Results for "L. F. Edge"

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Circuit Quantum Electrodynamics Architecture for Gate-Defined Quantum Dots in SiliconOct 18 2016We demonstrate a hybrid device architecture where the charge states in a double quantum dot (DQD) formed in a Si/SiGe heterostructure are read out using an on-chip superconducting microwave cavity. A quality factor Q = 5,400 is achieved by selectively ... More
Cold fronts and metal anisotropies in the X-ray cool core of the galaxy cluster Zw1742+3306May 16 2013May 29 2013(Context) In recent years, our understanding of the cool cores of galaxy clusters has changed. Once thought to be relatively simple places where gas cools and flows toward the centre, now they are believed to be very dynamic places where heating from ... More
Constraining Cosmological Topology via Highly Luminous X-ray ClustersJun 16 1997The topology of the observable Universe is not yet known. The most significant observational sign of a non-trivial topology would be multiple images (``ghosts'') of a single object at (in general) different sky positions and redshifts. It is pointed out ... More
A Giant Arc in a ROSAT Detected Cluster of GalaxiesJul 25 1994We report the serendipitous discovery of a giant grvitational arc in the Abell Supplementary cluster S295 during optical follow-up observations of clusters detected in the ROSAT All-Sky Survey. The cluster has a redshift z=0.3007 and a velocity dispersion ... More
A simluated TCDM cosmology cluster catalogue: the NFW profile and the temperature-mass scaling relationsJul 24 2000We have extracted over 400 clusters, covering more than 2 decades in mass, from three simulations of the TCDM cosmology. This represents the largest, uniform catalogue of simulated clusters ever produced. The clusters exhibit a wide variety of density-profiles. ... More
Site-selective quantum control in an isotopically enriched 28Si/SiGe quadruple quantum dotMar 14 2019Silicon spin qubits are a promising quantum computing platform offering long coherence times, small device sizes, and compatibility with industry-backed device fabrication techniques. In recent years, high fidelity single-qubit and two-qubit operations ... More
Discovery of a diffuse optical line emitting halo in the core of the Centaurus cluster of galaxies: Line emission outside the protection of the filamentsMar 26 2018Jan 16 2019We present the discovery of diffuse optical line emission in the Centaurus cluster seen with the MUSE IFU. The unparalleled sensitivity of MUSE allows us to detect the faint emission from these structures which extend well beyond the bounds of the previously ... More
The role of spin-orbit coupling in topologically protected interface states in Dirac materialsFeb 18 2014May 16 2014We highlight the fact that two-dimensional materials with Dirac-like low energy band structures and spin-orbit coupling will produce linearly dispersing topologically protected Jackiw-Rebbi modes at interfaces where the Dirac mass changes sign. These ... More
The binary period and outburst behaviour of the SMC X-ray binary pulsar system SXP504May 17 2005A probable binary period has been detected in the optical counterpart to the X-ray source CXOU J005455.6-724510 = RX J0054.9-7245 = AXJ0054.8-7244 = SXP504 in the Small Magellanic Cloud. This source was detected by Chandra on 04 Jul 2002 and subsequently ... More
Optical Emission Line Nebulae in Galaxy Cluster Cores 1: The Morphological, Kinematic and Spectral Properties of the SampleMar 09 2016We present an Integral Field Unit survey of 73 galaxy clusters and groups with the VIsible Multi Object Spectrograph (VIMOS) on VLT. We exploit the data to determine the H$\alpha$ gas dynamics on kpc-scales to study the feedback processes occurring within ... More
Si-compatible candidates for high-K dielectrics with the Pbnm perovskite structureMay 16 2010Aug 03 2010We analyze both experimentally (where possible) and theoretically from first-principles the dielectric tensor components and crystal structure of five classes of Pbnm perovskites. All of these materials are believed to be stable on silicon and are therefore ... More
A new measurement of the bulk flow of X-ray luminous clusters of galaxiesOct 26 2009Mar 11 2010We present new measurements of the large-scale bulk flows of galaxy clusters based on 5-year WMAP data and a significantly expanded X-ray cluster catalogue. Our method probes the flow via measurements of the kinematic Sunyaev-Zeldovich (SZ) effect produced ... More
