A5079224064- Galaxies: Formation, Evolution, Phenomena
- Astronomy and Astrophysical Research
- Stellar, planetary, and galactic studies
- Gamma-ray bursts and supernovae
- Astronomical Observations and Instrumentation
- Astrophysical Phenomena and Observations
- Adaptive optics and wavefront sensing
- Cosmology and Gravitation Theories
- Astrophysics and Cosmic Phenomena
- Radio Astronomy Observations and Technology
- Scientific Research and Discoveries
- Astrophysics and Star Formation Studies
- Geophysics and Gravity Measurements
- History and Developments in Astronomy
- Solar and Space Plasma Dynamics
- Statistical and numerical algorithms
- Dark Matter and Cosmic Phenomena
- Remote Sensing in Agriculture
- CCD and CMOS Imaging Sensors
- Calibration and Measurement Techniques
- Advanced Statistical Methods and Models
- Plant Water Relations and Carbon Dynamics
- Impact of Light on Environment and Health
- Distributed and Parallel Computing Systems
- Spectroscopy and Laser Applications
Durham University
2015-2024
Durham Technical Community College
1996-2007
University of Leicester
2000-2004
Australian Astronomical Observatory
2000-2001
Institute of Astronomy
1998
University of Southampton
1991
New College Durham
1983
We present the final catalogue of 2dF QSO Redshift Survey (2QZ), based on Anglo-Australian Telescope spectroscopic observations 44576 colour-selected (u b_J r) objects with 18.25<b_J<20.85 selected from APM scans UK Schmidt (UKST) photographic plates. The 2QZ comprises 23338 QSOs, 12292 galactic stars (including 2071 white dwarfs) and 4558 compact narrow-emission-line galaxies. obtained a reliable identification for 86 per cent observed 2dF. also report 6dF (6QZ), UKST 1564 brighter...
We present a determination of the optical QSO luminosity function and its cosmological evolution with redshift for sample over 6000 QSOs identified primarily from first observations 2dF Redshift Survey (2QZ). For -26 < M_B -23 0.35 z 2.3, we find that pure (PLE) models provide an acceptable fit to observed dependence function. The is best by two-power-law form. Exponential models, both as look-back time, general second-order polynomial redshift, were found fits dataset comprising 2QZ Large...
The SAMI Galaxy Survey will observe 3400 galaxies with the Sydney-AAO Multi-object Integral-field spectrograph (SAMI) on Anglo-Australian Telescope (AAT) in a 3-year survey which began 2013. We present throughput of system, science basis and specifications for target selection, observation plan combined properties selected galaxies. includes four volume limited galaxy samples based cuts proxy stellar mass, along low-stellar mass dwarf all from And Mass Assembly (GAMA) survey. GAMA regions...
In this paper we present a clustering analysis of quasi-stellar objects (QSOs) using over 20000 from the final catalogue 2dF QSO Redshift Survey (2QZ), measuring redshift-space two-point correlation function, ξ(s). When averaged redshift range 0.3 < z 2.2 find that ξ(s) is flat on small scales, steepening scales above ∼25h−1 Mpc. WMAP/2dF cosmology (Ωm = 0.27, ΩΛ 0.73) best-fitting power law with s0 5.48+0.42−0.48h−1 Mpc and γ= 1.20 ± 0.10 s 1 to 25h−1 We demonstrate non-linear distortions...
The VLT Survey Telescope (VST) ATLAS is an optical ugriz survey aiming to cover ~4700deg^2 of the Southern sky similar depths as Sloan Digital Sky (SDSS). From reduced images and object catalogues provided by Cambridge Astronomical Surveys Unit we first find that median seeing ranges from 0.8 arcsec FWHM in i 1.0 u, significantly better than 1.2-1.5 for SDSS. 5 sigma magnitude limit stellar sources r_AB=22.7 all bands these limits are at least faint SDSS more equivalent galaxy photometry...
We present a new determination of the QSO luminosity function and its evolution based primarily on large, complete catalogue 420 faint (B<20.9 mag) ultraviolet excess selected QSOs, for which spectroscopic identification redshifts have been obtained using fibreoptic system at Anglo–Australian Telescope. confirm that, magnitudes (B>20 mag), number–magnitude relation QSOs exhibits departure from steep power-law slope seen brighter (B<19.5 magnitudes, with surface density B<20.9 mag being equal...
