45 results on '"Sharp, Rob"'
Search Results
2. Observational window effects on multi-object reverberation mapping.
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Malik, Umang, Sharp, Rob, Martini, Paul, Davis, Tamara M, Tucker, Brad E, Yu, Zhefu, Penton, Andrew, Lewis, Geraint F, and Calcino, Josh
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ACTIVE galactic nuclei , *TIME dilation , *CAMPAIGN management , *DARK energy , *ACTIVE galaxies , *SEYFERT galaxies - Abstract
Contemporary reverberation mapping campaigns are employing wide-area photometric data and high-multiplex spectroscopy to efficiently monitor hundreds of active galactic nuclei (AGNs). However, the interaction of the window function(s) imposed by the observation cadence with the reverberation lag and AGN variability time-scales (intrinsic to each source over a range of luminosities) impact our ability to recover these fundamental physical properties. Time dilation effects due to the sample source redshift distribution introduce added complexity. We present comprehensive analysis of the implications of observational cadence, seasonal gaps, and campaign baseline duration (i.e. the survey window function) for reverberation lag recovery. We find that the presence of a significant seasonal gap dominates the efficacy of any given campaign strategy for lag recovery across the parameter space, particularly for those sources with observed-frame lags above 100 d. Using the Australian Dark Energy Survey as a baseline, we consider the implications of this analysis for the 4MOST/Time-Domain Extragalactic Survey campaign providing concurrent follow-up of the Legacy Survey of Space and Time deep-drilling fields, as well as upcoming programmes. We conclude that the success of such surveys will be critically limited by the seasonal visibility of some potential field choices, but show significant improvement from extending the baseline. Optimizing the sample selection to fit the window function will improve survey efficacy. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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3. Professional and Personal Identity, Precarity and Discrimination in Global Arts Journalism.
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Sharp, Rob and Vodanovic, Lucia
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SELF , *JOURNALISM , *PRECARITY , *CAPITAL movements , *PROFESSIONAL identity , *COVID-19 pandemic - Abstract
Arts journalism, journalism on the arts and entertainment industries, has been primarily defined in a Western European context within Journalism Studies. Yet this neglects the globalised nature of arts and entertainment production and consumption and the mobile reporters who cover it, and the nationally contingent challenges and opportunities they face. In a world still grappling with the Covid-19 pandemic, arts reporters face a triple threat: the precarity of what is often a freelance career, the financial disruption of the global media and entertainment industries, and the biases of a media ecosystem that favours reporters from the Global North. Drawing on 24 interviews with arts journalists from 12 different countries in four continents in 2020–2021, we explore how such journalists are increasingly subsidising their work with employment beyond the media sector. Arts journalists from Europe grapple with complex issues relating to their professional and personal identities, in contrast to journalists from the Global South, where questions relate primarily to economic and structural challenges. Journalists from West Africa interviewed face increasing if sporadic interest from media organisations in global economic centres, and the emerging content possibilities of internationally funded digital and streaming platforms, mirroring broader economic flows of capital and labour. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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4. HIGH PREGNANCY RATES IN TWO-YEAR-OLD WILD HORSES.
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Grant, Lisa, Sharp, Rob, Griffin, Paul, Weikel, Julie, and Pielstick, Leon
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WILD horses , *HORSE breeding , *DIGITAL rectal examination , *PREGNANCY , *MARES - Abstract
In November 2018, we screened 315 feral Horse mares via veterinary rectal palpation and trans-rectal ultrasound, approximately 1 mo after their capture and removal from the Warm Springs herd management area in Oregon. We documented a pregnancy rate (58.3%) in 2-y-old mares that was nearly 3 times higher than previously published results. For 1-y-old mares (10.8% pregnant), and for mares pooled over all ages (64.4% pregnant), pregnancy rates were within the range of pregnancy rates reported from other feral Horse populations. High pregnancy rates in 2-y-old mares could contribute to higher than expected herd growth rates in feral Horses. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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5. The Australia Telescope Large Area Survey: spectroscopic catalogue and radio luminosity functions.
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Mao, Minnie Y., Sharp, Rob, Norris, Ray P., Hopkins, Andrew M., Seymour, Nick, Lovell, James E. J., Middelberg, Enno, Randall, Kate E., Sadler, Elaine M., Saikia, D. J., Shabala, Stanislav S., and Zinn, Peter-Christian
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STELLAR luminosity function , *TELESCOPES , *OPTICAL spectroscopy , *STAR formation - Abstract
ABSTRACT The Australia Telescope Large Area Survey (ATLAS) has surveyed 7 square degrees of sky around the Chandra Deep Field South and the European Large Area ISO Survey-South 1 fields at 1.4 GHz. ATLAS aims to reach a uniform sensitivity of 10 ˘Jy beam−1 rms over the entire region with first data release currently reaching ∼ 30 ˘Jy beam−1 rms. Here we present 466 new spectroscopic redshifts for radio sources in ATLAS as part of our optical follow-up programme. Of the 466 radio sources with new spectroscopic redshifts, 142 have star-forming optical spectra, 282 show evidence for active galactic nuclei (AGN) in their optical spectra, 10 have stellar spectra and 32 have spectra revealing redshifts, but with insufficient features to classify. We compare our spectroscopic classifications with two mid-infrared diagnostics and find them to be in broad agreement. We also construct the radio luminosity function for star-forming galaxies to z = 0.5 and for AGN to z = 0.8. The radio luminosity function for star-forming galaxies appears to be in good agreement with previous studies. The radio luminosity function for AGN appears higher than previous studies of the local AGN radio luminosity function. We explore the possibility of evolution, cosmic variance and classification techniques affecting the AGN radio luminosity function. ATLAS is a pathfinder for the forthcoming Evolution Map of the Universe (EMU) survey and the data presented in this paper will be used to guide EMU's survey design and early science papers. [ABSTRACT FROM AUTHOR]
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- 2012
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6. ATLAS, and Wide-Angle Tail Galaxies in ATLAS.
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Mao, Minnie, Sharp, Rob, Saikia, D., Norris, Ray, Johnston-Hollitt, Melanie, Middelberg, Enno, and Lovell, Jim
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GALAXY clusters , *RADIO telescopes , *REDSHIFT , *ASTRONOMICAL observations , *ASTRONOMICAL photometry , *COSMIC magnetic fields , *RADIO galaxies - Abstract
Using the Australia Telescope Compact Array (ATCA), ATLAS (Australia Telescope Large Area Survey) is imaging two fields totalling 7 square degrees down to 10 μJy beam at 1.4 GHz. We have found 6 wide-angle tail galaxies (WATs), 4 of which have sufficient data to identify associated galaxy overdensities. The largest WAT, at a red-shift of 0.22, appears to be associated with an overdensity of galaxies that is spread over an unusually large extent of 12 Mpc, with a velocity range of 4500 km s. Here we present the WATs in ATLAS and discuss the implications of these observations for future large-scale radio surveys such as ASKAP-EMU. [ABSTRACT FROM AUTHOR]
- Published
- 2011
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7. Wide-angle tail galaxies in ATLAS.