The error budget of the Dark Flow measurementJan 08 2010Jun 14 2010We analyze the uncertainties and possible systematics associated with the "Dark Flow" measurements using the cumulative Sunyaev-Zeldovich effect combined with all-sky catalogs of clusters of galaxies. Filtering of all-sky cosmic microwave background (CMB) ... More
The effect of radiative cooling on the X-ray properties of galaxy clustersAug 06 1999Jun 02 2000In this paper, we investigate the effect of cooling on the X-ray properties of galaxy clusters. We have performed N-body, hydrodynamical simulations both with and without the effects of radiative cooling, but neglecting the effects of star formation and ... More
A very extended molecular web around NGC 1275May 16 2011We present the first detection of CO emission lines in the Halpha filaments at distances as far as 50 kpc from the centre of the galaxy NGC 1275. This gas is probably dense (>=10E3 cm-3). However, it is not possible to accurately determine the density ... More
Observations of CO in the eastern filaments of NGC 1275Apr 04 2008We recently found extended CO(2-1) emission from cold molecular gas embedded in the network of Halpha filaments surrounding the galaxy NGC 1275 (Salome et al. 2006). We now present CO(2-1) interferometer maps of the eastern filaments, at high spatial ... More
Optical properties of SMC X-ray binariesOct 04 2004This work represent the first major study of the optical and IR characteristics of the mass donor companions to the X-ray pulsars in the Small Magellanic Cloud (SMC). In this work several new counterparts have been identified, and possible ones confirmed, ... More
A Stacked Analysis of Brightest Cluster Galaxies Observed with the Fermi Large Area TelescopeNov 27 2012We present the results of a search for high-energy gamma-ray emission from a large sample of galaxy clusters sharing the properties of three existing Fermi-LAT detections (in Perseus, Virgo and Abell 3392), namely a powerful radio source within their ... More
The effect of radiative cooling on X-ray emission from clusters of galaxiesDec 01 1999In this paper we use state-of-the-art N-body hydrodynamic simulations of a cosmological volume of side 100Mpc to produce many galaxy clusters simultaneously in both the standard cold dark matter (SCDM) cosmology and a cosmology with a positive cosmological ... More
X-Ray and Optical Observations of XTE J0052-723 a Transient Be/X-Ray Pulsar in the Small Magellanic CloudOct 17 2002On December 27th 2000 during our regular SMC monitoring program with Rossi X-ray Timing Explorer, strong pulsations were detected with a period of 4.78 seconds. Subsequent slew observations performed on Jan 9th and 13th across the field of view allowed ... More
A major outburst from the X-ray binary RX J0520.5-6932Jan 26 2004We report on the analysis of 8 years of MAssive Compact Halo Objects (MACHO) data for the source RX J0520.5-6932. A regular period of 24.4 days has been confirmed, however this is manifest almost entirely in the red part of the spectrum. A major outburst, ... More
A complete sample of twelve very X-ray luminous galaxy clusters at z>0.5Mar 15 2007We present the statistically complete and cosmologically most relevant subset of the twelve most distant galaxy clusters detected at z>0.5 by the MAssive Cluster Survey (MACS). Ten of these systems are new discoveries; only two (MACSJ0018.5+1626 aka CL0016+1609, ... More
The evolution of the red sequence slope in massive galaxy clustersJan 09 2009We investigate the evolution of the optical and near-infrared colour-magnitude relation in an homogeneous sample of massive clusters from z = 1 to the present epoch. By comparing deep Hubble Space Telescope ACS imaging of X-ray selected MACS survey clusters ... More
ESO-Athena Synergy White PaperMay 17 2017The Advanced Telescope for High ENergy Astrophysics (Athena) is the X-ray observatory mission selected by ESA within its Cosmic Vision 2015-2025 programme to address the Hot and Energetic Universe scientific theme. The ESO-Athena Synergy Team (EAST) has ... More
Cold gas dynamics in Hydra-A: evidence for a rotating diskOct 16 2013We present multi-frequency observations of the radio galaxy Hydra-A (3C218) located in the core of a massive, X-ray luminous galaxy cluster. IFU spectroscopy is used to trace the kinematics of the ionised and warm molecular hydrogen which are consistent ... More
