R. G. McMahon
A5003040118- Astronomy and Astrophysical Research
- Galaxies: Formation, Evolution, Phenomena
- Stellar, planetary, and galactic studies
- Gamma-ray bursts and supernovae
- Astrophysical Phenomena and Observations
- Astronomical Observations and Instrumentation
- Astrophysics and Cosmic Phenomena
- Radio Astronomy Observations and Technology
- Astrophysics and Star Formation Studies
- Adaptive optics and wavefront sensing
- Pulsars and Gravitational Waves Research
- Scientific Research and Discoveries
- Cosmology and Gravitation Theories
- Firm Innovation and Growth
- Geophysics and Gravity Measurements
- Calibration and Measurement Techniques
- History and Developments in Astronomy
- Corporate Finance and Governance
- Private Equity and Venture Capital
- CCD and CMOS Imaging Sensors
- Spectroscopy and Laser Applications
- Entrepreneurship Studies and Influences
- Astro and Planetary Science
- Working Capital and Financial Performance
- X-ray Spectroscopy and Fluorescence Analysis
University of Cambridge
2014-2024
University of Portsmouth
2020
Campbell Collaboration
2019
West Africa Vocational Education
2019
Rhodes University
2018
European Southern Observatory
1997-2016
University of Dundee
2016
NGC Aerospace (Canada)
2016
Carnegie Mellon University
2014
Institute of Astronomy
2001-2012
We report measurements of the mass density, ΩM, and cosmological-constant energy ΩΛ, universe based on analysis 42 type Ia supernovae discovered by Supernova Cosmology Project. The magnitude-redshift data for these supernovae, at redshifts between 0.18 0.83, are fitted jointly with a set from Calán/Tololo Survey, below 0.1, to yield values cosmological parameters. All supernova peak magnitudes standardized using SN light-curve width-luminosity relation. measurement yields joint probability...
We present distance measurements to 71 high redshift type Ia supernovae discovered during the first year of 5-year Supernova Legacy Survey (SNLS). These events were detected and their multi-color light-curves measured using MegaPrime/MegaCam instrument at Canada-France-Hawaii Telescope (CFHT), by repeatedly imaging four one-square degree fields in bands, as part CFHT (CFHTLS). Follow-up spectroscopy was performed VLT, Gemini Keck telescopes confirm nature measure redshift. With this data...
We describe the goals, design, implementation, and initial progress of UKIRT Infrared Deep Sky Survey (UKIDSS), a seven year sky survey which began in May 2005, using Wide Field Camera. It is portfolio five components covering various combinations filter set ZYJHK H_2. The Large Area Survey, Galactic Clusters Plane cover approximately 7000 square degrees to depth K~18; Extragalactic covers 35 K~21, Ultra 0.77 K~23. Summed together UKIDSS 12 times larger effective volume than 2MASS survey....
We have developed a technique to systematically discover and study high-redshift supernovae that can be used measure the cosmological parameters. report here results based on initial seven of more than 28 discovered date in supernova search Supernova Cosmology Project. find an observational dispersion peak magnitudes σMB=0.27; this narrows σMB, corr=0.19 after "correcting" using light-curve "width-luminosity" relation found for nearby (z ≤ 0.1) Type Ia from Calán/Tololo survey (Hamuy et...
The Baryon Oscillation Spectroscopic Survey (BOSS) is designed to measure the scale of baryon acoustic oscillations (BAO) in clustering matter over a larger volume than combined efforts all previous spectroscopic surveys large-scale structure. BOSS uses 1.5 million luminous galaxies as faint i = 19.9 10,000 deg2 BAO redshifts z < 0.7. Observations neutral hydrogen Lyα forest more 150,000 quasar spectra (g 22) will constrain redshift range 2.15 3.5. Early results from include first detection...
This overview paper describes the legacy prospect and discovery potential of Dark Energy Survey (DES) beyond cosmological studies, illustrating it with examples from DES early data.DES is using a wide-field camera (DECam) on 4 m Blanco Telescope in Chile to image 5000 sq deg sky five filters (grizY).
Abstract We report the discovery and monitoring of near-infrared counterpart (AT2017gfo) a binary neutron-star merger event detected as gravitational wave source by Advanced Laser Interferometer Gravitational-wave Observatory (LIGO)/Virgo (GW170817) short gamma-ray burst Fermi Gamma-ray Burst Monitor (GBM) Integral SPI-ACS (GRB 170817A). The evolution transient light is consistent with predictions for behavior “kilonova/macronova” powered radioactive decay massive neutron-rich nuclides...
We present the catalogue, mask, redshift data and selection function for PSCz survey of 15 411 IRAS galaxies across 84 per cent sky. Most are taken from Point Source Catalog, but this has been supplemented corrected in various ways to improve completeness uniformity. quantify known imperfections we assess overall uniformity, quality. find that catalogue is complete uniform within a few at high latitudes 10 low latitudes. Ancillary information, access details, guidelines caveats using given.
Aims. Pointed observations with XMM-Newton provide the basis for creating catalogues of X-ray sources detected serendipitously in each field. This paper describes creation and characteristics 2XMM catalogue.
