Publications of the Astronomical Society of Australia (14)
European Journal of Anaesthesiology (3)
Proceedings of the International Astronomical Union (1)
The Evolutionary Map of the Universe Pilot Survey – ADDENDUM
Ray P. Norris, Joshua Marvil, J. D. Collier, Anna D. Kapińska, Andrew N. O'Brien, L. Rudnick, Heinz Andernach, Jacobo Asorey, Michael J. I. Brown, Marcus Brüggen, Evan Crawford, Jayanne English, Syed Faisal ur Rahman, Miroslav D. Filipović, Yjan Gordon, Gülay Gürkan, Catherine Hale, Andrew M. Hopkins, Minh T. Huynh, Kim HyeongHan, M. James Jee, Bärbel S. Koribalski, Emil Lenc, Kieran Luken, David Parkinson, Isabella Prandoni, Wasim Raja, Thomas H. Reiprich, Christopher J. Riseley, Stanislav S. Shabala, Jaimie R. Sheil, Tessa Vernstrom, Matthew T. Whiting, James R. Allison, C. S. Anderson, Lewis Ball, Martin Bell, John Bunton, T. J. Galvin, Neeraj Gupta, Aidan Hotan, Colin Jacka, Peter J. Macgregor, Elizabeth K. Mahony, Umberto Maio, Vanessa Moss, M. Pandey-Pommier, Maxim A. Voronkov
The Evolutionary Map of the Universe pilot survey
Australian SKA Pathfinder
Published online by Cambridge University Press: 07 September 2021, e046
We present the data and initial results from the first pilot survey of the Evolutionary Map of the Universe (EMU), observed at 944 MHz with the Australian Square Kilometre Array Pathfinder (ASKAP) telescope. The survey covers $270 \,\mathrm{deg}^2$ of an area covered by the Dark Energy Survey, reaching a depth of 25–30 $\mu\mathrm{Jy\ beam}^{-1}$ rms at a spatial resolution of $\sim$ 11–18 arcsec, resulting in a catalogue of $\sim$ 220 000 sources, of which $\sim$ 180 000 are single-component sources. Here we present the catalogue of single-component sources, together with (where available) optical and infrared cross-identifications, classifications, and redshifts. This survey explores a new region of parameter space compared to previous surveys. Specifically, the EMU Pilot Survey has a high density of sources, and also a high sensitivity to low surface brightness emission. These properties result in the detection of types of sources that were rarely seen in or absent from previous surveys. We present some of these new results here.
Unexpected circular radio objects at high Galactic latitude
Ray P. Norris, Huib T. Intema, Anna D. Kapińska, Bärbel S. Koribalski, Emil Lenc, L. Rudnick, Rami Z. E. Alsaberi, Craig Anderson, G. E. Anderson, E. Crawford, Roland Crocker, Jayanne English, Miroslav D. Filipović, Tim J. Galvin, Andrew M. Hopkins, Natasha Hurley-Walker, Susumu Inoue, Kieran Luken, Peter J. Macgregor, Pero Manojlović, Josh Marvil, Andrew N. O'Brien, Laurence Park, Wasim Raja, Devika Shobhana, Tiziana Venturi, Jordan D. Collier, Catherine Hale, Aidan Hotan, Vanessa Moss, Matthew Whiting
Published online by Cambridge University Press: 18 January 2021, e003
We have found a class of circular radio objects in the Evolutionary Map of the Universe Pilot Survey, using the Australian Square Kilometre Array Pathfinder telescope. The objects appear in radio images as circular edge-brightened discs, about one arcmin diameter, that are unlike other objects previously reported in the literature. We explore several possible mechanisms that might cause these objects, but none seems to be a compelling explanation.
P-1339 - Agoraphobia Hemiparesis and Hemihypesthesia in a Transsexual Patient - Case Report
D. Markovic-Zigic, A. Starcevic, B. Filipovic, M. Dakovic, V. Andrejic
Transsexualism is a gender identity disorder soon to be removed from the DSM criteria for mental disorders. The actual developmental/congenital origin of the disorder has yet to be established. One of the theories involves morphological and neuro-hormonal modification in the corpus callosum as a possible substrate.
