Richard S. Ellis
A5079173006- Astronomy and Astrophysical Research
- Galaxies: Formation, Evolution, Phenomena
- Stellar, planetary, and galactic studies
- Gamma-ray bursts and supernovae
- Astrophysics and Star Formation Studies
- Astronomical Observations and Instrumentation
- Adaptive optics and wavefront sensing
- Astrophysical Phenomena and Observations
- Astrophysics and Cosmic Phenomena
- History and Developments in Astronomy
- Radio Astronomy Observations and Technology
- Cosmology and Gravitation Theories
- Scientific Research and Discoveries
- Pulsars and Gravitational Waves Research
- Stochastic processes and statistical mechanics
- Astro and Planetary Science
- CCD and CMOS Imaging Sensors
- Statistical Mechanics and Entropy
- Theoretical and Computational Physics
- Dark Matter and Cosmic Phenomena
- Markov Chains and Monte Carlo Methods
- Advanced Thermodynamics and Statistical Mechanics
- Spectroscopy and Laser Applications
- Stochastic processes and financial applications
- Geophysics and Gravity Measurements
University College London
2016-2025
Highland Community College - Illinois
2024
University of Tennessee at Knoxville
2024
University of Copenhagen
2024
Center for Surveillance, Epidemiology, and Laboratory Services
2024
University of Massachusetts Amherst
2003-2023
Auckland University of Technology
2022-2023
Durham Technical Community College
2023
Ohio University
2023
Historical Society of Western Pennsylvania
2023
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...
The 2dF Galaxy Redshift Survey (2dFGRS) is designed to measure redshifts for approximately 250-000 galaxies. This paper describes the survey design, spectroscopic observations, redshift measurements and data base. 2dFGRS uses multifibre spectrograph on Anglo-Australian Telescope, which capable of observing 400 objects simultaneously over a 2° diameter field. source catalogue revised extended version APM galaxy catalogue, targets are galaxies with extinction-corrected magnitudes brighter than...
We present a power-spectrum analysis of the final 2dF Galaxy Redshift Survey (2dFGRS), employing direct Fourier method. The sample used comprises 221 414 galaxies with measured redshifts. investigate in detail modelling selection, improving on previous treatments number respects. A new angular mask is derived, based revisions to photometric calibration. redshift selection function determined by dividing survey according rest-frame colour, and deducing self-consistent treatment k-corrections...
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 analyze star formation (SF) as a function of stellar mass (M*) and redshift z in the All-Wavelength Extended Groth Strip International Survey. For 2905 field galaxies, complete to 1010(1010.8) M☉ at < 0.7(1), with Keck spectroscopic redshifts out = 1.1, we compile SF rates (SFRs) from emission lines, GALEX, Spitzer MIPS 24 μm photometry, optical-NIR M* measurements, HST morphologies. Galaxies reliable signs form distinct "main sequence" (MS), limited range SFRs given (1 σ ≲ ±0.3 dex),...
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 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...
Using traditional morphological classifications of galaxies in 10 intermediate-redshift (z~0.5) clusters observed with WFPC-2 on the Hubble Space Telescope, we derive relations between morphology and local galaxy density similar to that found by Dressler for low-redshift clusters. Taken collectively, `morphology-density' relationship, M-D, these more distant, presumably younger is qualitatively sample, but a detailed comparison shows two substantial differences: (1) For our M-D relation...
Formulation of Large Deviation Theory in Terms the Laplace Principle. First Example: Sanov's Theorem. Second Mogulskii's Representation Formulas for Other Stochastic Processes. Compactness and Limit Properties Random Walk Model. Principle Model with Continuous Statistics. Discontinuous Empirical Measures a Markov Chain. Extensions Continuous-Time Processes Appendices. Bibliography. Indexes.
We combine the Two Micron All Sky Survey (2MASS) Extended Source Catalogue and 2dF Galaxy Redshift to produce an infrared selected galaxy catalogue with 17 173 measured redshifts. use this extensive data set estimate luminosity functions in J- KS-bands. The are fairly well fitted by Schechter parameters MJ*−5 log h = −22.36±0.02, αJ −0.93±0.04, ΦJ* 0.0104±0.0016 h3 Mpc−3 J-band MKS*−5 −23.44±0.03, αKS −0.96±0.05, ΦKS* 0.0108±0.0016 KS-band (2MASS Kron magnitudes). These derived assuming a...
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 discuss new constraints on the epoch of cosmic reionization and test assumption that most ionizing photons responsible arose from high redshift star-forming galaxies. Good progress has been made in charting end through spectroscopic studies z~6-8 QSOs, gamma-ray bursts galaxies expected to host Lyman-alpha emission. However, stringent its duration have come integrated optical depth, tau, Thomson scattering microwave background. Using latest data abundance luminosity distribution distant...
We present imaging data and photometry for the COSMOS survey in 15 photometric bands between 0.3 2.4 μm. These include taken on Subaru 8.3 m telescope, KPNO CTIO 4 telescopes, CFHT 3.6 telescope. Special techniques are used to ensure that relative calibration is better than 1% across field of view. The absolute accuracy from standard-star measurements found be 6%. corrected using galaxy spectra, providing colors accurate 2% or better. Stellar counts agree well with expected values. Finally,...
We present a detailed analysis of the spectroscopic catalog galaxies in 10 distant clusters from Dressler et al. (1999, D99). investigate nature different spectral classes defined by D99 including star forming, post-starburst and passive galaxy populations, reproduce their basic properties using our synthesis model. attempt to identify evolutionary pathways between various order search for progenitors numerous galaxies. The comparison spectra populations with samples drawn local Universe...
We compute the bispectrum of 2dF Galaxy Redshift Survey (2dFGRS) and use it to measure bias parameter galaxies. This quantifies strength clustering galaxies relative mass in Universe. By analysing 80 × 106 triangle configurations wavenumber range 0.1 < k 0.5 h Mpc−1 (i.e. on scales roughly between 5 30 h−1 Mpc) we find that linear is consistent with unity: b1= 1.04 ± 0.11, quadratic (non-linear) zero: b2=−0.054 0.08. Thus, at least large scales, optically selected do indeed trace underlying...
We characterize the mass-dependent evolution of more than 8000 galaxies using spectroscopic redshifts from DEEP2 Galaxy Redshift Survey in range 0.4 < z 1.4 and stellar masses calculated K-band photometry obtained at Palomar Observatory. This sample spans 1.5 deg2 four independent fields. Using rest-frame U - B color [O II] equivalent widths, we distinguish star-forming passive populations order to explore nature ``downsizing''—a pattern which sites active star formation shift high-mass...
The Spitzer-COSMOS survey (S-COSMOS) is a Legacy program (Cycles 2+3) designed to carry out uniform deep of the full 2 sq deg COSMOS field in all seven Spitzer bands (3.6, 4.5, 5.6, 8.0, 24.0, 70.0, 160.0 u). This paper describes parameters, mapping strategy, data reduction procedures, achieved sensitivities date, and complete set for future reference. We show that observed infrared backgrounds S-COSMOS are within 10% predicted background levels. fluctuations at 24u have been measured do not...