- Gamma-ray bursts and supernovae
- Galaxies: Formation, Evolution, Phenomena
- Astronomy and Astrophysical Research
- Stellar, planetary, and galactic studies
- Astrophysics and Cosmic Phenomena
- Astrophysical Phenomena and Observations
- Cosmology and Gravitation Theories
- Astronomical Observations and Instrumentation
- Adaptive optics and wavefront sensing
- Pulsars and Gravitational Waves Research
- Astrophysics and Star Formation Studies
- Radio Astronomy Observations and Technology
- Geophysics and Gravity Measurements
- Astro and Planetary Science
- Dark Matter and Cosmic Phenomena
- CCD and CMOS Imaging Sensors
- Calibration and Measurement Techniques
- Neutrino Physics Research
- SAS software applications and methods
- History and Developments in Astronomy
- Spectroscopy and Laser Applications
- Scientific Research and Discoveries
- Advanced Image Processing Techniques
- Advanced Vision and Imaging
- Atmospheric Ozone and Climate
Australian National University
2017-2025
American Public University System
2024
Stanford University
2024
Centre National de la Recherche Scientifique
2007-2024
Lowell Observatory
2024
University of Chicago
2024
Canberra (United Kingdom)
2024
Netherlands Institute for Radio Astronomy
2024
Lancaster University
2024
Aix-Marseille Université
2024
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...
Aims. We present cosmological constraints from a joint analysis of type Ia supernova (SN Ia) observations obtained by the SDSS-II and SNLS collaborations. The dataset includes several low-redshift samples (z< 0.1), all three seasons (0.05 <z< 0.4), years (0.2 1), it totals 740 spectroscopically confirmed supernovae with high-quality light curves.
We present Advanced Camera for Surveys, NICMOS, and Keck adaptive-optics-assisted photometry of 20 Type Ia supernovae (SNe Ia) from the Hubble Space Telescope (HST) Cluster Supernova Survey. The SNe were discovered over redshift interval 0.623 < z 1.415. Of these Ia, 14 pass our strict selection cuts are used in combination with world's sample to derive best current constraints on dark energy. new 10 beyond = 1, thereby nearly doubling statistical weight HST-discovered this redshift. Our...
We report measurements of ΩM, ΩΛ, and w from 11 supernovae (SNe) at z = 0.36-0.86 with high-quality light curves measured using WFPC2 on the Hubble Space Telescope (HST). This is an independent set high-redshift SNe that confirms previous SN evidence for accelerating universe. The available photometry make it possible these alone to provide cosmological parameters comparable in statistical weight results. Combined earlier Supernova Cosmology Project data, new yield a measurement mass density...
We present a new compilation of Type Ia supernovae (SNe Ia), dataset low-redshift nearby-Hubble-flow SNe and analysis procedures to work with these heterogeneous compilations. This ``Union'' 414 SN Ia, which reduces 307 after selection cuts, includes the recent large samples from Supernova Legacy Survey ESSENCE Survey, older datasets, as well recently extended distant observed HST. A single, consistent blind procedure is used for all various subsamples, implemented that consistently weights...
We report on work to increase the number of well-measured Type Ia supernovae (SNe Ia) at high redshifts. Light curves, including signal-to-noise Hubble Space Telescope data, and spectra six SNe that were discovered during 2001, are presented. Additionally, for two with z > 1, we present ground-based J-band photometry from Gemini Very Large Telescope. These among most distant which near-IR observations have been obtained. add these together other data sets recently become available in...
We combine high redshift Type Ia supernovae from the first 3 years of Supernova Legacy Survey (SNLS) with other supernova (SN) samples, primarily at lower redshifts, to form a high-quality joint sample 472 SNe (123 low-$z$, 93 SDSS, 242 SNLS, and 14 {\it Hubble Space Telescope}). SN data alone require cosmic acceleration >99.9% confidence, including systematic effects. For dark energy equation state parameter (assumed constant out least $z=1.4$) in flat universe, we find $w =...
We present the first cosmology results from large-scale structure in Dark Energy Survey (DES) spanning 5000 deg$^2$. perform an analysis combining three two-point correlation functions (3$\times$2pt): (i) cosmic shear using 100 million source galaxies, (ii) galaxy clustering, and (iii) cross-correlation of with lens positions. The was designed to mitigate confirmation or observer bias; we describe specific changes made sample following unblinding results. model data within flat $\Lambda$CDM...