We present the Data Release 12 Quasar catalog (DR12Q) from Baryon Oscillation Spectroscopic Survey (BOSS) of SDSS-III. This includes all SDSS-III/BOSS objects that were spectroscopically targeted as quasar candidates during full survey and are confirmed quasars via visual inspection spectra, have luminosities Mi[z=2]2.15 is about an order magnitude greater than number z>2.15 known prior to BOSS. Redshifts FWHMs provided for strongest emission lines (CIV, CIII], MgII). The identifies...
We present a catalogue of nearly 3,000 submillimetre sources detected at 850um over ~5 square degrees surveyed as part the James Clerk Maxwell Telescope (JCMT) SCUBA-2 Cosmology Legacy Survey (S2CLS). This is largest survey its kind 850um, probing meaningful cosmic volume peak star formation activity and increasing sample size galaxies selected by an order magnitude. describe wide component S2CLS, which covers key extragalactic fields: UKIDSS-UDS, COSMOS, Akari-NEP, Extended Groth Strip,...
We present the Data Release 9 Quasar (DR9Q) catalog from Baryon Oscillation Spectroscopic Survey (BOSS) of Sloan Digital Sky III. The includes all BOSS objects that were targeted as quasar candidates during survey, are spectrocopically confirmed quasars via visual inspection, have luminosities Mi[z=2]<-20.5 (in a $\Lambda$CDM cosmology with H0 = 70 km/s/Mpc, $\Omega_{\rm M}$ 0.3, and $\Omega_{\Lambda}$ 0.7) either display at least one emission line full width half maximum (FWHM) larger than...
We describe the creation, content, and validation of Dark Energy Survey (DES) internal year-one cosmology data set, Y1A1 GOLD, in support upcoming cosmological analyses. The GOLD set is assembled from multiple epochs DES imaging consists calibrated photometric zeropoints, object catalogs, ancillary products - e.g., maps survey depth observing conditions, star-galaxy classification, redshift estimates that are necessary for accurate wide-area catalog ~137 million objects detected coadded...
We present the Data Release 10 Quasar (DR10Q) catalog from Baryon Oscillation Spectroscopic Survey (BOSS) of Sloan Digital Sky III. The includes all BOSS objects that were targeted as quasar candidates during first 2.5 years survey and are confirmed quasars via visual inspection spectra. also known (mostly SDSS-I II) reobserved by BOSS. contains 166,583 (74,454 new discoveries since SDSS-DR9) detected over 6,373 deg$^{2}$ with robust identification redshift measured a combination principal...
The SDSS-III Baryon Oscillation Spectroscopic Survey (BOSS), a five-year spectroscopic survey of 10,000 deg^2, achieved first light in late 2009. One the key goals BOSS is to measure signature baryon acoustic oscillations distribution Ly-alpha absorption from spectra sample ~150,000 z>2.2 quasars. Along with measuring angular diameter distance at z\approx2.5, will provide direct measurement expansion rate Universe z > 2. biggest challenges achieving this goal an efficient target selection...
Studying quasars at the highest redshifts can constrain models of galaxy and black hole formation, it also probes intergalactic medium in early universe. Optical surveys have to date discovered more than 60 up z~6.4, a limit set by use z-band CCD detectors. Only one z>6.4 quasar has been discovered, namely z=7.08 ULAS J1120+0641, using near-infrared imaging. Here we report discovery three new 332 square degrees Visible Infrared Survey Telescope for Astronomy Kilo-degree Galaxy (VIKING)...
We present the analysis of optical and near-infrared spectra only four $z>6.5$ quasars known to date, discovered in UKIDSS-LAS VISTA-VIKING surveys. Our data-set consists new VLT/X-Shooter Magellan/FIRE observations. These are best optical/NIR spectroscopic data that likely be obtained for sample using current $6$ - $10$ m facilities. estimate black hole mass, Eddington ratio, SiIV/CIV, CIII]/CIV, FeII/MgII emission-line flux ratios. perform spectral modeling a procedure allows us derive...
ABSTRACT We present ALMA detections of the [C ii ] 158 μ m emission line and underlying far-infrared (FIR) continuum three quasars at 6.6 < z 6.9 selected from VIKING survey. The fluxes range between 1.6 3.4 Jy km s −1 ([C luminosities ∼(1.9–3.9) × 10 9 L ⊙ ). measure flux densities 0.56–3.29 mJy around (rest frame), with implied FIR (0.6–7.5) 12 dust masses M d = (0.7–24) 8 . In one quasar we derive a temperature <?CDATA ${30}_{-9}^{+12}$?> <?MML <mml:math> <mml:msubsup> <mml:mrow>...
ABSTRACT We present a blind time-delay cosmographic analysis for the lens system DES J0408−5354. This is extraordinary presence of two sets multiple images at different redshifts, which provide opportunity to obtain more information cost increased modelling complexity with respect previously analysed systems. perform detailed mass distribution this using three band Hubble Space Telescope imaging. combine measured time delays, line-of-sight central velocity dispersion deflector, and...
We present the first constraints on cosmology from Dark Energy Survey (DES), using weak lensing measurements preliminary Science Verification (SV) data. use 139 square degrees of SV data, which is less than 3% full DES survey area. Using cosmic shear 2-point over three redshift bins we find ${\ensuremath{\sigma}}_{8}({\mathrm{\ensuremath{\Omega}}}_{\mathrm{m}}/0.3{)}^{0.5}=0.81\ifmmode\pm\else\textpm\fi{}0.06$ (68% confidence), after marginalizing 7 systematics parameters and 3 other...