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Mao, Minnie Y., Sharp, Rob, Saikia, D. J., Norris, Ray P., Johnston-Hollitt, Melanie, Middelberg, Enno, and Lovell, Jim E. J.
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RADIO sources (Astronomy) , *SPECTROGRAPHS , *REDSHIFT , *ASTRONOMICAL photometry , *SPACE telescopes , *GALAXIES - Abstract
We present radio images of a sample of six wide-angle tail (WAT) radio sources, identified in the Australia Telescope Large Area Survey 1.4-GHz radio survey, and new spectroscopic redshifts for four of these sources. These WATs are in the redshift range of 0.3762, and we find evidence of galaxy overdensities in the vicinity of four of the WATs from either spectroscopic or photometric redshifts. We also present follow-up spectroscopic observations of the area surrounding the largest WAT, S1189, which is at a redshift of ∼0.22. The spectroscopic observations, taken using the AAOmega spectrograph on the Anglo-Australian Telescope, show an overdensity of galaxies at this redshift. The galaxies are spread over an unusually large area of ∼12 Mpc with a velocity spread of ∼4500 km s−1. This large-scale structure includes a highly asymmetric Fanaroff–Riley type I radio galaxy and also appears to host a radio relic. It may represent an unrelaxed system with different sub-structures interacting or merging with one another. We discuss the implications of these observations for future large-scale radio surveys. [ABSTRACT FROM AUTHOR]
- Published
- 2010
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8. A pilot survey for KX QSOs in the UKIDSS Ultra Deep Survey Field.
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Smail, Ian, Sharp, Rob, Swinbank, A. M., Akiyama, M., Ueda, Y., Foucaud, S., Almaini, O., and Croom, S.
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QUASARS , *SURVEYS , *INFRARED radiation , *ASTRONOMY , *METAPHYSICAL cosmology - Abstract
We have undertaken a pilot survey for faint quasi-stellar objects (QSOs) in the UKIRT Infrared Deep Survey (UKIDSS) Ultra Deep Survey (UDS) Field using the KX selection technique. These observations exploit the very deep near-infrared and optical imaging of this field from United Kingdom Infrared Telescope (UKIRT) and Subaru to select candidate QSOs based on their VJK colours and morphologies. We determined redshifts for 426 candidates using the AAOmega spectrograph on the Anglo-Australian Telescope in service time. We identify 17 QSOs in this pilot survey at z= 1.57–3.29. We combine our sample with an X-ray-selected sample of QSOs in the same field (a large fraction of which also comply with our KX selection) to constrain the surface density of QSOs with K≤ 20, deriving limits on the likely surface density of 85–150 deg−2. We use the good image quality available from our near-infrared imaging to detect a spatially extended component of the QSO light which probably represents the host galaxies. We also use our sample to investigate routes to improve the selection of KX QSOs at faint limits in the face of the significant contamination by compact, foreground galaxies. The brightest examples from our combined QSO sample will be used in conjunction with a large Very Large Telescope VIMOS spectroscopic survey of high-redshift galaxies in this region to study the structures inhabited by gas, galaxies and growing supermassive black holes at high redshifts in the UKIDSS UDS. [ABSTRACT FROM AUTHOR]
- Published
- 2008
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9. Integral-field spectroscopy of Centaurus A nucleus.
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Krajnovič, Davor, Sharp, Rob, and Thatte, Niranjan
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CENTAURUS (Constellation) , *GALAXIES , *ASTRONOMICAL observations , *SPECTRUM analysis , *INFRARED imaging , *KINEMATICS , *DYNAMICS - Abstract
We report integral-field spectroscopic observations with the Cambridge Infrared Panoramic Survey Spectrograph (CIRPASS) mounted on the Gemini South telescope of the nucleus of the nearby galaxy NGC 5128 (Centaurus A). We detect two-dimensional distributions of the following emission lines: [P ii], [Fe ii] and Paschen β. We compare our observations with previously published radio observations using the Very Large Array (VLA) and archival space-based near-infrared imaging using the Hubble Space Telescope ( HST/NICMOS) and find similar features, as well as a region of high continuum coinciding with the jet (and its N1 knot) at about 2 arcsec north-east of the nucleus, possibly related to jet-induced star formation. We use the [Fe ii]/[P ii] ratio to probe the ionization mechanism, which suggests that with increasing radius shocks play an increasingly important role. We extract spatially resolved 2D kinematics of Paβ and [Fe ii] emission lines. All emission-line regions are part of the same kinematic structure which shows a twist in the zero-velocity curve beyond ∼1 arcsec (for both Paβ and [Fe ii]). The kinematics of the two emission lines are similar, but the Paβ velocity gradient is steeper in the centre while the velocity dispersion is low everywhere. The velocity dispersion of the [Fe ii] emission is relatively high featuring a plateau, approximately oriented in the same way as the central part of the warped disc. We use 2D kinematic information to test the hypothesis that the ionized gas is distributed in a circularly rotating disc. Assuming simple disc geometry we estimate the mass of the central black hole using Paβ kinematics, which is consistent with being distributed in a circularly rotating disc. We obtain , for and , excluding the M•–σ relation prediction at a 3σ confidence level, which is in good agreement with previous studies. [ABSTRACT FROM AUTHOR]
- Published
- 2007
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10. Critical Perspectives on Journalistic Beliefs and Actions: Global Experiences.
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Sharp, Rob
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JOURNALISTS , *NONFICTION - Published
- 2020
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11. Rap on the run.
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Sharp, Rob
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HIP-hop culture ,UNITED States presidential elections - Abstract
The article presents a profile of Nehanda Abiodun, an American promoter of hip-hop music and culture ,wanted by the U.S. Federal Bureau of Investigation. Resident in Cuba, Abiodun is a suspect in a number of crimes committed in the U.S. in the 1970s and 1980s. Abiodun discusses a number of issues including attitudes toward race, her work with Cuban rappers and the 2008 U.S. presidential election.
- Published
- 2008
12. Britain's hidden art.
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Sharp, Rob
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ART , *COLLECTORS & collecting , *ART museums , *GOVERNMENT policy - Abstract
The article discusses the fact that a significant number of art objects in Great Britain are in the hands of private collectors and thus unavailable for public viewing. The large amounts of money spent by collectors for artwork and its impact on the purchasing policies of British museums is examined. British government policy for the funding of art museums is criticized.
- Published
- 2007
13. Benoît Maire.
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Sharp, Rob
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SCULPTURE exhibitions , *EXHIBITIONS - Abstract
The article reviews an art exhibition held at the David Roberts Art Foundation art space in London, England from March 15-May 11, 2013 featuring sculptures by artist Benoît Maire.
- Published
- 2013
14. Lisson Gallery.
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Sharp, Rob
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ART exhibitions , *EXHIBITIONS - Abstract
The article reviews an art exhibition held at the Lisson Gallery in London, England from January 30-March 9, 2013 featuring artworks by artist Richard Wentworth.