Spin-Blockade Spectroscopy of Si/SiGe Quantum DotsSep 21 2018We implement a technique for measuring the singlet-triplet energy splitting responsible for spin-to-charge conversion in semiconductor quantum dots. This method, which requires fast, single-shot charge measurement, reliably extracts an energy in the limits ... More
Discovery of radio halos and double-relics in distant MACS galaxy clusters: clues to the efficiency of particle accelerationJun 26 2012We have performed 323 MHz observations with the Giant Metrewave Radio Telescope of the most promising candidates selected from the MACS catalog. The aim of the work is to extend our knowledge of the radio halo and relic populations to z>0.3, the epoch ... More
An ALMA Survey of Submillimeter Galaxies in the Extended Chandra Deep Field South: Near-infrared morphologies and stellar sizesDec 01 2014We analyse HST WFC3/$H_{160}$-band observations of a sample of 48 ALMA-detected submillimeter galaxies (SMGs) in the Extended Chandra Deep Field South field, to study their stellar morphologies and sizes. We detect 79$\pm$17% of the SMGs in the $H_{160}$-band ... More
Cold gas in the Perseus cluster core: Excitation of molecular gas in filamentsApr 14 2008We have recently detected CO lines in the well-known filaments around NGC 1275, the galaxy at the centre of the Perseus cluster of galaxies. These previous observations, with the HERA multi-beam array at the IRAM 30m telescope enabled us to make a large ... More
X-ray Surveys of Low-redshift ClustersJul 08 2003The selection of clusters of galaxies through their X-ray emission has proved to be an extremely powerful technique over the past four decades. The growth of X-ray astronomy has provided the community with a steadily more detailed view of the intracluster ... More
Classification of spin models for Yang-Baxter planar algebrasFeb 24 2019In this paper, we classify all spin models for singly-generated Yang-Baxter planar algebras in terms of certain highly regular graphs. Using Liu's classification of singly generated Yang-Baxter planar algebras, this classifies all spin models for the ... More
Metal--topological-insulator transition in the quantum kicked rotator with Z2 symmetryJan 16 2012Apr 25 2012The quantum kicked rotator is a periodically driven dynamical system with a metal-insulator transition. We extend the model so that it includes phase transitions between a metal and a topological insulator, in the universality class of the quantum spin ... More
Non-thermal emission and dynamical state of massive galaxy clusters from CLASH sampleDec 01 2016Massive galaxy clusters are the most violent large scale structures undergoing merger events in the Universe. Based upon their morphological properties in X-rays, they are classified as un-relaxed and relaxed clusters and often host (a fraction of them) ... More
The detection of molecular gas in the central galaxies of cooling-flow clustersJun 13 2001We present the detections of CO line emission in the central galaxy of sixteen extreme cooling flow clusters using the IRAM 30m and the JCMT 15m. These detections of CO(1-0), CO(2-1), CO(3-2) and CO(4-3) are consistent with the presence of a substantial ... More
Quantifying the suppression of the (un)-obscured star formation in galaxy cluster cores at 0.2$\lesssim$$z$$\lesssim$0.9Dec 20 2018We quantify the star formation (SF) in the inner cores ($\mathcal{R}$/$R_{200}$$\leq$0.3) of 24 massive galaxy clusters at 0.2$\lesssim$$z$$\lesssim$0.9 observed by the $Herschel$ Lensing Survey and the Cluster Lensing and Supernova survey with $Hubble$. ... More
Shaken Snow Globes: Kinematic Tracers of the Multiphase Condensation Cascade in Massive Galaxies, Groups, and ClustersSep 19 2017Feb 09 2018We propose a novel method to constrain turbulence and bulk motions in massive galaxies, groups and clusters, exploring both simulations and observations. As emerged in the recent picture of the top-down multiphase condensation, the hot gaseous halos are ... More
Multiphase Signatures of AGN Feedback in Abell 2597May 10 2012We present new Chandra X-ray observations of the brightest cluster galaxy (BCG) in the cool core cluster Abell 2597. The data reveal an extensive kpc-scale X-ray cavity network as well as a 15 kpc filament of soft-excess gas exhibiting strong spatial ... More
Radio spectra and sizes of ALMA-identified submillimetre galaxies: evidence of age-related spectral curvature and cosmic ray diffusion?Apr 18 2019We analyse the multi-frequency radio spectral properties of $41$ 6GHz-detected ALMA-identified, submillimetre galaxies (SMGs), observed at 610MHz, 1.4GHz, 6GHz with GMRT and the VLA. Combining high-resolution ($\sim0.5''$) 6GHz radio and ALMA $870\,\mu$m ... More
