A5033210561- Astronomy and Astrophysical Research
- Gamma-ray bursts and supernovae
- Stellar, planetary, and galactic studies
- Galaxies: Formation, Evolution, Phenomena
- Astronomical Observations and Instrumentation
- Astrophysics and Cosmic Phenomena
- Astrophysical Phenomena and Observations
- Astrophysics and Star Formation Studies
- Astro and Planetary Science
- Pulsars and Gravitational Waves Research
- Scientific Research and Discoveries
- Adaptive optics and wavefront sensing
- Radio Astronomy Observations and Technology
- History and Developments in Astronomy
- Cosmology and Gravitation Theories
- Calibration and Measurement Techniques
- CCD and CMOS Imaging Sensors
- Algebraic and Geometric Analysis
- Thyroid Disorders and Treatments
- Mathematics and Applications
- Fault Detection and Control Systems
- Black Holes and Theoretical Physics
- Atomic and Subatomic Physics Research
- Solar and Space Plasma Dynamics
- Liver Disease Diagnosis and Treatment
University of Victoria
2006-2024
Université Paris Cité
2007
Laboratoire de Physique Nucléaire et de Hautes Énergies
2007
Institut National de Physique Nucléaire et de Physique des Particules
2007
Sorbonne Université
2007
Centre National de la Recherche Scientifique
2007
California Institute of Technology
2007
Canada–France–Hawaii Telescope
1997-2002
National Academies of Sciences, Engineering, and Medicine
1997-2002
University of Hawaii System
1997-2002
view Abstract Citations (538) References (43) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Galaxy Cluster Virial Masses and Omega Carlberg, R. G. ; Yee, H. K. C. Ellingson, E. Abraham, Gravel, P. Morris, S. Pritchet, J. The mean density of the universe is equal to mass a large galaxy cluster divided by equivalent comoving volume in field from which that originated. To reexamine rich {OMEGA}- value CNOC Survey has observed 16 high X-ray luminosity clusters...
With the advent of large dedicated Type Ia supernova (SN Ia) surveys, K-corrections SNe and their uncertainties have become especially important in determination cosmological parameters. While are largely driven by SN broad-band colors, it is shown here that diversity spectral features can also be important. For an individual observation, statistical errors from inhomogeneity range 0.01 (where observed rest-frame filters aligned) to 0.04 misaligned). To minimize systematic caused assumed...
The average mass density profile measured in the Canadian Network for Observational Cosmology cluster survey is well described with analytic form ρ(r) = Ar-1(r + aρ)-2, as advocated on basis of n-body simulations by Navarro, Frenk, & White. predicted core radii are aρ 0.20 (in units radius where mean interior 200 times critical density) an Ω 0.2 open cold dark matter model and 0.26 a flat model, little dependence other cosmological parameters normalized to observed abundance. dynamically...
We present SiFTO, a new empirical method for modeling Type Ia supernova (SN Ia) light curves by manipulating spectral template. make use of high-redshift SN data when training the model, allowing us to extend it bluer than rest-frame U. This increases utility our observations more available data. find that shape curve is described using stretch prescription, applying same at all wavelengths not an adequate description. SiFTO therefore uses generalization which applies different factors as...
The galaxy merger and accretion rates, their evolution with time, provide important tests for models of formation evolution. Close pairs galaxies are the best available means measuring redshift in these quantities. In this study, we introduce two new pair statistics, which relate close to rates. We demonstrate importance correcting (and other) statistics selection effects related sample depth completeness. particular, highlight severe bias that can result from use a flux-limited survey....
We investigate redshift evolution in the galaxy merger and accretion rates, using a well-defined sample of 4184 galaxies with 0.12 < z 0.55 R_C 21.5. identify 88 close (5 r_p 20 h^{-1} kpc) dynamical (delta v 500 km/s) pairs. These are used to compute global pair statistics, after accounting for selection effects resulting from flux limit, k-corrections, luminosity evolution, spectroscopic incompleteness. find that number companions per (for -21 M_B^{k,e} -18) is Nc = 0.0321 +/- 0.0077 at...
We have conducted a wide-field CCD-mosaic study of the resolved red giant branch stars M31, in field located 20 kpc from nucleus along southeast minor axis. In our (I, V-I) color-magnitude diagram, (RGB) top three magnitudes M31 halo are strongly present. use photometry more distant control to subtract contamination and then derive "cleaned" luminosity function metallicity distribution for this outer-halo region M31. From color foreground Milky Way stars, we find reddening E(V-I) = 0.10 ±...
A redshift sample of 545 field galaxies is used to examine how the galaxy merger rate changes with and mergers affect observed properties in close pairs. Close pairs are defined as those projected separations less than 20 h-1 kpc. At a mean 0.33, it found that 7.1% ± 1.4% physical pairs, compared 4.3% 0.4% locally. The estimated change (1 + z)2.8±0.9. These results shown be consistent previous close-pair studies provide one strongest constraints date on dependence rate.
We present the photometric calibration of Supernova Legacy Survey (SNLS) fields. The SNLS aims at measuring distances to SNe Ia (0.3<z<1) using MegaCam, 1 deg^2 imager on Canada-France-Hawaii Telescope (CFHT). uncertainty affecting survey dominates systematic key measurement survey, namely dark energy equation state. requires obtaining a uniform response across imager, calibrating science field stars in each band (SDSS-like ugriz bands) with respect standards known flux same bands, and...