- Published
- 2013
15. Ali Banisadr.
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Sharp, Rob
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21ST century painting , *EXHIBITIONS , *ART exhibitions - Abstract
The article reviews an unnamed art exhibition that featured various paintings and other works by the Iran-raised and New York City-based artist Ali Banisadr, held at the Blain/Southern gallery, located in London, England, from February 11th through March 21, 2015.
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- 2015
16. Steve McQueen.
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Sharp, Rob
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21ST century art exhibitions , *INSTALLATION art exhibitions , *EXHIBITIONS - Abstract
The article reviews the art exhibition "Ashes," which will feature a video installation by the British contemporary artist and filmmaker Steve McQueen, held at the Thomas Dane Gallery in London, England, from October 14th through November 15, 2014.
- Published
- 2015
17. The Knee-Fix study: study protocol for a randomised controlled trial evaluating cemented and cementless components in total knee arthroplasty.
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Tay, Mei Lin, Zeng, Nina, Holland, Sherina, Bayan, Ali, Farrington, Bill J., van Rooyen, Rupert, Sharp, Rob, Elliott, Robert S. J., Walker, Matthew L., and Young, Simon W.
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KNEE , *TOTAL knee replacement , *RANDOMIZED controlled trials , *POROUS metals , *PATIENT satisfaction , *CEMENT - Abstract
Background: Total knee arthroplasty (TKA) is an effective procedure for patients with a variety of knee conditions. The main cause of aseptic TKA failure is implant loosening, which has been linked to poor cement mantle quality. Cementless components were introduced to offer better longer-term biological fixation through osseointegration; however, early designs led to increased rate of revision due to a lack of initial press-fit and bony ingrowth. Newer highly porous metal designs may alleviate this issue but randomised data of fully uncemented TKA (tibial, femoral, patella) is lacking. The aim of the Knee-Fix study is to investigate the long-term implant survival and patient outcomes of fully uncemented compared with cemented fixation in TKA. Our study hypothesis was that uncemented TKA would be as clinically reliable and durable as the gold-standard cemented TKA. Methods: The Knee-Fix study is a two-arm, single-blinded, non-inferiority randomised controlled trial with 160 patients in each arm and follow-up at 6 weeks, 6 months, 12 months, 24 months, 5 years and 10 years. The primary outcome of interest is implant fixation, which will be measured by assessment of postoperative progressive radiolucencies with the Knee Society Total Knee Arthroplasty Roentgenographic Evaluation and Scoring System. Secondary outcome measures are patient-reported outcomes, measured using Oxford Knee Score (OKS), International Knee Society System (IKSS), Forgotten Joint Score-12 (FJS-12), EuroQol (EQ-5D-5L), VAS Pain, Patient Satisfaction Score and Net Promoter Score. Discussion: While cemented fixation remains the gold standard, a growing proportion of TKA are now implanted cementless. Highly porous metal cementless components for TKA can offer several benefits including potentially improved biological fixation; however, long-term outcomes need further investigation. This prospective study will help discern long-term differences between the two techniques. Trial registration: Australian New Zealand Clinical Trials Registry ACTRN12616001624471. Registered trial name: Knee-Fix study (Cemented vs Uncemented Total Knee Replacement). Registered on 24 November 2016. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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18. Spanish Monastery Is Artfully Restored With Bursts of Color.
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SHARP, ROB
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MONASTERIES , *PRESERVATION of monasteries - Abstract
The article discusses the permanent exhibition of paintings by Irish-American artist Sean Scully in the monastery of Santa Cecilia in Montserrat, Spain, installed as part of the recently completed restoration of the monastery, noting that Scully also advised on various aspects of the restoration.
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- 2015
19. Billy Childish.
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Sharp, Rob
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21ST century art exhibitions , *PAINTING exhibitions , *EXHIBITIONS - Abstract
The article reviews an unnamed art exhibition that featured various paintings and other works by the musician, poet and painter Billy Childish, held at the Carl Freedman Gallery, located in London, England, from September 18th through October 26, 2013.
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- 2013
20. Carlos/Ishikawa.
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Sharp, Rob
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ART exhibitions , *EXHIBITIONS - Abstract
The article reviews the art exhibition "An Escalator Can Never Break, It Can Only Become Stairs" held at the Carlos/Ishikawa art gallery in London, England from January 24-March 2, 2013 featuring artworks by artist Steve Bishop.
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- 2013
21. Jannis Kounellis.
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Sharp, Rob
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SCULPTURE exhibitions , *EXHIBITIONS - Abstract
The article reviews an art exhibition held at the Parasol Unit gallery in London, England from November 28, 2012-February 23, 2013 featuring sculptures by artist Jannis Kounellis.
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- 2013
22. Sachin Kaeley.
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Sharp, Rob
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PAINTING exhibitions , *EXHIBITIONS - Abstract
The article reviews an art exhibition held at the Seventeen gallery in London, England from January 10-February 16, 2013 featuring paintings by artist Sachin Kaeley.
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- 2013
23. Elmgreen & Dragset.
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Sharp, Rob
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ART exhibitions - Abstract
The article reviews the art exhibition "Harvest" held at the Victoria Miro gallery in London, England from September 21-November 10, 2012 featuring works by the artist duo Elmgreen & Dragset.
- Published
- 2013
24. SEEDS OF THE FUTURE.
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Sharp, Rob
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TRANSGENIC seed banks , *SEED storage , *PRAIRIES ,MILLENNIUM Seed Bank (West Sussex, England) - Abstract
The article discusses the Millennium Seed Bank (MSB) in West Sussex, England, a facility run by the Royal Botanic Gardens, Kew, in London, England. It notes that the facility is used to freeze and store seeds of various plant species. The author comments that samples have been gathered from the Northern tallgrass prairie ecosystem of the U.S.
- Published
- 2012
25. Acetabular impaction grafting in total hip replacement.
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Rigby, Michael, Kenny, Paddy J., Sharp, Rob, Whitehouse, Sarah L., Gie, Graham A., and Timperley, John A.