A Non-thermal Study of the Brightest Cluster Galaxy NGC 1275 - The Gamma-Radio Connection Over Four DecadesMay 14 2014Emission from the active nucleus in the core of the brightest cluster galaxy of the Perseus cluster, NGC 1275, has varied dramatically over the past four decades. Prompted by the Fermi detection of flaring in the gamma-ray band, we present the recent ... More
The X-ray brightest clusters of galaxies from the Massive Cluster SurveyApr 27 2010We present a statistically complete sample of very X-ray luminous galaxy clusters detected in the MAssive Cluster Survey (MACS). This second MACS release comprises all 34 MACS clusters with nominal X-ray fluxes in excess of 2x10^(-12) erg/s/cm^2 (0.1-2.4 ... More
Residual Cooling and Persistent Star Formation amid AGN Feedback in Abell 2597May 10 2012New Chandra X-ray and Herschel FIR observations enable a multiwavelength study of active galactic nucleus (AGN) heating and intracluster medium (ICM) cooling in the brightest cluster galaxy of Abell 2597. The new Chandra observations reveal the central ... More
An ALMA survey of submillimeter galaxies in the Extended Chandra Deep Field South: Source catalog and multiplicityApr 15 2013We present an Atacama Large Millimeter/submillimeter Array (ALMA) Cycle 0 survey of 126 submillimeter sources from the LABOCA ECDFS Submillimeter Survey (LESS). Our 870 micron survey with ALMA (ALESS) has produced maps ~3X deeper and with a beam area ... More
Revealing the velocity structure of the filamentary nebula in NGC 1275 in its entiretyJan 31 2018We have produced for the first time a detailed velocity map of the giant filamentary nebula surrounding NGC 1275, the Perseus cluster's brightest galaxy, and revealed a previously unknown rich velocity structure across the entire nebula. We present new ... More
Revealing the velocity structure of the filamentary nebula in NGC 1275 in its entiretyJan 31 2018Feb 08 2018We have produced for the first time a detailed velocity map of the giant filamentary nebula surrounding NGC 1275, the Perseus cluster's brightest galaxy, and revealed a previously unknown rich velocity structure across the entire nebula. We present new ... More
The dust and [CII] morphologies of redshift ~4.5 sub-millimeter galaxies at ~200pc resolution: The absence of large clumps in the interstellar medium of high-redshift galaxiesApr 10 2018We present deep high resolution (0.03", 200pc) ALMA Band 7 observations covering the dust continuum and [CII] $\lambda157.7\mu$m emission in four $z\sim4.4-4.8$ sub-millimeter galaxies (SMGs) selected from the ALESS and AS2UDS surveys. The data show that ... More
[CII] and 12CO(1-0) Emission Maps in HLSJ091828.6+514223: A Strongly Lensed Interacting System at z=5.24Oct 15 2013Jan 15 2014We present Submillimeter Array (SMA) [CII] 158um and Jansky Very Large Array (JVLA) $^{12}$CO(1-0) line emission maps for the bright, lensed, submillimeter source at $z=5.2430$ behind Abell 773: HLSJ091828.6+514223 (HLS0918). We combine these measurements ... More
Herschel photometry of brightest cluster galaxies in cooling flow clustersMay 07 2010May 10 2010The dust destruction timescales in the cores of clusters of galaxies are relatively short given their high central gas densities. However, substantial mid-infrared and sub-mm emission has been detected in many brightest cluster galaxies. In this letter ... More
Herschel observations of FIR emission lines in brightest cluster galaxiesMay 07 2010May 10 2010The question of how much gas cools in the cores of clusters of galaxies has been the focus of many, multiwavelength studies in the past 30 years. In this letter we present the first detections of the strongest atomic cooling lines, [C II], [O I] and [N ... More
Kiloparsec-scale dust disks in high-redshift luminous submillimeter galaxiesSep 30 2016We present high-resolution (0.16$"$) 870um Atacama Large Millimeter/submillimeter Array (ALMA) imaging of 16 luminous (L_IR ~ 4 x 10^12 L_sun) submillimeter galaxies (SMGs) from the ALESS survey of the Extended Chandra Deep Field South. This dust imaging ... More
A spectacular giant arc in the massive cluster lens MACSJ1206.2-0847Jan 14 2009We discuss the X-ray and optical properties of the massive galaxy cluster MACSJ1206.2-0847 (z=0.4385), discovered in the Massive Cluster Survey (MACS). Our Chandra observation of the system yields a total X-ray luminosity of 2.4 x 10^45 erg/s (0.1-2.4 ... More