This article summarizes principal findings from a conference convened by the American Cancer Society in June 1998 to examine health risks of cigar smoking. State-of-the-science reports were presented and 120 attendees (representing government private agencies, academia, educators, tobacco control experts) participated panels summary development discussions. The following conclusions reached consensus: (1) rates smoking are rising among both adults adolescents; (2) cigars instead cigarettes...
We present the QSO luminosity function of completed 2dF-SDSS LRG and (2SLAQ) survey, based on QSOs photometrically selected from Sloan Digital Sky Survey imaging data then observed spectroscopically using 2dF instrument Anglo-Australian Telescope. analyse 10637 in redshift range 0.4<z<2.6 to a g-band flux limit 21.85 (extinction corrected) an absolute continuum magnitude Mg(z=2)<-21.5. This sample covers area 191.9 deg^2. The binned agrees with that brighter SDSS main sample, but extends...
We combine the quasi-stellar object (QSO) samples from 2dF QSO Redshift Survey (2QZ) and 2dF-Sloan Digital Sky luminous red galaxy (LRG) (2dF-SDSS LRG QSO, hereafter 2SLAQ) in order to investigate clustering of z∼ 1.5 QSOs measure correlation function (ξ). The signal redshift-space projected along sky direction is similar that previously obtained 2QZ sample alone. By fitting functional forms for ξ(σ, π), measured across line sight, we find, as expected, β, dynamical infall parameter Ω0m,...
We present a catalogue comprising over 10 000 QSOs covering an effective area of 289.6 deg2, based on spectroscopic observations with the 2-degree Field (2dF) instrument at Anglo-Australian Telescope. This forms first release 2dF QSO Redshift Survey. candidates 18.25<bJ<20.85 were obtained from single homogeneous colour-selected APM measurements UK Schmidt photographic material. The final will contain approximately 25 and be released to public end 2002, one year after observational phase is...
We present a clustering analysis of Luminous Red Galaxies (LRGs) using nearly 9 000 objects from the final catalogue 2dF-SDSS LRG And QSO (2SLAQ) Survey. measure redshift-space two-point correlation function, xi(s), at mean redshift z=0.55. A single power-law fits deprojected xi(r), with length r_0=7.45+-0.35 Mpc and slope gamma=1.72+-0.06 in 0.4
Presentation des premiers resultats d'une etude spectroscopique d'environ 200 galaxies mesurees en utilisant le coupleur a fibre optique FOCAP du telescope anglo-australien. La strategie de l'etude et les techniques d'observation reduction donnees sont discutees. distribution redshift observee est comparee avec predictions d'un modele. Les spectres faibles compares ceux obtenus dans une brillantes. Une activite formation stellaire decouverte quelques-unes etudiees; implications discutees un...
We have used the 2dF instrument on AAT to obtain redshifts of a sample z<3, 18.0<g<21.85 quasars selected from SDSS imaging. These data are part larger joint programme: 2dF-SDSS LRG and QSO Survey (2SLAQ). describe quasar selection algorithm present resulting luminosity function 5645 in 105.7 deg^2. The bright end number counts agree well with determinations Redshift (2QZ) g\sim20.2. However, at faint 2SLAQ steeper than final 2QZ results Croom et al. (2004), but consistent preliminary Boyle...
We present a spectroscopic survey of almost 15 000 candidate intermediate-redshift luminous red galaxies (LRGs) brighter than i= 19.8, observed with 2dF on the Anglo-Australian Telescope. The targets were selected photometrically from Sloan Digital Sky Survey (SDSS) and lie along two narrow equatorial strips covering 180 deg2. Reliable redshifts obtained for 92 per cent selection is very efficient: over 90 have 0.45 < z 0.8. More 80 ∼11 pure absorption-line spectra consistent passively...
We report the serendipitous detection of a 0.2 L$^*$, Lyman-$\alpha$ emitting galaxy at redshift 2.5 an impact parameter 50 kpc from bright background QSO sightline. A high-resolution spectrum reveals partial Lyman-limit absorption system ($N_\mathrm{HI}=10^{16.94\pm0.10}$ cm$^{-2}$) with many associated metal lines same as foreground galaxy. Using photoionization models that carefully treat measurement errors and marginalise over uncertainties in shape normalisation ionizing radiation...