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BONE grafting , *HIP surgery , *TOTAL hip replacement , *ANALYSIS of variance , *CHI-squared test , *CONFIDENCE intervals , *EPIDEMIOLOGY , *FISHER exact test , *HOMOGRAFTS , *LIQUIDS , *PROPERTIES of matter , *HEALTH outcome assessment , *REOPERATION , *STATISTICS , *SURGICAL complications , *SURVIVAL analysis (Biometry) , *DATA analysis , *TREATMENT effectiveness , *DATA analysis software ,ACETABULUM surgery - Abstract
Background and purpose: Acetabular impaction grafting has been shown to be very effective, but concerns regarding its suitability for larger defects have been highlighted. We report the use of this technique in a large cohort of patients, and address possible limitations of the technique. Methods: We investigated a consecutive group of 339 cases of impaction grafting of the cup with morcellised impacted allograft bone for survivorship and mechanisms for early failure. Results: Kaplan Meier survival was 89.1% (95% CI 83.2 to 95.0%) at 5.8 years for revision for any reason, and 91.6% (95% CI 85.9 to 97.3%) for revision for aseptic loosening of the cup. Of the 15 cases revised for aseptic cup loosening, nine were large rim mesh reconstructions, two were fractured Kerboull-Postel plates, two were migrating cages, one was a medial wall mesh failure and one had been treated by impaction alone. Interpretation: In our series, results were disappointing where a large rim mesh or significant reconstruction was required. In light of these results, our technique has changed in that we now use predominantly larger chips of purely cancellous bone, 8-10 mm3 in size, to fill the cavity and larger diameter cups to better fill the aperture of the reconstructed acetabulum. In addition we now make greater use of i) implants made of a highly porous in-growth surface to constrain allograft chips and ii) bulk allografts combined with cages and morcellised chips in cases with very large segmental and cavitary defects. [ABSTRACT FROM AUTHOR]
- Published
- 2011
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26. Hamish Fulton.
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Sharp, Rob
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21ST century British art , *EXHIBITIONS , *ART exhibitions - Abstract
The article reviews an exhibition featuring works by the British artist Hamish Fulton, on view at the Maureen Paley gallery in London, England from July 20 until August 25, 2013.
- Published
- 2013
27. Quantifying the effects of spatial resolution and noise on galaxy metallicity gradients.
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Acharyya, Ayan, Krumholz, Mark R, Federrath, Christoph, Kewley, Lisa J, Goldbaum, Nathan J, and Sharp, Rob
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INTEGRAL field spectroscopy , *MILKY Way , *SIGNAL-to-noise ratio , *GALACTIC evolution , *GALAXIES - Abstract
Metallicity gradients are important diagnostics of galaxy evolution, because they record the history of events such as mergers, gas inflow, and star formation. However, the accuracy with which gradients can be measured is limited by spatial resolution and noise, and hence, measurements need to be corrected for such effects. We use high-resolution (∼20 pc) simulation of a face-on Milky Way mass galaxy, coupled with photoionization models, to produce a suite of synthetic high-resolution integral field spectroscopy (IFS) datacubes. We then degrade the datacubes, with a range of realistic models for spatial resolution (2−16 beams per galaxy scale length) and noise, to investigate and quantify how well the input metallicity gradient can be recovered as a function of resolution and signal-to-noise ratio (SNR) with the intention to compare with modern IFS surveys like MaNGA and SAMI. Given appropriate propagation of uncertainties and pruning of low SNR pixels, we show that a resolution of 3–4 telescope beams per galaxy scale length is sufficient to recover the gradient to ∼10–20 per cent uncertainty. The uncertainty escalates to ∼60 per cent for lower resolution. Inclusion of the low SNR pixels causes the uncertainty in the inferred gradient to deteriorate. Our results can potentially inform future IFS surveys regarding the resolution and SNR required to achieve a desired accuracy in metallicity gradient measurements. [ABSTRACT FROM AUTHOR]
- Published
- 2020
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28. Antony Gormley.
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Sharp, Rob
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METAL sculpture , *21ST century art exhibitions , *EXHIBITIONS - Abstract
The article reviews an exhibition by artist Antony Gormley at the gallery White Cube in London, England from November 28, 2012 - February 10, 2013.
- Published
- 2013
29. Thomas Houseago.
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Sharp, Rob
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SCULPTURE exhibitions , *21ST century art exhibitions , *EXHIBITIONS - Abstract
The article reviews an unnamed art exhibition that featured various sculptures and other works by the contemporary U.S.-based British artist Thomas Houseago, held at the Hauser & Wirth gallery located in London, England, from September 7th through October 27, 2012.
- Published
- 2012
30. The SAMI Galaxy Survey: Data Release One with emission-line physics value-added products.
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Green, Andrew W., Croom, Scott M., Scott, Nicholas, Cortese, Luca, Medling, Anne M., D'Eugenio, Francesco, Bryant, Julia J., Bland-Hawthorn, Joss, Allen, J. T., Sharp, Rob, I-Ting Ho, Groves, Brent, Drinkwater, Michael J., Mannering, Elizabeth, Harischandra, Lloyd, de Sande, Jesse van, Thomas, Adam D., O'Toole, Simon, McDermid, Richard M., and Minh Vuong
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GALACTIC redshift , *FIELD emission , *COSMIC dust , *GALAXY spectra , *STAR formation - Abstract
We present the first major release of data from the SAMI Galaxy Survey. This data release focuses on the emission-line physics of galaxies. Data Release One includes data for 772 galaxies, about 20 per cent of the full survey. Galaxies included have the redshift range 0.004 < z < 0.092, a large mass range (7.6 < logM*/M☉ < 11.6), and star formation rates of ∼10-4 to ∼101M☉ yr-1. For each galaxy, we include two spectral cubes and a set of spatially resolved 2D maps: single- and multi-component emission-line fits (with dust-extinction corrections for strong lines), local dust extinction, and star formation rate. Calibration of the fibre throughputs, fluxes, and differential atmospheric refraction has been improved over the Early Data Release. The data have average spatial resolution of 2.16 arcsec (full width at half-maximum) over the 15 arcsec diameter field of view and spectral (kinematic) resolution of R = 4263 (σ = 30 km s-1) around Hα. The relative flux calibration is better than 5 per cent, and absolute flux calibration has an rms of 10 per cent. The data are presented online through the Australian Astronomical Observatory's Data Central. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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31. Discovery of a z = 0.65 post-starburst BAL quasar in the DES supernova fields.
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Mudd, Dale, Martini, Paul, Suk Sien Tie, Lidman, Chris, McMahon, Richard, Banerji, Manda, Davis, Tamara, Peterson, Bradley, Sharp, Rob, Seymour, Nicholas, Childress, Michael, Lewis, Geraint, Tucker, Brad, Fang Yuan, Abbot, Tim, Abdalla, Filipe, Allam, Sahar, Benoit-Lévy, Aurélien, Bertin, Emmanuel, and Brooks, David
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STARBURSTS , *RADIATION absorption , *GALAXY spectra , *SPECTRA of quasars , *ASTRONOMICAL spectroscopy - Abstract
We present the discovery of a z = 0.65 low-ionization broad absorption line (LoBAL) quasar in a post-starburst galaxy in data from the Dark Energy Survey (DES) and spectroscopy from the Australian Dark Energy Survey (OzDES). LoBAL quasars are a minority of all BALs, and rarer still is that this object also exhibits broad Fe II (an FeLoBAL) and Balmer absorption. This is the first BAL quasar that has signatures of recently truncated star formation, which we estimate ended about 40 Myr ago. The characteristic signatures of an FeLoBAL require high column densities, which could be explained by the emergence of a young quasar from an early, dust-enshrouded phase, or by clouds compressed by a blast wave. The age of the starburst component is comparable to estimates of the lifetime of quasars, so if we assume the quasar activity is related to the truncation of the star formation, this object is better explained by the blast wave scenario. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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32. LZIFU: an emission-line fitting toolkit for integral field spectroscopy data.