We present a measurement of the volumetric rate superluminous supernovae (SLSNe) at z~1, measured using archival data from first four years Canada-France-Hawaii Telescope Supernova Legacy Survey (SNLS). develop method for photometric classification SLSNe to construct our sample. Our sample includes two previously spectroscopically-identified objects, and further new candidate selected technique. use point-source recovery efficiencies Perrett et.al. (2010) Monte Carlo approach calculate based...
We present CCD photometry for the gravitationally lensed quasar system 2237+0305, in optical passbands from B through R, taken over a time period of more than 3 yr. These data provide new information about probable microlensing event reported Irwin et al. [AJ, 98, 1989 (1989)]; rise this feature is approximately 26 days. Four additional independent brightness changes images are detected.
Type Ia supernovae (SNe Ia) occur in both old, passive galaxies and active, star-forming galaxies. This fact, coupled with the strong dependence of SN rate on star formation rate, suggests that SNe form from stars a wide range ages. Here we show explosions is about 1% stellar death independent history. The implies delay time distribution proportional to t−0.5 ± 0.2. single-degenerate channel for can be made match observed rate-SFR relation, but only if white dwarfs are converted uniform...
This paper exploits the gravitational magnification of Type Ia supernovae (SNe Ia) to measure properties dark matter haloes. Gravitationally magnified and de-magnified SNe should be brighter fainter than average, respectively. The individual can computed using observed foreground galaxies halo models. We model haloes as truncated singular isothermal spheres with velocity dispersion truncation radius obeying luminosity-dependent scaling laws.
If a galaxy cluster is effectively in dynamical equilibrium then all populations within the must have distributions velocity and position that individually reflect same underlying mass distribution, although derived virial masses can be quite different. Specifically, CNOC sample radius of red population is, on average, factor $2.05 \pm 0.34$ smaller than blue population. The galaxies also RMS dispersion, $1.31 0.13$ our sample. Consequently, calculated from $3.5 1.3$ times larger galaxies....
Isolated examples of young star-forming galaxies have been discovered, but the predicuted widespread population primeval (estimated to surface densities in range 104-5 deg-2) has so far escaped detection. This paper deals with search for this extensive (and, far, elusive) population, and concentrates on formation spheroidal systems (bulges halos) since there is considerable evidence that disk was more quiescent. The review begins a summary expected model independent properties galaxies....
Counts of stars near the tip red giant branch have been used to estimate surface brightness halo M31 down a level μ_V_~30 mag arcsec^-2^ (R~20 kpc). Over range 0.2<~R(kpc)<~20 distribution in Andromeda galaxy is well-represented by single de Vaucouleurs law. Alternatively, outer can also be modelled power-law density form p(R)is proportional R^-5^. This result suggests that globular cluster component (for which p R^-3^) more extended than stellar this galaxy. At μ_V_ ~ 28 (R~10 kpc), axial...
We compare the rise times of nearby and distant Type Ia supernovae (SNe Ia) as a test for evolution using 73 high-redshift spectroscopically-confirmed SNe from first two years five year Supernova Legacy Survey (SNLS) published observations SN. Because ``rolling'' search nature SNLS, our measurement is approximately 6 more precise than previous studies, allowing sensitive between supernovae. Adopting simple $t^2$ early-time model (as in studies), we find that rest-frame $B$ fiducial SN at...
We present ultraviolet (UV) spectroscopy and photometry of four Type Ia supernovae (SNe 2004dt, 2004ef, 2005M, 2005cf) obtained with the UV prism Advanced Camera for Surveys on Hubble Space Telescope. This data set provides unique spectral time series down to 2000 Å. Significant diversity is seen in near-maximum-light spectra (∼2000–3500 Å) this small sample. The corresponding photometric data, together archival from Swift Ultraviolet/Optical Telescope observations, provide further evidence...
We present a measurement of the volumetric Type Ia supernova (SN Ia) rate (SNR_Ia) as function redshift for first four years data from Canada-France-Hawaii Telescope (CFHT) Supernova Legacy Survey (SNLS). This analysis includes 286 spectroscopically confirmed and more than 400 additional photometrically identified SNe within range 0.1<z<1.1. The SNR_Ia evolution is consistent with rise to z~1.0 that follows power-law form (1+z)^alpha, alpha=2.11+/-0.28. evolutionary trend in SNLS rates...
This paper describes the results of a survey internal kinematics intermediate-redshift (z = 0.25-0.45) field galaxies. Spatially resolved spectra [O II] λλ3726, 3729 doublet emission line have been obtained for 22 galaxies at Canada-France-Hawaii Telescope. High spatial resolution has made it possible to extract Vrot sin i and disk scale lengths from each galaxy spectrum using synthetic rotation curve fitting. About 25% in sample unrelated rotation. is concentrated nucleus these...
view Abstract Citations (91) References (41) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Evidence for Steep Luminosity Functions in Clusters of Galaxies de Propris, Roberto ; Pritchet, Christopher J. Harris, William E. McClure, Robert D. functions have been obtained very faint dwarf galaxies the cores four rich clusters (Abell 2052, Abell 2107, 2199, and 2666). It is found that luminosity function rises steeply these with a power-law slope α ∼ -2.2...
NGC 4494, a large elliptical galaxy, and 4565, an edge-on Sb spiral similar in size to M31 the Milky Way, have usually been regarded as members of Coma I group galaxies at d~10 Mpc. We present new V- band CCD photometry globular cluster systems around both these galaxies, use data test whether or not two are indeed same group. Our luminosity function (GCLF) yields distance moduli for (m -M)_0_ = 30.8+/-0.4 (NGC 4494) - M)_0_ 30.00+/-0.30 4565), which suggest that they physical 4565 is I,...