Diagnostic assessment of a 22 year old female - male transsexual patient with a history of agoraphobia and migraine, reporting intermittent symptoms of numbness of left side of body and cheek and headaches.
Data on personal/family history was obtained and neurological examination was performed. MRI scan was acquired with a 1.5 T Siemens Magnetom system with a standard head coil. Sagittal three-dimensional 3D RAGE, contiguous 1.0 mm slices, 1 acquisition sequences were obtained.
Results and discussion: Family history of anxiety disorder was confirmed. Symptoms appeared following reduction of anxiolytic medication and emotional crisis. Neurological status showed signs of left pyramid deficit. NMR scan findings showed bilateral arachnoid cysts in genu corpus callosum probably of congenital origin. Co-morbidity versus concomitant disorders of psychiatric, neurological and congenital origin were discussed.
PKS 2250–351: A giant radio galaxy in Abell 3936
GAMA Legacy ATCA Southern Survey
N. Seymour, M. Huynh, S. S. Shabala, J. Rogers, L. J. M. Davies, R. J. Turner, A. O'Brien, C. H. Ishwara-Chandra, J. E. Thorne, T. J. Galvin, T. Jarrett, H. Andernach, C. Anderson, J. Bunton, K. Chow, J. D. Collier, S. Driver, M. D. Filipovic, G. Gürkan, A. M. Hopkins, A. D. Kapińska, D. A. Leahy, J. Marvil, P. Manojlovic, R. P. Norris, C. Phillips, A. Robotham, L. Rudnick, V. Singh, S. V. White
Published online by Cambridge University Press: 25 March 2020, e013
We present a detailed analysis of the radio galaxy PKS $2250{-}351$ , a giant of 1.2 Mpc projected size, its host galaxy, and its environment. We use radio data from the Murchison Widefield Array, the upgraded Giant Metre-wavelength Radio Telescope, the Australian Square Kilometre Array Pathfinder, and the Australia Telescope Compact Array to model the jet power and age. Optical and IR data come from the Galaxy And Mass Assembly (GAMA) survey and provide information on the host galaxy and environment. GAMA spectroscopy confirms that PKS $2250{-}351$ lies at $z=0.2115$ in the irregular, and likely unrelaxed, cluster Abell 3936. We find its host is a massive, 'red and dead' elliptical galaxy with negligible star formation but with a highly obscured active galactic nucleus dominating the mid-IR emission. Assuming it lies on the local M– $\sigma$ relation, it has an Eddington accretion rate of $\lambda_{\rm EDD}\sim 0.014$ . We find that the lobe-derived jet power (a time-averaged measure) is an order of magnitude greater than the hotspot-derived jet power (an instantaneous measure). We propose that over the lifetime of the observed radio emission ( ${\sim} 300\,$ Myr), the accretion has switched from an inefficient advection-dominated mode to a thin disc efficient mode, consistent with the decrease in jet power. We also suggest that the asymmetric radio morphology is due to its environment, with the host of PKS $2250{-}351$ lying to the west of the densest concentration of galaxies in Abell 3936.