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Ho, I-Ting, Medling, Anne, Groves, Brent, Rich, Jeffrey, Rupke, David, Hampton, Elise, Kewley, Lisa, Bland-Hawthorn, Joss, Croom, Scott, Richards, Samuel, Schaefer, Adam, Sharp, Rob, and Sweet, Sarah
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EMISSION-line galaxies , *MACHINE-shop practice , *INTEGRAL field spectroscopy , *SPECTROGRAPHS , *ROBUST control - Abstract
We present lzifu (LaZy-IFU), an idl toolkit for fitting multiple emission lines simultaneously in integral field spectroscopy (IFS) data. lzifu is useful for the investigation of the dynamical, physical and chemical properties of gas in galaxies. lzifu has already been applied to many world-class IFS instruments and large IFS surveys, including the Wide Field Spectrograph, the new Multi Unit Spectroscopic Explorer (MUSE), the Calar Alto Legacy Integral Field Area (CALIFA) survey, the Sydney-Australian-astronomical-observatory Multi-object Integral-field spectrograph (SAMI) Galaxy Survey. Here we describe in detail the structure of the toolkit, and how the line fluxes and flux uncertainties are determined, including the possibility of having multiple distinct kinematic components. We quantify the performance of lzifu, demonstrating its accuracy and robustness. We also show examples of applying lzifu to CALIFA and SAMI data to construct emission line and kinematic maps, and investigate complex, skewed line profiles presented in IFS data. The code is made available to the astronomy community through github. lzifu will be further developed over time to other IFS instruments, and to provide even more accurate line and uncertainty estimates. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
33. The SAMI Galaxy Survey: extraplanar gas, galactic winds and their association with star formation history.
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I-Ting Ho, Medling, Anne M., Bland-Hawthorn, Joss, Groves, Brent, Kewley, Lisa J., Kobayashi, Chiaki, Dopita, Michael A., Leslie, Sarah K., Sharp, Rob, Allen, James T., Bourne, Nathan, Bryant, Julia J., Cortese, Luca, Croom, Scott M., Dunne, Loretta, Fogarty, L. M. R., Goodwin, Michael, Green, Andy W., Konstantopoulos, Iraklis S., and Lawrence, Jon S.
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STAR formation , *INTEGRAL field spectroscopy , *GALACTIC dynamics , *GALACTIC evolution , *GALAXY formation , *STARBURSTS - Abstract
We investigate a sample of 40 local, main-sequence, edge-on disc galaxies using integral field spectroscopy with the Sydney-AAO Multi-object Integral field spectrograph (SAMI) Galaxy Survey to understand the link between properties of the extraplanar gas and their host galaxies. The kinematics properties of the extraplanar gas, including velocity asymmetries and increased dispersion, are used to differentiate galaxies hosting large-scale galactic winds from those dominated by the extended diffuse ionized gas. We find rather that a spectrum of diffuse gas-dominated to wind-dominated galaxies exist. The wind-dominated galaxies span a wide range of star formation rates (SFRs; -1 ≲ log?(SFR/M⊙?yr-1) ≲ 0.5) across the whole stellar mass range of the sample (8.5 ≲ log (M*/M⊙) ≲ 11). The wind galaxies also span a wide range in SFR surface densities (10-3-10-1.5?M⊙?yr-1?kpc-2) that is much lower than the canonical threshold of 0.1?M⊙?yr-1?kpc-2. The wind galaxies on average have higher SFR surface densities and higher HδA values than those without strong wind signatures. The enhanced HδA indicates that bursts of star formation in the recent past are necessary for driving large-scale galactic winds. We demonstrate with Sloan Digital Sky Survey data that galaxies with high SFR surface density have experienced bursts of star formation in the recent past. Our results imply that the galactic winds revealed in our study are indeed driven by bursts of star formation, and thus probing star formation in the time domain is crucial for finding and understanding galactic winds. [ABSTRACT FROM AUTHOR]
- Published
- 2016
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34. Simulations of the OzDES AGN reverberation mapping project.
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King, Anthea L., Martini, Paul, Davis, Tamara M., Denney, K. D., Kochanek, C. S., Peterson, Bradley M., Skielboe, Andreas, Vestergaard, Marianne, Huff, Eric, Watson, Darach, Banerji, Manda, McMahon, Richard, Sharp, Rob, and Lidman, C.
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GALACTIC nuclei , *REDSHIFT , *PROJECT management , *DARK energy , *COMPUTER simulation , *SUPERNOVAE - Abstract
As part of the Australian spectroscopic dark energy survey (OzDES) we are carrying out a large-scale reverberation mapping study of ≥500 quasars over five years in the 30 deg2 area of the Dark Energy Survey (DES) supernova fields. These quasars have redshifts ranging up to 4 and have apparent AB magnitudes between 16.8 mag < r < 22.5 mag. The aim of the survey is to measure time lags between fluctuations in the quasar continuum and broad emission-line fluxes of individual objects in order to measure black hole masses for a broad range of active galactic nuclei (AGN) and constrain the radius–luminosity (R–L) relationship. Here we investigate the expected efficiency of the OzDES reverberation mapping campaign and its possible extensions. We expect to recover lags for ∼35–45 per cent of the quasars. AGN with shorter lags and greater variability are more likely to yield a lag measurement, and objects with lags ≲6 months or ∼1 yr are expected to be recovered the most accurately. The baseline OzDES reverberation mapping campaign is predicted to produce an unbiased measurement of the R–L relationship parameters for H β, Mg II λ2798, and C iv λ1549. Extending the baseline survey by either increasing the spectroscopic cadence, extending the survey season, or improving the emission-line flux measurement accuracy will significantly improve the R–L parameter constraints for all broad emission lines. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
35. The accretion histories of brightest cluster galaxies from their stellar population gradients.
- Author
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Oliva-Altamirano, Paola, Brough, Sarah, Jimmy, Tran, Kim-Vy, Couch, Warrick J., McDermid, Richard M., Lidman, Chris, von der Linden, Anja, and Sharp, Rob
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ACCRETION (Astrophysics) , *GALAXY clusters , *STELLAR populations , *STELLAR rotation , *STELLAR evolution - Abstract
We analyse the spatially resolved stellar populations of nine local (z < 0.1) Brightest Cluster Galaxies (BCGs) observed with VIMOS in Integral Field Unit mode. Our sample is composed of seven slow-rotating and two fast-rotating BCGs. We do not find a connection between stellar kinematics and stellar populations in this small sample. The BCGs have shallow metallicity gradients (median Δ[Fe/H]=-0.11 ± 0.1), high central metallicities (median [Fe/H][α/Fe] = 0 = 0.13 ± 0.07), and a wide range of central ages (from 5 to 15 Gyr). We propose that the reason for this is diverse evolutionary paths in BCGs. 67 per cent of the sample (6/9) show ~7 Gyr old central ages, which reflects an active accretion history, and 33 per cent of the sample (3/9) have central ages older than 11 Gyr, which suggest no star formation since z = 2. The BCGs show similar central stellar populations and stellar population gradients to early-type galaxies of similar mass (Mdyn > 1011.3 M☉) from the ATLAS3D survey (median [Z/H] = 0.04 ± 0.07, Δ[Z/H] = -0.19 ± 0.1). However, massive early-type galaxies from ATLAS3D have consistently old ages (median Age = 12.0 ± 3.8 Gyr). We also analyse the close massive companion galaxies of two of the BCGs. These galaxies have similar stellar populations to their respective BCGs. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
36. IFU observations of luminous type II AGN - I. Evidence for ubiquitous winds.
- Author
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McElroy, Rebecca, Croom, Scott M., Pracy, Michael, Sharp, Rob, I.-Ting Ho, and Medling, Anne M.