Cold molecular gas in the Perseus cluster core - Association with X-ray cavity, Halpha filaments and cooling flow -Mar 14 2006Cold molecular gas has been recently detected in several cooling flow clusters of galaxies where huge optical nebulosities often stand. These optical filaments are tightly linked to the cooling flow and to the related phenomena, like the rising bubbles ... More
Storm in a "Teacup": a radio-quiet quasar with ~10kpc radio-emitting bubbles and extreme gas kinematicsOct 15 2014Jan 30 2015We present multi-frequency (1-8 GHz) VLA data, combined with VIMOS IFU data and HST imaging, of a z=0.085 radio-quiet type 2 quasar (with L(1.4GHz)~5e23 W/Hz and L(AGN)~2e45 erg/s). Due to the morphology of its emission-line region, the target (J1430+1339) ... More
An enormous molecular gas flow in the RXJ0821+0752 galaxy clusterNov 23 2018We present recent {\it Chandra} X-ray observations of the RXJ0821.0+0752 galaxy cluster in addition to ALMA observations of the CO(1-0) and CO(3-2) line emission tracing the molecular gas in its central galaxy. All of the CO line emission, originating ... More
A $^{13}$CO Detection in a Brightest Cluster GalaxySep 27 2017We present ALMA Cycle 4 observations of CO(1-0), CO(3-2), and $^{13}$CO(3-2) line emission in the brightest cluster galaxy of RXJ0821+0752. This is one of the first detections of $^{13}$CO line emission in a galaxy cluster. Half of the CO(3-2) line emission ... More
Mass Distribution in Galaxy Cluster CoresOct 14 2016Many processes within galaxy clusters, such as those believed to govern the onset of thermally unstable cooling and AGN feedback, are dependent upon local dynamical timescales. However, accurately mapping the mass distribution within individual clusters ... More
Molecular gas filaments and star-forming knots beneath an X-ray cavity in RXC J1504-0248Jul 11 2018We present recent ALMA observations of the CO(1-0) and CO(3-2) emission lines in the brightest cluster galaxy of RXCJ1504.1$-$0248, which is one of the most extreme cool core clusters known. The central galaxy contains $1.9\times 10^{10}~M_{\odot}$ of ... More
X-ray variability in a deep, flux limited sample of QSOsDec 03 1999Apr 07 2000We present an analysis of X-ray variability in a flux limited sample of QSOs. Selected from our deep ROSAT survey, these QSOs span a wide range in redshift ($0.1<z<3.2$) and are typically very faint, so we have developed a method to constrain the amplitude ... More
Angular correlation function of 1.5 million LRGs: clustering evolution and a search for BAODec 02 2009Jul 06 2011We present the angular correlation function measured from photometric samples comprising 1,562,800 luminous red galaxies (LRGs). Three LRG samples were extracted from the Sloan Digital Sky Survey (SDSS) imaging data, based on colour-cut selections at ... More
A Mechanism for Stimulating AGN Feedback by Lifting Gas in Massive GalaxiesApr 15 2016Aug 17 2016Observation shows that nebular emission, molecular gas, and young stars in giant galaxies are associated with rising X-ray bubbles inflated by radio jets launched from nuclear black holes. We propose a model where molecular clouds condense from low entropy ... More
Driving massive molecular gas flows in central cluster galaxies with AGN feedbackFeb 25 2019We present an analysis of new and archival ALMA observations of molecular gas in twelve central cluster galaxies. We examine emerging trends in molecular filament morphology and their velocities to understand their origins. Molecular gas masses in cluster ... More
Cataclysmic variables from a ROSAT/2MASS selection I: Four new intermediate polarsApr 21 2005We report the first results from a new search for cataclysmic variables (CVs) using a combined X-ray (ROSAT) / infrared (2MASS) target selection that discriminates against background AGN. Identification spectra were obtained at the Isaac Newton Telescope ... More
Study of the cyclotron feature in MXB 0656-072Feb 06 2006We have monitored a Type II outburst of the Be/X-ray binary MXB 0656-072 in a series of pointed RXTE observations during October through December 2003. The source spectrum shows a cyclotron resonance scattering feature at 32.8 +/- 0.5 keV, corresponding ... More
13CO and C18O emission from a dense gas disk at z=2.3: abundance variations, cosmic rays and the initial conditions for star formationSep 23 2013We analyse the SLEDs of 13CO and C18O for the J=1-0 up to J=7-6 transitions in the gravitationally lensed ultraluminous infrared galaxy SMMJ2135-0102 at z=2.3. This is the first detection of 13CO and C18O in a high-redshift star-forming galaxy. These ... More