Science with the Murchison Widefield Array: Phase I results and Phase II opportunities – Corrigendum
A. P. Beardsley, M. Johnston-Hollitt, C. M. Trott, J. C. Pober, J. Morgan, D. Oberoi, D. L. Kaplan, C. R. Lynch, G. E. Anderson, P. I. McCauley, S. Croft, C. W. James, O. I. Wong, C. D. Tremblay, R. P. Norris, I. H. Cairns, C. J. Lonsdale, P. J. Hancock, B. M. Gaensler, N. D. R. Bhat, W. Li, N. Hurley-Walker, J. R. Callingham, N. Seymour, S. Yoshiura, R. C. Joseph, K. Takahashi, M. Sokolowski, J. C. A. Miller-Jones, J. V. Chauhan, I. Bojičić, M. D. Filipović, D. Leahy, H. Su, W. W. Tian, S. J. McSweeney, B. W. Meyers, S. Kitaeff, T. Vernstrom, G. Gürkan, G. Heald, M. Xue, C. J. Riseley, S. W. Duchesne, J. D. Bowman, D. C. Jacobs, B. Crosse, D. Emrich, T. M. O. Franzen, L. Horsley, D. Kenney, M. F. Morales, D. Pallot, K. Steele, S. J. Tingay, M. Walker, R. B. Wayth, A. Williams, C. Wu
Science with the Murchison Widefield Array: Phase I results and Phase II opportunities
Published online by Cambridge University Press: 13 December 2019, e050
The Murchison Widefield Array (MWA) is an open access telescope dedicated to studying the low-frequency (80–300 MHz) southern sky. Since beginning operations in mid-2013, the MWA has opened a new observational window in the southern hemisphere enabling many science areas. The driving science objectives of the original design were to observe 21 cm radiation from the Epoch of Reionisation (EoR), explore the radio time domain, perform Galactic and extragalactic surveys, and monitor solar, heliospheric, and ionospheric phenomena. All together $60+$ programs recorded 20 000 h producing 146 papers to date. In 2016, the telescope underwent a major upgrade resulting in alternating compact and extended configurations. Other upgrades, including digital back-ends and a rapid-response triggering system, have been developed since the original array was commissioned. In this paper, we review the major results from the prior operation of the MWA and then discuss the new science paths enabled by the improved capabilities. We group these science opportunities by the four original science themes but also include ideas for directions outside these categories.
New candidate radio supernova remnants detected in the GLEAM survey over 345° < l < 60°, 180° < l < 240°
N. Hurley-Walker, M. D. Filipović, B. M. Gaensler, D. A. Leahy, P. J. Hancock, T. M. O. Franzen, A. R. Offringa, J. R. Callingham, L. Hindson, C. Wu, M. E. Bell, B.-Q. For, M. Johnston-Hollitt, A. D. Kapińska, J. Morgan, T. Murphy, B. McKinley, P. Procopio, L. Staveley-Smith, R. B. Wayth, Q. Zheng
We have detected 27 new supernova remnants (SNRs) using a new data release of the GLEAM survey from the Murchison Widefield Array telescope, including the lowest surface brightness SNR ever detected, G 0.1 – 9.7. Our method uses spectral fitting to the radio continuum to derive spectral indices for 26/27 candidates, and our low-frequency observations probe a steeper spectrum population than previously discovered. None of the candidates have coincident WISE mid-IR emission, further showing that the emission is non-thermal. Using pulsar associations we derive physical properties for six candidate SNRs, finding G 0.1 – 9.7 may be younger than 10 kyr. Sixty per cent of the candidates subtend areas larger than 0.2 deg2 on the sky, compared to < 25% of previously detected SNRs. We also make the first detection of two SNRs in the Galactic longitude range 220°–240°.
Candidate radio supernova remnants observed by the GLEAM survey over 345° < l < 60° and 180° < l < 240°
N. Hurley-Walker, B. M. Gaensler, D. A. Leahy, M. D. Filipović, P. J. Hancock, T. M. O. Franzen, A. R. Offringa, J. R. Callingham, L. Hindson, C. Wu, M. E. Bell, B.-Q. For, M. Johnston-Hollitt, A. D. Kapińska, J. Morgan, T. Murphy, B. McKinley, P. Procopio, L. Staveley-Smith, R. B. Wayth, Q. Zheng
We examined the latest data release from the GaLactic and Extragalactic All-sky Murchison Widefield Array (GLEAM) survey covering 345° < l < 60° and 180° < l < 240°, using these data and that of the Widefield Infrared Survey Explorer to follow up proposed candidate Supernova Remnant (SNR) from other sources. Of the 101 candidates proposed in the region, we are able to definitively confirm ten as SNRs, tentatively confirm two as SNRs, and reclassify five as H ii regions. A further two are detectable in our images but difficult to classify; the remaining 82 are undetectable in these data. We also investigated the 18 unclassified Multi-Array Galactic Plane Imaging Survey (MAGPIS) candidate SNRs, newly confirming three as SNRs, reclassifying two as H ii regions, and exploring the unusual spectra and morphology of two others.