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GALAXY formation , *GALACTIC evolution , *IONIZATION (Atomic physics) , *ASTRONOMICAL observations , *ASTROPHYSICS - Abstract
We present observations of 17 luminous (log(L[O III]/L☉) > 8.7) local (z <0.11) type II AGN. Our aim is to investigate the prevalence and nature of AGN-driven outflows in these galaxies by combining kinematic and ionization diagnostic information. We use non-parametric methods (e.g. W80, the width containing 80 per cent of the line flux) to assess the line widths in the central regions of our targets. The maximum values of W80 in each galaxy are in the range 400-1600km s-1, with a mean of 790 ± 90 km s-1. Such high velocities are strongly suggestive that these AGN are driving ionized outflows. Multi-Gaussian fitting is used to decompose the velocity structure in our galaxies. 14/17 of our targets require three separate kinematic components in the ionized gas in their central regions. The broadest components of these fits have FWHM = 530-2520 km s-1, with a mean value of 920 ± 50 km s-1. By simultaneously fitting both the Hβ/[O III] and Hα/[N II] complexes, we construct ionization diagnostic diagrams for each component. 13/17 of our galaxies show a significant (>95 per cent) correlation between the [NII]/Hα ratio and the velocity dispersion of the gas. Such a correlation is the natural consequence of a contribution to the ionization from shock excitation and we argue that this demonstrates that the outflows from these AGN are directly impacting the surrounding ISM within the galaxies. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
37. The SAMI Galaxy Survey: shocks and outflows in a normal star-forming galaxy.
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Ho, I-Ting, Kewley, Lisa J., Dopita, Michael A., Medling, Anne M., Allen, J. T., Bland-Hawthorn, Joss, Bloom, Jessica V., Bryant, Julia J., Croom, Scott M., Fogarty, L. M. R., Goodwin, Michael, Green, Andy W., Konstantopoulos, Iraklis S., Lawrence, Jon S., López-Sánchez, Á. R., Owers, Matt S., Richards, Samuel, and Sharp, Rob
- Subjects
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STAR formation , *BIPOLAR outflows (Astrophysics) , *POTENTIAL theory (Physics) , *GALACTIC dynamics , *GALACTIC evolution - Abstract
We demonstrate the feasibility and potential of using large integral field spectroscopic surveys to investigate the prevalence of galactic-scale outflows in the local Universe. Using integral field data from the Sydney-AAO Multi-object Integral field spectrograph (SAMI) and the Wide Field Spectrograph, we study the nature of an isolated disc galaxy, SDSS J090005.05+000446.7 (z = 0.053 86). In the integral field data sets, the galaxy presents skewed line profiles changing with position in the galaxy. The skewed line profiles are caused by different kinematic components overlapping in the line-of-sight direction. We perform spectral decomposition to separate the line profiles in each spatial pixel as combinations of (1) a narrow kinematic component consistent with H ii regions, (2) a broad kinematic component consistent with shock excitation, and (3) an intermediate component consistent with shock excitation and photoionization mixing. The three kinematic components have distinctly different velocity fields, velocity dispersions, line ratios, and electron densities. We model the line ratios, velocity dispersions, and electron densities with our mappings iv shock and photoionization models, and we reach remarkable agreement between the data and the models. The models demonstrate that the different emission line properties are caused by major galactic outflows that introduce shock excitation in addition to photoionization by star-forming activities. Interstellar shocks embedded in the outflows shock-excite and compress the gas, causing the elevated line ratios, velocity dispersions, and electron densities observed in the broad kinematic component. We argue from energy considerations that, with the lack of a powerful active galactic nucleus, the outflows are likely to be driven by starburst activities. Our results set a benchmark of the type of analysis that can be achieved by the SAMI Galaxy Survey on large numbers of galaxies. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
38. The SAMI Pilot Survey: the kinematic morphology–density relation in Abell 85, Abell 168 and Abell 2399.
- Author
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Fogarty, L. M. R., Scott, Nicholas, Owers, Matt S., Brough, S., Croom, Scott M., Pracy, Michael B., Houghton, R. C. W., Bland-Hawthorn, Joss, Colless, Matthew, Davies, Roger L., Jones, D. Heath, Allen, J. T., Bryant, Julia J., Goodwin, Michael, Green, Andrew W., Konstantopoulos, Iraklis S., Lawrence, J. S., Richards, Samuel, Cortese, Luca, and Sharp, Rob
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GALAXY clusters , *KINEMATICS , *SPECTROGRAPHS , *ANGULAR momentum (Nuclear physics) , *SPECTRAL imaging , *ELLIPTICAL galaxies - Abstract
We examine the kinematic morphology of early-type galaxies (ETGs) in three galaxy clusters Abell 85, 168 and 2399. Using data from the Sydney-AAO Multi-object Integral field spectrograph we measure spatially resolved kinematics for 79 ETGs in these clusters. We calculate λR, a proxy for the projected specific stellar angular momentum, for each galaxy and classify the 79 ETGs in our samples as fast or slow rotators. We calculate the fraction of slow rotators in the ETG populations (fSR) of the clusters to be 0.21 ± 0.08, 0.08 ± 0.08 and 0.12 ± 0.06 for Abell 85, 168 and 2399, respectively, with an overall fraction of 0.15 ± 0.04. These numbers are broadly consistent with the values found in the literature, confirming recent work asserting that the fraction of slow rotators in the ETG population is constant across many orders of magnitude in global environment. We examine the distribution of kinematic classes in each cluster as a function of environment using the projected density of galaxies: the kinematic morphology–density relation. We find that in Abell 85 fSR increases in higher density regions but in Abell 168 and 2399 this trend is not seen. We examine the differences between the individual clusters to explain this. In addition, we find slow rotators on the outskirts of two of the clusters studied, Abell 85 and 2399. These galaxies reside in intermediate to low density regions and have clearly not formed at the centre of a cluster environment. We hypothesize that they formed at the centres of groups and are falling into the clusters for the first time. [ABSTRACT FROM PUBLISHER]
