Barrado y Navascues, T. R. Bedding, J. Bland-Hawthorn, I. Bond, H. Bruntt, M. G. Burton, M.-R. Cioni, C. Eiroa, N. Epchtein, L. Kiss, P. O. Lagage, V. Minier, A. Mora, K. Olsen, P. Persi, W. Saunders, D. Stello, J. W. V. Storey, C. Tinney, P. Yock
Published online by Cambridge University Press: 05 March 2013, pp. 415-438
PILOT (the Pathfinder for an International Large Optical Telescope) is a proposed 2.5-m optical/infrared telescope to be located at Dome C on the Antarctic plateau. The atmospheric conditions at Dome C deliver a high sensitivity, high photometric precision, wide-field, high spatial resolution, and high-cadence imaging capability to the PILOT telescope. These capabilities enable a unique scientific potential for PILOT, which is addressed in this series of papers. The current paper presents a series of projects dealing with the nearby Universe that have been identified as key science drivers for the PILOT facility. Several projects are proposed that examine stellar populations in nearby galaxies and stellar clusters in order to gain insight into the formation and evolution processes of galaxies and stars. A series of projects will investigate the molecular phase of the Galaxy and explore the ecology of star formation, and investigate the formation processes of stellar and planetary systems. Three projects in the field of exoplanet science are proposed: a search for free-floating low-mass planets and dwarfs, a program of follow-up observations of gravitational microlensing events, and a study of infrared light-curves for previously discovered exoplanets. Three projects are also proposed in the field of planetary and space science: optical and near-infrared studies aimed at characterising planetary atmospheres, a study of coronal mass ejections from the Sun, and a monitoring program searching for small-scale Low Earth Orbit satellite debris items.
The Science Case for PILOT I: Summary and Overview
J. S. Lawrence, M. C. B. Ashley, J. Bailey, D. Barrado y Navascues, T. R. Bedding, J. Bland-Hawthorn, I. Bond, F. Boulanger, R. Bouwens, H. Bruntt, A. Bunker, D. Burgarella, M. G. Burton, M. Busso, D. Coward, M.-R. Cioni, G. Durand, C. Eiroa, N. Epchtein, N. Gehrels, P. Gillingham, K. Glazebrook, R. Haynes, L. Kiss, P. O. Lagage, T. Le Bertre, C. Mackay, J. P. Maillard, A. McGrath, V. Minier, A. Mora, K. Olsen, P. Persi, K. Pimbblet, R. Quimby, W. Saunders, B. Schmidt, D. Stello, J. W. V. Storey, C. Tinney, P. Tremblin, J. C. Wheeler, P. Yock
PILOT (the Pathfinder for an International Large Optical Telescope) is a proposed 2.5-m optical/infrared telescope to be located at Dome C on the Antarctic plateau. Conditions at Dome C are known to be exceptional for astronomy. The seeing (above ∼30 m height), coherence time, and isoplanatic angle are all twice as good as at typical mid-latitude sites, while the water-vapour column, and the atmosphere and telescope thermal emission are all an order of magnitude better. These conditions enable a unique scientific capability for PILOT, which is addressed in this series of papers. The current paper presents an overview of the optical and instrumentation suite for PILOT and its expected performance, a summary of the key science goals and observational approach for the facility, a discussion of the synergies between the science goals for PILOT and other telescopes, and a discussion of the future of Antarctic astronomy. Paper II and Paper III present details of the science projects divided, respectively, between the distant Universe (i.e. studies of first light, and the assembly and evolution of structure) and the nearby Universe (i.e. studies of Local Group galaxies, the Milky Way, and the Solar System).
Science Programs for a 2-m Class Telescope at Dome C, Antarctica: PILOT, the Pathfinder for an International Large Optical Telescope
M. G. Burton, J. S. Lawrence, M. C. B. Ashley, J. A. Bailey, C. Blake, T. R. Bedding, J. Bland-Hawthorn, I. A. Bond, K. Glazebrook, M. G. Hidas, G. Lewis, S. N. Longmore, S. T. Maddison, S. Mattila, V. Minier, S. D. Ryder, R. Sharp, C. H. Smith, J. W. V. Storey, C. G. Tinney, P. Tuthill, A. J. Walsh, W. Walsh, M. Whiting, T. Wong, D. Woods, P. C. M. Yock
The cold, dry, and stable air above the summits of the Antarctic plateau provides the best ground-based observing conditions from optical to sub-millimetre wavelengths to be found on the Earth. Pathfinder for an International Large Optical Telescope (PILOT) is a proposed 2 m telescope, to be built at Dome C in Antarctica, able to exploit these conditions for conducting astronomy at optical and infrared wavelengths. While PILOT is intended as a pathfinder towards the construction of future grand-design facilities, it will also be able to undertake a range of fundamental science investigations in its own right. This paper provides the performance specifications for PILOT, including its instrumentation. It then describes the kinds of projects that it could best conduct. These range from planetary science to the search for other solar systems, from star formation within the Galaxy to the star formation history of the Universe, and from gravitational lensing caused by exo-planets to that produced by the cosmic web of dark matter. PILOT would be particularly powerful for wide-field imaging at infrared wavelengths, achieving near diffraction-limited performance with simple tip–tilt wavefront correction. PILOT would also be capable of near diffraction-limited performance in the optical wavebands, as well be able to open new wavebands for regular ground-based observation, in the mid-IR from 17 to 40 μm and in the sub-millimetre at 200 μm.