Discovering exotic AGN behind the Magellanic Clouds
Clara M. Pennock, Jacco Th. van Loon, Cameron P. M. Bell, Miroslav D. Filipović, Tana D. Joseph, Eleni Vardoulaki
Journal: Proceedings of the International Astronomical Union / Volume 15 / Issue S356 / October 2019
Published online by Cambridge University Press: 29 January 2021, pp. 335-338
Print publication: October 2019
The nearby Magellanic Clouds system covers more than 200 square degrees on the sky. Much of it has been mapped across the electromagnetic spectrum at high angular resolution and sensitivity –X-ray (XMM-Newton), UV (UVIT), optical (SMASH), IR (VISTA, WISE, Spitzer, Herschel), radio (ATCA, ASKAP, MeerKAT). This provides us with an excellent dataset to explore the galaxy populations behind the stellar-rich Magellanic Clouds. We seek to identify and characterise AGN via machine learning algorithms on this exquisite data set. Our project focuses not on establishing sequences and distributions of common types of galaxies and active galactic nuclei (AGN), but seeks to identify extreme examples, building on the recent accidental discoveries of unique AGN behind the Magellanic Clouds.
The Phase II Murchison Widefield Array: Design overview
Randall B. Wayth, Steven J. Tingay, Cathryn M. Trott, David Emrich, Melanie Johnston-Hollitt, Ben McKinley, B. M. Gaensler, A. P. Beardsley, T. Booler, B. Crosse, T. M. O. Franzen, L. Horsley, D. L. Kaplan, D. Kenney, M. F. Morales, D. Pallot, G. Sleap, K. Steele, M. Walker, A. Williams, C. Wu, Iver. H. Cairns, M. D. Filipovic, S. Johnston, T. Murphy, P. Quinn, L. Staveley-Smith, R. Webster, J. S. B. Wyithe
We describe the motivation and design details of the 'Phase II' upgrade of the Murchison Widefield Array radio telescope. The expansion doubles to 256 the number of antenna tiles deployed in the array. The new antenna tiles enhance the capabilities of the Murchison Widefield Array in several key science areas. Seventy-two of the new tiles are deployed in a regular configuration near the existing array core. These new tiles enhance the surface brightness sensitivity of the array and will improve the ability of the Murchison Widefield Array to estimate the slope of the Epoch of Reionisation power spectrum by a factor of ∼3.5. The remaining 56 tiles are deployed on long baselines, doubling the maximum baseline of the array and improving the array u, v coverage. The improved imaging capabilities will provide an order of magnitude improvement in the noise floor of Murchison Widefield Array continuum images. The upgrade retains all of the features that have underpinned the Murchison Widefield Array's success (large field of view, snapshot image quality, and pointing agility) and boosts the scientific potential with enhanced imaging capabilities and by enabling new calibration strategies.
The Mopra Southern Galactic Plane CO Survey—Data Release 3
Catherine Braiding, G. F. Wong, N. I. Maxted, D. Romano, M. G. Burton, R. Blackwell, M. D. Filipović, M. S. R. Freeman, B. Indermuehle, J. Lau, D. Rebolledo, G. Rowell, C. Snoswell, N. F. H. Tothill, F. Voisin, P. de Wilt
Published online by Cambridge University Press: 17 August 2018, e029
We present observations of 50 deg2 of the Mopra carbon monoxide (CO) survey of the Southern Galactic Plane, covering Galactic longitudes l = 300–350° and latitudes |b| ⩽ 0.5°. These data have been taken at 0.6 arcmin spatial resolution and 0.1 km s−1spectral resolution, providing an unprecedented view of the molecular clouds and gas of the Southern Galactic Plane in the 109–115 GHz J = 1–0 transitions of 12CO, 13CO, C18O, and C17O.
We present a series of velocity-integrated maps, spectra, and position-velocity plots that illustrate Galactic arm structures and trace masses on the order of ~106 M⊙ deg−2, and include a preliminary catalogue of C18O clumps located between l = 330–340°. Together with the information about the noise statistics of the survey, these data can be retrieved from the Mopra CO website and the PASA data store.