- Published
- 2014
- Full Text
- View/download PDF
39. ANGULAR MOMENTA, DYNAMICAL MASSES, AND MERGERS OF BRIGHTEST CLUSTER GALAXIES.
- Author
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Jimmy, Tran, Kim-Vy, Brough, Sarah, Gebhardt, Karl, Linden, Anja von der, Couch, Warrick J., and Sharp, Rob
- Subjects
- *
VERY Large Telescope (Chile) , *VERY large telescopes , *ASTRONOMICAL photometry , *STELLAR rotation , *REDSHIFT - Abstract
Using the VIMOS integral field unit (IFU) spectrograph on the Very Large Telescope, we have spatially mapped the kinematic properties of 10 nearby brightest cluster galaxies (BCGs) and 4 BCG companion galaxies located within a redshift of z = 0.1. In the hierarchical formation model, these massive galaxies (1010.5M☼ < Mdyn < 1011.9M☼) are expected to undergo more mergers than lower mass galaxies, and simulations show that dry minor mergers can remove angular momentum. We test whether BCGs have low angular momenta by using the λRe parameter developed by the SAURON and ATLAS3D teams and combine our kinematics with Sloan Digital Sky Survey photometry to analyze the BCGs' merger status. We find that 30% (3/10) of the BCGs and 100% of the companion galaxies (4/4) are fast rotators as defined by the ATLAS3D criteria. Our fastest rotating BCG has a λRe = 0.35 ± 0.05. We increase the number of BCGs analyzed from 1 in the combined SAURON and ATLAS3D surveys to 11 BCGs total and find that above Mdyn ∼ 11.5 M☼, virtually all galaxies, regardless of environment, are slow rotators. To search for signs of recent merging, we analyze the photometry of each system and use the G – M20 selection criteria to identify mergers. We find that 40% ± 20% of our BCGs are currently undergoing or have recently undergone a merger (within 0.2 Gyr). Surprisingly, we find no correlation between galaxies with high angular momentum and morphological signatures of merging. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
- View/download PDF
40. The WiggleZ Dark Energy Survey: high-resolution kinematics of luminous star-forming galaxies.
- Author
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Wisnioski, Emily, Glazebrook, Karl, Blake, Chris, Wyder, Ted, Martin, Chris, Poole, Gregory B., Sharp, Rob, Couch, Warrick, Kacprzak, Glenn G., Brough, Sarah, Colless, Matthew, Contreras, Carlos, Croom, Scott, Croton, Darren, Davis, Tamara, Drinkwater, Michael J., Forster, Karl, Gilbank, David G., Gladders, Michael, and Jelliffe, Ben
- Subjects
- *
STELLAR luminosity function , *DARK energy , *SURVEYS , *KINEMATICS , *GALAXIES , *INTEGRAL field spectroscopy , *ASTRONOMICAL observations - Abstract
ABSTRACT We report evidence of ordered orbital motion in luminous star-forming galaxies at z∼ 1.3. We present integral field spectroscopy (IFS) observations, performed with the OH Suppressing InfraRed Imaging Spectrograph (OSIRIS) system, assisted by laser guide star adaptive optics on the Keck telescope, of 13 star-forming galaxies selected from the WiggleZ Dark Energy Survey. Selected via ultraviolet and [O ii] emission, the large volume of the WiggleZ survey allows the selection of sources which have comparable intrinsic luminosity and stellar mass to IFS samples at z > 2. Multiple 1-2 kpc size subcomponents of emission, or 'clumps', are detected within the Hα spatial emission which extends over 6-10 kpc in four galaxies, resolved compact emission ( r < 3 kpc) is detected in five galaxies and extended regions of Hα emission are observed in the remaining four galaxies. We discuss these data in the context of different snapshots in a merger sequence and/or the evolutionary stages of coalescence of star-forming regions in an unstable disc. We find evidence of ordered orbital motion in galaxies as expected from disc models and the highest values of velocity dispersion (σ > 100 km s−1) in the most compact sources. This unique data set reveals that the most luminous star-forming galaxies at z > 1 are gaseous unstable discs indicating that a different mode of star formation could be feeding gas to galaxies at z > 1, and lending support to theories of cold dense gas flows from the intergalactic medium. [ABSTRACT FROM AUTHOR]
- Published
- 2011
- Full Text
- View/download PDF
41. Planetary Nebulae towards the Galactic bulge - I. [O.
- Author
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Kovacevic, Anna V., Parker, Quentin A., Jacoby, George H., Sharp, Rob, Miszalski, Brent, and Frew, David J.
- Subjects
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PLANETARY nebulae , *GALACTIC bulges , *ASTRONOMICAL observations , *STELLAR luminosity function , *ASTROPHYSICS , *INTERSTELLAR medium , *TELESCOPES , *COMPACT objects (Astronomy) - Abstract
We present fluxes and angular diametres for 435 Planetary Nebulae (PNe) in the central region towards the Galactic bulge. Our sample is taken from the new discoveries of the MASH PN surveys as well as previously known PN. This sample accounts for 80 per cent of known PN in this region. Fluxes and diametres are measured from narrow-band imaging with the MOSAIC-II camera on the 4-m Blanco Telescope at the Cerro-Tololo Inter-American Observatory. This is the largest (60 deg), uniform survey of the inner Galactic bulge ever undertaken. 104 of the objects have measured , , or fluxes from the literature, which we use to undertake a detailed comparison to demonstrate the integrity of our new fluxes. Our independent measurements are in excellent agreement with the very best literature sources over two orders of magnitude, while maintaining good consistency over five orders of magnitude. The excellent resolution and sensitivity of our data allows not only for a robust set of homogenous PN fluxes, but provides greater detail into their intricate, otherwise undetermined morphologies. These new, extensive measurements significantly increase the sample of reliable fluxes for Galactic bulge PN making it a valuable resource and a prelude to the construction of our new Galactic bulge PN luminosity function (Paper II). [ABSTRACT FROM AUTHOR]