GASKAP—The Galactic ASKAP Survey
John M. Dickey, Naomi McClure-Griffiths, Steven J. Gibson, José F. Gómez, Hiroshi Imai, Paul Jones, Snežana Stanimirović, Jacco Th. Van Loon, Andrew Walsh, A. Alberdi, G. Anglada, L. Uscanga, H. Arce, M. Bailey, A. Begum, B. Wakker, N. Ben Bekhti, P. Kalberla, B. Winkel, K. Bekki, B.-Q. For, L. Staveley-Smith, T. Westmeier, M. Burton, M. Cunningham, J. Dawson, S. Ellingsen, P. Diamond, J. A. Green, A. S. Hill, B. Koribalski, D. McConnell, J. Rathborne, M. Voronkov, K. A. Douglas, J. English, H. Alyson Ford, F. J. Lockman, T. Foster, Y. Gomez, A. Green, J. Bland-Hawthorn, S. Gulyaev, M. Hoare, G. Joncas, J.-H. Kang, C. R. Kerton, B.-C. Koo, D. Leahy, N. Lo, V. Migenes, J. Nakashima, Y. Zhang, D. Nidever, J. E. G. Peek, D. Tafoya, W. Tian, D. Wu
Published online by Cambridge University Press: 24 January 2013, e003
A survey of the Milky Way disk and the Magellanic System at the wavelengths of the 21-cm atomic hydrogen (H i) line and three 18-cm lines of the OH molecule will be carried out with the Australian Square Kilometre Array Pathfinder telescope. The survey will study the distribution of H i emission and absorption with unprecedented angular and velocity resolution, as well as molecular line thermal emission, absorption, and maser lines. The area to be covered includes the Galactic plane (|b| < 10°) at all declinations south of δ = +40°, spanning longitudes 167° through 360°to 79° at b = 0°, plus the entire area of the Magellanic Stream and Clouds, a total of 13 020 deg2. The brightness temperature sensitivity will be very good, typically σT≃ 1 K at resolution 30 arcsec and 1 km s−1. The survey has a wide spectrum of scientific goals, from studies of galaxy evolution to star formation, with particular contributions to understanding stellar wind kinematics, the thermal phases of the interstellar medium, the interaction between gas in the disk and halo, and the dynamical and thermal states of gas at various positions along the Magellanic Stream.
Elisheva Carlebach. Palaces of Time: Jewish Calendar and Culture in Early Modern Europe. Cambridge, MA: Belknap Press of Harvard University Press, 2011. xi, 292 pp. 53 illustrations.
Journal: AJS Review / Volume 36 / Issue 1 / April 2012
Print publication: April 2012
Experimental studies of supersonic radiatively cooled plasma jets
S.V. Lebedev, F. Suzuki-Vidal, M. Bocchi, G.F. Swadling, G. Burdiak, S.N. Bland, P. de Grouchy, A.J. Harvey-Thompson, E. Khoory, S. Patankar, L. Pickworth, J. Skidmore, R. Smith, J.P. Chittenden, M. Krishnan, R. Madden, K. Wilson-Elliot, A. Ciardi, A. Frank
Journal: European Astronomical Society Publications Series / Volume 58 / 2012
Published online by Cambridge University Press: 13 February 2013, pp. 133-136
Properties of radiatively cooled supersonic plasma jets formed by ablation of thin Al foils driven by 1.4 MA, 250 ns current pulse are presented. The jets are highly collimated with half-opening angles of ~2°. Measurements of the flow velocity (~60 km/s) and plasma temperature (~15 eV) in the jet with Thomson scattering diagnostic give internal Mach number of M ~ 3, suggesting additional collimation of the jet by toroidal magnetic fields.
Jet-ambient interaction of a supersonic, radiatively-cooled jet in laboratory experiments
F. Suzuki-Vidal, M. Bocchi, S.V. Lebedev, J. Skidmore, G. Swadling, G. Burdiak, A.J. Harvey-Thompson, P. de Grouchy, S.N. Bland, G.N. Hall, E. Khoory, L. Pickworth, L. Suttle, J.P. Chittenden, M. Krishnan, K. Wilson-Elliot, R. Madden, A. Ciardi, A. Frank
The formation of supersonic, radiatively cooled plasma jets with applications to laboratory astrophysics has been an active area of research on the MAGPIE generator. One of the ways of producing astrophysically-relevant jets in the laboratory is by using the ablation of plasma from a radial foil Z-pinch. In this configuration a ~1.4 MA, 250 ns current pulse is introduced into an aluminium disk with a thickness of 15 μm. The ablated plasma from the foil converges on the axis, producing a steady and collimated jet with a typical axial velocity of ~100 km/s. The setup allows for the addition of argon above the foil for jet-ambient interaction studies. The interaction is characterised by the formation of several shock features, which are presented and discussed from experimental data and numerical simulations.