We present a joint cosmological analysis of weak gravitational lensing observations from the Kilo-Degree Survey (KiDS-1000), with redshift-space galaxy clustering Baryon Oscillation Spectroscopic (BOSS), and galaxy-galaxy overlap between KiDS-1000, BOSS spectroscopic 2-degree Field Lensing (2dFLenS). This combination large-scale structure probes breaks degeneracies parameters for individual observables, resulting in constraint on growth parameter $S_8=\sigma_8 \sqrt{\Omega_{\rm m}/0.3} =...
We present photometric properties and distance measurements of 252 high redshift Type Ia supernovae (0.15 < z 1.1) discovered during the first three years Supernova Legacy Survey (SNLS). These events were detected their multi-colour light curves measured using MegaPrime/MegaCam instrument at Canada-France-Hawaii Telescope (CFHT), by repeatedly imaging four one-square degree fields in bands. Follow-up spectroscopy was performed VLT, Gemini Keck telescopes to confirm nature measure redshifts....
We present observational constraints on the nature of dark energy using Supernova Legacy Survey three-year sample (SNLS3) Guy et al. and Conley use 472 Type Ia supernovae (SNe Ia) in this sample, accounting for recently discovered correlations between SN luminosity host galaxy properties, include effects all identified systematic uncertainties directly cosmological fits. Combining SNLS3 data with full WMAP7 power spectrum, Sloan Digital Sky luminous red a prior Hubble constant H0 from SHOES,...
(Abridged) Precision cosmology with Type Ia supernovae (SNe Ia) makes use of the fact that SN luminosities depend on their light-curve shapes and colours. Using Supernova Legacy Survey (SNLS) other data, we show there is an additional dependence global characteristics host galaxies: events same shape colour are, average, 0.08mag (~4.0sigma) brighter in massive galaxies (presumably metal-rich) low specific star-formation rates (sSFR). SNe a sSFR also have smaller slope ("beta") between...
ABSTRACT We describe updates to the redMaPPer algorithm, a photometric red-sequence cluster finder specifically designed for large surveys. The updated algorithm is applied of Science Verification (SV) data from Dark Energy Survey (DES), and Sloan Digital Sky (SDSS) DR8 set. DES SV catalog locally volume limited contains 786 clusters with richness (roughly equivalent ) . consists 26,311 , sharply increasing threshold as function redshift performance both catalogs shown be excellent,...
We perform a combined analysis of cosmic shear tomography, galaxy-galaxy lensing and redshift-space multipole power spectra (monopole quadrupole) using 450 deg$^2$ imaging data by the Kilo Degree Survey (KiDS) overlapping with two spectroscopic surveys: 2-degree Field Lensing (2dFLenS) Baryon Oscillation Spectroscopic (BOSS). restrict spectrum measurements to regions KiDS, self-consistently compute full covariance between different observables large suite $N$-body simulations. methodically...
We present the XXL Survey, largest XMM programme totaling some 6.9 Ms to date and involving an international consortium of roughly 100 members. The Survey covers two extragalactic areas 25 deg2 each at a point-source sensitivity ~ 5E-15 erg/sec/cm2 in [0.5-2] keV band (completeness limit). survey's main goals are provide constraints on dark energy equation state from space-time distribution clusters galaxies serve as pathfinder for future, wide-area X-ray missions. review science objectives,...
We evaluate the effects of environment and stellar mass on galaxy properties at 0.85 < z 1.20 using a 3.6um-selected spectroscopic sample 797 cluster field galaxies drawn from GCLASS survey. confirm that for with LogM* > 9.3 well-known correlations between such as star-forming fraction (f_SF), SFR, SSFR, D(4000), color are already in place ~ 1. separate by comparing quiescent fixed environment, mass. The SSFR is correlated mass; however, it independent environment. same trend exists D(4000)...
We present an improved measurement of the Hubble constant (H_0) using 'inverse distance ladder' method, which adds information from 207 Type Ia supernovae (SNe Ia) Dark Energy Survey (DES) at redshift 0.018 < z 0.85 to existing measurements 122 low (z 0.07) SNe (Low-z) and Baryon Acoustic Oscillations (BAOs). Whereas traditional H_0 with use a ladder parallax Cepheid variable stars, inverse relies on absolute BAOs calibrate intrinsic magnitude Ia. find = 67.8 +/- 1.3 km s-1 Mpc-1...