- Published
- 2011
- Full Text
- View/download PDF
42. The WiggleZ Dark Energy Survey: the selection function and z= 0.6 galaxy power spectrum.
- Author
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Blake, Chris, Brough, Sarah, Colless, Matthew, Couch, Warrick, Croom, Scott, Davis, Tamara, Drinkwater, Michael J., Forster, Karl, Glazebrook, Karl, Jelliffe, Ben, Jurek, Russell J., I-hui Li, Madore, Barry, Martin, Chris, Pimbblet, Kevin, Poole, Gregory B., Pracy, Michael, Sharp, Rob, Wisnioski, Emily, and Woods, David
- Subjects
- *
GALAXIES , *REDSHIFT , *COSMIC background radiation , *ASTROPHYSICAL radiation , *BARYONS - Abstract
We report one of the most accurate measurements of the three-dimensional large-scale galaxy power spectrum achieved to date, using 56 159 redshifts of bright emission-line galaxies at effective redshift from the WiggleZ Dark Energy Survey at the Anglo-Australian Telescope. We describe in detail how we construct the survey selection function allowing for the varying target completeness and redshift completeness. We measure the total power with an accuracy of approximately 5 per cent in wavenumber bands of . A model power spectrum including non-linear corrections, combined with a linear galaxy bias factor and a simple model for redshift-space distortions, provides a good fit to our data for scales . The large-scale shape of the power spectrum is consistent with the best-fitting matter and baryon densities determined by observations of the cosmic microwave background radiation. By splitting the power spectrum measurement as a function of tangential and radial wavenumbers, we delineate the characteristic imprint of peculiar velocities. We use these to determine the growth rate of structure as a function of redshift in the range , including a data point at with an accuracy of 20 per cent. Our growth rate measurements are a close match to the self-consistent prediction of the Λ cold dark matter model. The WiggleZ survey data will allow a wide range of investigations into the cosmological model, cosmic expansion and growth history, topology of cosmic structure and Gaussianity of the initial conditions. Our calculation of the survey selection function will be released at a future date via our website wigglez.swin.edu.au. [ABSTRACT FROM AUTHOR]
- Published
- 2010
- Full Text
- View/download PDF
43. The WiggleZ Dark Energy Survey: survey design and first data release.
- Author
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Drinkwater, Michael J., Jurek, Russell J., Blake, Chris, Woods, David, Pimbblet, Kevin A., Glazebrook, Karl, Sharp, Rob, Pracy, Michael B., Brough, Sarah, Colless, Matthew, Couch, Warrick J., Croom, Scott M., Davis, Tamara M., Forbes, Duncan, Forster, Karl, Gilbank, David G., Gladders, Michael, Jelliffe, Ben, Jones, Nick, and Li, I-hui
- Subjects
- *
ASTRONOMY , *GALAXIES , *REDSHIFT , *COSMIC background radiation , *ARTIFICIAL satellites - Abstract
The WiggleZ Dark Energy Survey is a survey of 240 000 emission-line galaxies in the distant Universe, measured with the AAOmega spectrograph on the 3.9-m Anglo-Australian Telescope (AAT). The primary aim of the survey is to precisely measure the scale of baryon acoustic oscillations (BAO) imprinted on the spatial distribution of these galaxies at look-back times of 4–8 Gyr. The target galaxies are selected using ultraviolet (UV) photometry from the Galaxy Evolution Explorer satellite, with a flux limit of . We also require that the targets are detected at optical wavelengths, specifically in the range . We use the Lyman break method applied to the UV colours, with additional optical colour limits, to select high-redshift galaxies. The galaxies generally have strong emission lines, permitting reliable redshift measurements in relatively short exposure times on the AAT. The median redshift of the galaxies is . The redshift range containing 90 per cent of the galaxies is . The survey will sample a volume of ∼1 Gpc3 over a projected area on the sky of 1000 deg2, with an average target density of 350 deg−2. Detailed forecasts indicate that the survey will measure the BAO scale to better than 2 per cent and the tangential and radial acoustic wave scales to approximately 3 and 5 per cent, respectively. Combining the WiggleZ constraints with existing cosmic microwave background measurements and the latest supernova data, the marginalized uncertainties in the cosmological model are expected to be and (for a constant w model). The WiggleZ measurement of w will constitute a robust, precise and independent test of dark energy models. This paper provides a detailed description of the survey and its design, as well as the spectroscopic observations, data reduction and redshift measurement techniques employed. It also presents an analysis of the properties of the target galaxies, including emission-line diagnostics which show that they are mostly extreme starburst galaxies, and Hubble Space Telescope images, which show that they contain a high fraction of interacting or distorted systems. In conjunction with this paper, we make a public data release of data for the first 100 000 galaxies measured for the project. [ABSTRACT FROM AUTHOR]
- Published
- 2010
- Full Text
- View/download PDF
44. The WiggleZ Dark Energy Survey: small-scale clustering of Lyman-break galaxies at z < 1.
- Author
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Blake, Chris, Jurek, Russell J., Brough, Sarah, Colless, Matthew, Couch, Warrick, Croom, Scott, Davis, Tamara, Drinkwater, Michael J., Forbes, Duncan, Glazebrook, Karl, Madore, Barry, Martin, Chris, Pimbblet, Kevin, Poole, Gregory B., Pracy, Michael, Sharp, Rob, Small, Todd, and Woods, David
- Subjects
- *
DARK energy , *REDSHIFT , *ULTRAVIOLET astronomy , *BARYONS , *COSMIC background radiation , *GALAXIES - Abstract
The WiggleZ Dark Energy Survey is a large-scale structure survey of intermediate-redshift ultraviolet-selected (UV-selected) emission-line galaxies scheduled to cover 1000 deg2, spanning a broad redshift range . The main scientific goal of the survey is the measurement of baryon acoustic oscillations (BAO) in the galaxy clustering pattern at a significantly higher redshift than previous studies. The BAO may be applied as a standard cosmological ruler to constrain dark energy models. Based on the first 20 per cent of the data set, we present initial results concerning the small-scale clustering of the WiggleZ targets, together with survey forecasts. The WiggleZ galaxy population possesses a clustering length Mpc, which is significantly larger than UV-selected samples, with a slope . This clustering length is comparable to Lyman-break galaxies with similar UV luminosities. The clustering strength of the sample increases with optical luminosity, UV luminosity and reddening rest-frame colour. The full survey, scheduled for completion in 2010, will map an effective volume Gpc3 (evaluated at a scale ) and will measure the angular diameter distance and Hubble expansion rates in three redshift bins with accuracies of ≈5 per cent. We will determine the value of a constant dark energy equation-of-state parameter, wcons, with a higher precision than existing supernovae observations using an entirely independent technique. The WiggleZ and supernova measurements lie in highly complementary directions in the plane of wcons and the matter density Ωm. The forecast using the full combination of WiggleZ, supernova and cosmic microwave background (CMB) data sets is a marginalized error , providing a robust and precise measurement of the properties of dark energy including cross-checking of systematic errors. [ABSTRACT FROM AUTHOR]
- Published
- 2009
- Full Text
- View/download PDF
45. Extragalactic integral field spectroscopy on the Gemini telescopes
- Author
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Bunker, Andrew, Smith, Joanna, Parry, Ian, Ben Metcalf, R., Sharp, Rob, de Grijs, Richard, Bower, Richard, and Swinbank, Mark
- Subjects
- *
TELESCOPES , *SPECTRUM analysis , *NEAR infrared spectroscopy , *GALAXIES , *STAR formation - Abstract
Abstract: We have undertaken a programme on the Gemini 8-m telescopes to demonstrate the power of integral field spectroscopy, using the CIRPASS instrument in the near-infrared. Here, we present some of our results from 3D spectroscopy of extra-galactic objects: mapping the Hα velocity field in a z ≈1 disc galaxy; exploring dark matter sub-structure through observations of an Einstein cross gravitational lens; and the star formation time-scales of young massive clusters in a starburst galaxy. [Copyright &y& Elsevier]
- Published
- 2006
- Full Text
- View/download PDF
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