Three new X-ray pulsars detected in the Small Magellanic Cloud and the positions of two other known pulsars determinedJun 25 2004Jun 28 2004Three new X-ray pulsars have been detected in the Small Magellanic Cloud (SMC) and the positions of two others have been determined, with archive Chandra data. A series of five observations of the SMC took place between May and October 2002. Analysis ... More
Chandra X-ray observations of the hyper-luminous infrared galaxy IRAS F15307+3252Jun 24 2016Sep 23 2016Hyper-luminous infrared galaxies (HyLIRGs) lie at the extreme luminosity end of the IR galaxy population with $L_{\rm IR}>10^{13}$L$_\odot$. They are thought to be closer counterparts of the more distant sub-mm galaxies, and should therefore be optimal ... More
Large-scale Structure and Dynamics of the Most X-ray Luminous Galaxy Cluster Known -- RX J1347-1145Dec 11 2009We present photometric, spectroscopic and weak lensing analysis of the large-scale structure and dynamics of the most X-ray luminous galaxy cluster known, RX J1347-1145, at z=0.451. We spectroscopically confirmed 47 new members with LDSS3 on the Magellan ... More
X-ray selected galaxy clusters in the Pan-STARRS Medium-Deep SurveyMar 03 2013Apr 28 2013[abridged] We present the results of a pilot study for the extended MACS survey (eMACS), a comprehensive search for distant, X-ray luminous galaxy clusters at z>0.5. Our pilot study applies the eMACS concept to the 71 deg^2 area extended by the ten fields ... More
The Relation Between Line Emission and Brightest Cluster Galaxies in Three Exceptional Clusters: Evidence for Gas Cooling from the ICMDec 20 2011There is a strong spatial correlation between brightest cluster galaxies (BCGs) and the peak density and cooling rate of the intra-cluster medium (ICM). In this paper we combine integral field spectroscopy, CO observations and X-ray data to study three ... More
The REFLEX galaxy cluster survey. VIII. Spectroscopic observations and optical atlasJul 31 2009We present the final data from the spectroscopic survey of the ROSAT-ESO Flux-Limited X-ray (REFLEX) catalog of galaxy clusters. The REFLEX survey covers 4.24 steradians (34% of the entire sky) below a declination of 2.5 deg and at high Galactic latitude ... More
Mystery solved: discovery of extended radio emission in the merging galaxy cluster Abell 2146Aug 11 2017Dec 01 2017Abell 2146 ($z=0.232$) is a massive galaxy cluster currently undergoing a spectacular merger in the plane of the sky with a bullet-like morphology. It was the first system in which both the bow and upstream shock fronts were detected at X-ray wavelengths ... More
Edge-state enhanced transport in a 2-dimensional quantum walkNov 14 2014Dec 04 2014Quantum walks on translation invariant regular graphs spread quadratically faster than their classical counterparts. The same coherence that gives them this quantum speedup inhibits, or even stops their spread in the presence of disorder. We ask how to ... More
Jet Launching Radius in Low-Power Radio-Loud AGNs in Advection-Dominated Accretion FlowsMar 10 2018May 09 2018Using our theory for the production of relativistic outflows, we estimate the jet launching radius and the inferred mass accretion rate for 52 low-power radio-loud AGNs based on the observed jet powers. Our analysis indicates that (1) a significant fraction ... More
Optical counterparts to four X-ray sources in the Small Magellanic CloudSep 17 2002Sep 19 2002We report on the spectroscopic and photometric analysis of possible optical counterparts to four X-ray sources in the Small Magellanic Cloud: AX J0049.4-7323, AX J0057.4-7325, RX J0058.2-7321 and RX J0101.1-7206. In the case of the last two, we suggest ... More
Localisation, delocalisation, and topological transitions in disordered 2D quantum walksNov 27 2014Mar 16 2015We investigate time-independent disorder on several two-dimensional discrete-time quantum walks. We find numerically that, contrary to claims in the literature, random onsite phase disorder, spin-dependent or otherwise, cannot localise the Hadamard quantum ... More
On the Reliability of RAID Systems: An Argument for More Check DrivesFeb 16 2012In this paper we address issues of reliability of RAID systems. We focus on "big data" systems with a large number of drives and advanced error correction schemes beyond \RAID{6}. Our RAID paradigm is based on Reed-Solomon codes, and thus we assume that ... More