A Multi-Frequency Study of the Milky Way-Like Spiral Galaxy NGC 6744
Miranda Yew, Miroslav D. Filipović, Quentin Roper, Jordan D. Collier, Evan J. Crawford, Thomas H. Jarrett, Nicholas F. H. Tothill, Andrew N. O'Brien, Marko Z. Pavlović, Thomas G. Pannuti, Timothy J. Galvin, Anna D. Kapińska, Michelle E. Cluver, Julie K. Banfield, Eric M. Schlegel, Nigel Maxted, Kevin R. Grieve
We present a multi-frequency study of the intermediate spiral SAB(r)bc type galaxy NGC 6744, using available data from the Chandra X-Ray telescope, radio continuum data from the Australia Telescope Compact Array and Murchison Widefield Array, and Wide-field Infrared Survey Explorer infrared observations. We identify 117 X-ray sources and 280 radio sources. Of these, we find nine sources in common between the X-ray and radio catalogues, one of which is a faint central black hole with a bolometric radio luminosity similar to the Milky Way's central black hole. We classify 5 objects as supernova remnant (SNR) candidates, 2 objects as likely SNRs, 17 as H ii regions, 1 source as an AGN; the remaining 255 radio sources are categorised as background objects and one X-ray source is classified as a foreground star. We find the star-formation rate (SFR) of NGC 6744 to be in the range 2.8–4.7 M⊙~yr − 1 signifying the galaxy is still actively forming stars. The specific SFR of NGC 6744 is greater than that of late-type spirals such as the Milky Way, but considerably less that that of a typical starburst galaxy.
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
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, H0) 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.
A Digital Video System for Observing and Recording Occultations
M. A. (Tony) Barry, Dave Gault, Hristo Pavlov, William Hanna, Alistair McEwan, Miroslav D. Filipović
Stellar occultations by asteroids and outer solar system bodies can offer ground based observers with modest telescopes and camera equipment the opportunity to probe the shape, size, atmosphere, and attendant moons or rings of these distant objects. The essential requirements of the camera and recording equipment are: good quantum efficiency and low noise; minimal dead time between images; good horological faithfulness of the image timestamps; robustness of the recording to unexpected failure; and low cost. We describe an occultation observing and recording system which attempts to fulfil these requirements and compare the system with other reported camera and recorder systems. Five systems have been built, deployed, and tested over the past three years, and we report on three representative occultation observations: one being a 9 ± 1.5 s occultation of the trans-Neptunian object 28978 Ixion (mv =15.2) at 3 seconds per frame; one being a 1.51 ± 0.017 s occultation of Deimos, the 12 km diameter satellite of Mars, at 30 frames per second; and one being a 11.04 ± 0.4 s occultation, recorded at 7.5 frames per second, of the main belt asteroid 361 Havnia, representing a low magnitude drop (Δmv = ~0.4) occultation.
Verifying Timestamps of Occultation Observation Systems
M. A.(Tony) Barry, Dave Gault, Greg Bolt, Alistair McEwan, Miroslav D. Filipović, Graeme L. White
Published online by Cambridge University Press: 22 April 2015, e014
We describe an image timestamp verification system to determine the exposure timing characteristics and continuity of images made by an imaging camera and recorder, with reference to Coordinated Universal Time. The original use was to verify the timestamps of stellar occultation recording systems, but the system is applicable to lunar flashes, planetary transits, sprite recording, or any area where reliable timestamps are required. The system offers good temporal resolution (down to 2 ms, referred to Coordinated Universal Time) and provides exposure duration and interframe dead time information. The system uses inexpensive, off-the-shelf components, requires minimal assembly, and requires no high-voltage components or connections. We also describe an application to load fits (and other format) image files, which can decode the verification image timestamp. Source code, wiring diagrams, and built applications are provided to aid the construction and use of the device.
Intra-operative myocardial ischaemia cannot be detected by analysis of transmitral inflow patterns in patients undergoing off-pump coronary surgery
J. Wang, M. D. Seeberger, K. Skarvan, I. Michaux, F. Bernet, R. Arsenic, P. Buser, M. Filipovic
Journal: European Journal of Anaesthesiology / Volume 25 / Issue 1 / January 2008
Background and objective
Transmitral inflow patterns have been used for detection of myocardial ischaemia. However, its diagnostic value has not been tested in anaesthetized and mechanically ventilated patients undergoing coronary artery bypass graft surgery.