Strong-gravitational lens systems with quadruply-imaged quasars (quads) are unique probes to address several fundamental problems in cosmology and astrophysics. Although they intrinsically very rare, ongoing planned wide-field deep-sky surveys set discover thousands of such the next decade. It is thus paramount devise a general framework model strong-lens cope this large influx without being limited by expert investigator time. We propose modelling (implemented publicly available software...
ABSTRACT There is an ≈9 ± 2.5 per cent tension between the value of Hubble’s Constant, H0 = 67.4 0.5 km s−1 Mpc−1, implied by Planck microwave background power spectrum and that given distance scale 73.4 1.7 s−1Mpc−1. But with a plausible assumption about Gaia DR2 parallax systematic offset, we find distances Milky Way Cepheid calibrators are ≈12–15 longer than previously estimated. Similarly, also implies ≈4.7 for 46 Cepheids previous on Riess et al. Then show existence ≈150 h−1Mpc ‘Local...
We describe the selection of galaxies targeted in eight low-redshift clusters (APMCC0917, A168, A4038, EDCC442, A3880, A2399, A119 and A85; 0.029 < z 0.058) as part Sydney-AAO Multi-Object Integral field spectrograph Galaxy Survey (SAMI-GS). have conducted a redshift survey these using AAOmega multi-object on 3.9-m Anglo-Australian Telescope. The is used to determine cluster membership characterize dynamical properties clusters. In combination with existing data, resulted 21 257 reliable...
We present u,b,r & i galaxy number counts and colours both from the North South Hubble Space Telescope Deep Fields William Herschel Field. The latter comprises a 7'x7' area of sky reaching b~28.5 at its deepest. show that simple Bruzual Charlot evolutionary models which assume exponentially increasing star-formation rates with look-back time q_0=0.05 continue to give excellent fits in deep imaging data. With q_0=0.5, an extra population `disappearing dwarf' galaxies is required fit optical...
Using the Prime Focus CCD Camera at Isaac Newton Telescope we have determined form of B and R galaxy number–magnitude count relations in 12 independent fields for |${21}^\text{m}\lt{B}_\text{ccd}\lt{25}^\text{m}\,\text{and}\,{19}^\text{m}\lt{R}_\text{ccd}\lt{23}^\text{m}.5$|. The average lie middle wide range previously encompassed by photographic data. In our data set, find reasonable agreement with counts Tyson these depths. Further, field-to-field variation is small enough to define...
We present new measurements of the luminosity function (LF) Luminous Red Galaxies (LRGs) from Sloan Digital Sky Survey (SDSS) and 2dF-SDSS LRG Quasar (2SLAQ) survey. have carefully quantified, corrected for, uncertainties in K evolutionary corrections, differences colour selection methods, effects photometric errors, thus ensuring we are studying same galaxy population both surveys. Using a limited subset 6326 SDSS LRGs (with 0.17
We present the final spectroscopic QSO catalogue from 2dF-SDSS LRG and (2SLAQ) Survey. This is a deep, 18
We present an analysis of the small-to-intermediate scale clustering samples luminous red galaxies (LRGs) from Sloan Digital Sky Survey (SDSS) and 2dF-SDSS LRG QSO (2SLAQ) survey carefully matched to have same rest-frame colours luminosity. study spatial two-point autocorrelation function in both redshift space [ξ(s)] real [ξ(r)] a combined sample over 10 000 LRGs, which represent most massive universe with stellar masses >1011h−1M⊙ densities ≃10−4h3Mpc−3. find no significant evolution...
We announce the discovery of a new Galactic companion found in data from ESO VST ATLAS survey, and followed up with deep imaging on 4m William Herschel Telescope. The satellite is located constellation Crater (the Cup) at distance $\sim$ 170 kpc. Its half-light radius $r_h=30$ pc its luminosity $M_V=-5.5$. bulk stellar population old metal-poor. would probably have classified newly discovered as an extended globular cluster were it not for presence handful Blue Loop stars sparsely populated...
We present the discovery of two z > 6 quasars, selected as i band dropouts in VST ATLAS survey. Our first quasar has redshift, = 6.31 \pm 0.03, magnitude, z_AB 19.63 0.08 and rest frame 1450A absolute M_1450 -27.8 0.2, making it joint second most luminous known at 6. The 6.02 19.54 -27.0 0.1. also recover a 5.86 discovered by Venemans et al. (2015, prep.). To select our quasars we use new 3D colour space, combining optical colours with mid-infra-red data from Wide-field Infrared Survey...