Probing ultracold Fermi gases with light-induced gauge potentialsFeb 07 2011May 25 2011We theoretically investigate the response of a two component Fermi gas to vector potentials which couple separately to the two spin components. Such vector potentials may be implemented in ultracold atomic gases using optically dressed states. Our study ... More
MACS: The evolution and properties of massive clusters of galaxiesJan 18 2000We present first results from the MAssive Cluster Survey (MACS), a new large-scale X-ray survey designed to find and characterize very massive, distant clusters of galaxies. Based on X-ray detections in the ROSAT All-Sky Survey, MACS aims to compile a ... More
AX J0049.4-7323 - a close look at a neutron star interacting with a circumstellar diskFeb 02 2004Detailed evidence on the system AX J0049.4-7323 is presented here to show how the passage of the neutron star in the binary system disrupts the circumstellar disk of the mass donor Be star. A similar effect is noted in three other Be/X-ray binary systems. ... More
Upper critical field as a probe for multiband superconductivity in bulk and interfacial STOJan 21 2014Oct 16 2014We investigate the temperature dependence of the upper critical field $H_{c 2} $ as a tool to probe the possible presence of multiband superconductivity at the interface of LAO/STO. The behaviour of $H_{c 2} $ can clearly indicate two-band superconductivity ... More
Robot Communication Via Motion: Closing the Underwater Human-Robot Interaction LoopSep 21 2018In this paper, we propose a novel method for underwater robot-to-human communication using the motion of the robot as "body language". To evaluate this system, we develop simulated examples of the system's body language gestures, called kinemes, and compare ... More
Collective modes as a probe of imbalanced Fermi gasesDec 29 2009Jun 18 2010We theoretically investigate the collective modes of imbalanced two component one-dimensional Fermi gases with attractive interactions. This is done for trapped and untrapped systems both at zero and non-zero temperature, using self-consistent mean-field ... More
Signature of the FFLO phase in the collective modes of a trapped ultracold Fermi gasJun 09 2009Aug 07 2009We study theoretically the collective modes of a two-component Fermi gas with attractive interactions in a quasi-one-dimensional harmonic trap. We focus on an imbalanced gas in the Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) phase. Using a mean-field theory, ... More
A Chandra Study of the Complex Structure in the Core of 2A 0335+096Mar 13 2003We present a Chandra observation of the central (r< 200kpc) region of the cluster of galaxies 2A 0335+096, rich in interesting phenomena. On large scales (r> 40kpc), the X-ray surface brightness is symmetric and slightly elliptical. The cluster has a ... More
H0 from an orientation-unbiased sample of SZ and X-ray clustersMar 02 2001We have observed the Sunyaev-Zel'dovich effect in a sample of five moderate-redshift clusters with the Ryle Telescope, and used them in conjunction with X-ray imaging and spectral data from ROSAT and ASCA to measure the Hubble constant. This sample was ... More
Close entrainment of massive molecular gas flows by radio bubbles in the central galaxy of Abell 1795Aug 29 2017We present new ALMA observations tracing the morphology and velocity structure of the molecular gas in the central galaxy of the cluster Abell 1795. The molecular gas lies in two filaments that extend 5 - 7 kpc to the N and S from the nucleus and project ... More
The UKIRT Infrared Deep Sky Survey Early Data ReleaseMar 22 2006Sep 01 2006This paper defines the UKIRT Infrared Deep Sky Survey (UKIDSS) Early Data Release (EDR). UKIDSS is a set of five large near-infra-red surveys defined by Lawrence et al. (2006), being undertaken with the UK Infra-red Telescope (UKIRT) Wide Field Camera ... More
A measurement of H_0 from Ryle Telescope, ASCA and ROSAT observations of Abell 773Apr 13 1999Mar 10 2003We present new Ryle Telescope (RT) observations of the Sunyaev Zel'dovich (SZ) decrement from the cluster Abell 773. The field contains a number of faint radio sources that required careful subtraction. We use ASCA observations to measure the gas temperature ... More
The Chandra Small Magellanic Cloud Wing Survey - the search for X-ray BinariesOct 11 2007We have detected 523 sources in a survey of the Small Magellanic Cloud (SMC) Wing with Chandra. By cross-correlating the X-ray data with optical and near-infrared catalogues we have found 300 matches. Using a technique that combines X-ray colours and ... More