Transmitral inflow patterns were studied by transoesophageal Doppler echocardiography in 43 patients undergoing coronary artery bypass graft surgery without cardiopulmonary bypass after opening of the sternum (baseline) and during grafting of the left anterior descending artery. Peak early (E) and peak late (A) transmitral velocities and their ratio (E/A) were recorded. Myocardial ischaemia was defined by standard criteria using two-dimensional echocardiography and seven-lead electrocardiogram.
Thirty-one patients (64 ± 8 yr, 9 women) fulfilled the predefined inclusion criteria for analysis. During distal revascularization, 16 patients showed myocardial ischaemia and 15 did not. The use of vasoactive drugs, haemodynamic findings and transmitral inflow patterns were similar in both groups at baseline and during grafting. In the ischaemic group, E was 67.1 ± 13.9 cm s−1 at baseline and 69.5 ± 23.2 cm s−1 during grafting, and the E/A ratios were 1.3 ± 0.3 and 1.4 ± 0.9, respectively. In the non-ischaemic group, E was 64.0 ± 17.1 cm s−1 at baseline and 60.9 ± 14.8 cm s−1 during grafting, and the E/A ratios were 1.4 ± 0.7 and 1.2 ± 0.3, respectively.
Analysis of Doppler findings of transmitral inflow patterns did not allow for detection of myocardial ischaemia during surgical revascularization of the myocardium.
Supernova Remnants in the Magellanic Clouds
M. D. Filipović, L. Staveley-Smith, W. Reid, P. A. Jones
Journal: Symposium - International Astronomical Union / Volume 218 / 2004
Published online by Cambridge University Press: 19 July 2016, pp. 87-88
Print publication: 2004
A study of the nature and the spatial distribution of over 250 discrete radio sources (HII regions and SNRs) in the Magellanic Clouds (MCs) is underway. A multi-frequency comparison of these sources involves the latest radio, IR, optical and X-ray surveys with angular resolution of <1′. Special emphasis is given to the MC SNRs. Their morphology, birth rate and overall properties are investigated and compared with Galactic SNRs and SNRs from other nearby galaxies. Also, we are investigating the radio source distribution throughout both MCs.
The Distance and Distribution of Galactic Supernova Remnants from the PMN Survey Sample
M. Stupar, M. D. Filipović, T. G. Pannuti, Q. A. Parker
We have used the Parkes-MIT-NRAO (PMN) radio survey, at a common frequency of 4.85 GHz (λ=6 cm), to study the distribution of Galactic shell supernova remnants (SNRs). We estimate distances and distribution of the Galactic shell SNRs and find the peak of distances to be between 4 and 6 kpc. Our two-dimensional model of the distribution of Galactic shell SNRs shows a concentration between the Sagittarius and the Scutum arms.
Doppler indices of diastolic transmitral flow velocity are invalid indicators of myocardial ischaemia during high-dose dobutamine infusion in anaesthetized patients
M. Filipovic, M. D. Seeberger, R. Rohlfs, O. Dergeloo, W. Studer, D. Atar, P. Buser, K. Skarvan
Journal: European Journal of Anaesthesiology / Volume 19 / Issue 11 / November 2002
Background and objective: Doppler echocardiography of diastolic transmitral flow velocity is more sensitive for the detection of myocardial ischaemia in awake patients than echocardiographic analysis of systolic wall motion. However, its diagnostic value in anaesthetized patients is unknown.
Methods: Doppler indices of diastolic transmitral flow velocity previously found to be highly sensitive for detecting ischaemia in awake patients were studied in 72 anaesthetized patients with documented coronary artery disease undergoing dobutamine stress echocardiography. These Doppler indices were compared with standard echocardiographic and electrocardiographic criteria for ischaemia.
Results: Sixty-five patients showed evidence of ischaemia by standard echocardiographic and/or electrocardiographic criteria, and seven patients did not. Regardless of evidence of ischaemia by standard criteria, the Doppler indices changed similarly in both groups. Accordingly, only a minority of anaesthetized patients displayed the changes in Doppler indices of diastolic transmitral flow previously suggested to be sensitive for detecting ischaemia.
Conclusions: The results do not confirm the diagnostic value of Doppler echocardiography of diastolic transmitral flow velocity for detecting ischaemia in anaesthetized patients undergoing dobutamine stress echocardiography during positive-pressure ventilation of the lungs.