The ROSAT-ESO Flux Limited X-Ray (REFLEX) Galaxy Cluster Survey I: The Construction of the Cluster SampleDec 12 2000We describe the construction of an X-ray flux-limited sample of galaxy clusters, the REFLEX survey catalogue, to be used for cosmological studies. The survey is based on the ROSAT All-Sky Survey and on extensive follow-up observations conducted in the ... More
An Infrared Survey of Brightest Cluster Galaxies. II: Why are Some Brightest Cluster Galaxies Forming Stars?Mar 12 2008Quillen et al.(2007) presented an imaging survey with the {\it Spitzer Space Telescope} of 62 brightest cluster galaxies with optical line emission located in the cores of X-ray luminous clusters. They found that at least half of these sources have signs ... More
X-ray bright sources in the Chandra Small Magellanic Cloud Wing Survey - detection of two new pulsarsJan 08 2007We investigate the X-ray and optical properties of a sample of X-ray bright sources from the Small Magellanic Cloud (SMC) Wing Survey. We have detected two new pulsars with pulse periods of 65.8 s (CXOU J010712.6-723533) and 700 s (CXOU J010206.6-714115), ... More
The REFLEX Cluster Survey: Observing Strategy and First Results on Large-Scale StructureMar 25 1999We give a general description of the optical observing strategy of the ROSAT-ESO Flux-Limited X-ray (REFLEX) cluster survey. This presently includes 460 clusters of galaxies selected from the ROSAT All-Sky Survey in the Southern hemisphere, to a flux ... More
The ROSAT-ESO Flux Limited X-ray (REFLEX) Galaxy Cluster Survey. V. The cluster catalogueMay 27 2004We present the catalogue of the REFLEX Cluster Survey providing information on the X-ray properties, redshifts, and some identification details of the clusters in the REFLEX sample. The catalogue describes a statistically complete X-ray flux-limited sample ... More
An infrared survey of brightest cluster galaxies: Paper INov 07 2007We report on an imaging survey with the Spitzer Space Telescope of 62 brightest cluster galaxies with optical line emission. These galaxies are located in the cores of X-ray luminous clusters selected from the ROSAT All-Sky Survey. We find that about ... More
The REFLEX Galaxy Cluster Survey IV: The X-ray Luminosity FunctionJun 13 2001The X-ray galaxy cluster sample from the REFLEX Cluster Survey, which covers the X-ray brightest galaxy clusters detected in the ROSAT All-Sky Survey in the southern sky, is used to construct the X-ray luminosity function of clusters in the local Universe. ... More
Shock fronts, electron-ion equilibration and ICM transport processes in the merging cluster Abell 2146Feb 23 2012We present a new 400 ks Chandra X-ray observation of the merging galaxy cluster Abell 2146. This deep observation reveals detailed structure associated with the major merger event including the Mach M=2.3+/-0.2 bow shock ahead of the dense, ram pressure ... More
Probing the Cosmic Large-Scale Structure with the REFLEX Cluster Survey : Profile of an ESO Key ProgrammeSep 29 1998Oct 01 1998The paper describes the goals and first results of the ROSAT ESO Flux-Limited X-ray (REFLEX) Cluster Survey, a redshift survey of the X-ray brightest galaxy clusters in the ROSAT All-Sky Survey in the southern hemisphere conducted in the frame of an ESO ... More
Resolved spectroscopy of gravitationally lensed galaxies: global dynamics and star-forming clumps on ~100pc scalesMar 26 2015We present adaptive optics-assisted integral field spectroscopy around the Ha or Hb lines of 12 gravitationally lensed galaxies obtained with VLT/SINFONI, Keck/OSIRIS and Gemini/NIFS. We combine these data with previous observations and investigate the ... More
The core of the massive cluster merger MACS J0417.5-1154 as seen by VLT/MUSEOct 31 2018Dec 06 2018We present a multi-wavelength analysis of the core of the massive galaxy cluster MACS\,J0417.5-1154 ($z = 0.441$; MACS\;J0417). Our analysis takes advantage of VLT/MUSE observations which allow the spectroscopic confirmation of three strongly-lensed systems. ... More
A Comprehensive Study of the Radio Properties of Brightest Cluster GalaxiesJul 10 2015We examine the radio properties of the Brightest Cluster Galaxies (BCGs) in a large sample of X-ray selected galaxy clusters comprising the Brightest Cluster Sample (BCS), the extended BCS (eBCS) and ROSAT-ESO Flux Limited X-ray (REFLEX) cluster catalogues. ... More