J. P. Willis
A5075993249- Galaxies: Formation, Evolution, Phenomena
- Astronomy and Astrophysical Research
- Astrophysical Phenomena and Observations
- Stellar, planetary, and galactic studies
- Astrophysics and Cosmic Phenomena
- Gamma-ray bursts and supernovae
- Astronomical Observations and Instrumentation
- Adaptive optics and wavefront sensing
- Radio Astronomy Observations and Technology
- Scientific Research and Discoveries
- Astrophysics and Star Formation Studies
- History and Developments in Astronomy
- Space Science and Extraterrestrial Life
- Cosmology and Gravitation Theories
- Solar and Space Plasma Dynamics
- Dark Matter and Cosmic Phenomena
- Advanced Vision and Imaging
- GNSS positioning and interference
- Inertial Sensor and Navigation
- Astro and Planetary Science
- Nuclear physics research studies
- Biotechnology and Related Fields
- Advanced Image Processing Techniques
- Counseling, Therapy, and Family Dynamics
- Utopian, Dystopian, and Speculative Fiction
University of Victoria
2014-2024
Bristol Robotics Laboratory
2018
Jet Propulsion Laboratory
2016
University of Cambridge
1999-2015
Canada–France–Hawaii Telescope
2010
European Southern Observatory
2004
European Southern Observatory
2003-2004
Pontificia Universidad Católica de Chile
2004
Institute of Astronomy
2001
Pontificia Universidad Católica de Valparaíso
2000
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 present a sample of 29 galaxy clusters from the XMM-LSS survey over an area some 5deg2 out to redshift z=1.05. The clusters, which represent about half X-ray identified in region, follow well defined selection criteria and are all spectroscopically confirmed. For we provide luminosities temperatures as masses. cluster distribution peaks around z=0.3 T =1.5 keV, objects being groups with temperature below 2 keV. Our L-T(z) relation points toward self-similar evolution, but does not exclude...
We present a new, K-selected, optical-to-near infrared photometric catalog of the Extended Chandra Deep Field South (ECDFS), making it publicly available to astronomical community.22 The data set is founded on imaging, supplemented by original z'JK imaging collected as part MUltiwavelength Survey Yale–Chile (MUSYC). final consists photometry derived from UU38BVRIz'JK covering full ECDFS, plus H-band for approximately 80% field. 5σ flux limit point sources . This also nominal completeness and...
In the currently debated context of using clusters galaxies as cosmological probes, need for well-defined cluster samples is critical. The XXL Survey has been specifically designed to provide a well characterised sample some 500 X-ray detected suitable studies. main goal present article make public and describe properties catalogue in its state, associated catalogues super-clusters fossil groups. We release containing 365 total. give details follow-up observations explain procedure adopted...
The XMM Large Scale Structure survey (XMM-LSS) is a medium deep large area X-ray survey. Its goal to extend scale structure investigations attempted using ROSAT cluster samples two redshift bins between 0<z<1 while maintaining the precision of earlier studies. Two main goals have constrained design: evolutionary study cluster–cluster correlation function and number density. adopted observing configuration consists an equatorial mosaic 10 ks pointings, separated by covering 8° × 8°, giving...
Context. The XXL Survey is the largest survey carried out by XMM-Newton satellite and covers a total area of 50 square degrees distributed over two fields. It primarily aims at investigating large-scale structures Universe using distribution galaxy clusters active galactic nuclei as tracers matter distribution. will ultimately uncover several hundreds to redshift ~2 sensitivity ~10-14 erg s-1 cm-2 in [0.5–2] keV band.
Context. The XXL Survey is the largest survey carried out by XMM-Newton. Covering an area of 50 deg2, contains ~450 galaxy clusters to a redshift ~2 and X-ray flux limit ~ 5 × 10-15 erg s-1 cm-2. This paper part first release results focussed on bright cluster sample.
Context. We present an estimation of cosmological parameters with clusters galaxies. Aims. constrain the $\Omega_m$, $\sigma_8$, and $w$ from a stand-alone sample X-ray detected in 50 deg$^2$ XMM-XXL survey well-defined selection function. Methods. analyse redshift distribution comprising 178 high S/N out to unity. The cluster scaling relations are determined self-consistent manner. Results. In lambda cold dark matter ($\Lambda$CDM) model, cosmology favoured by XXL compares well results...
We present deep near-infrared JHK imaging of four 10' × fields. The observations were carried out as part the Multiwavelength Survey by Yale-Chile (MUSYC) with ISPI on CTIO 4 m telescope. typical point-source limiting depths are J ∼ 22.5, H 21.5, and K 21 (5 σ; Vega). effective seeing in final images is ∼1.0''. combine these data MUSYC UBVRIz to create K-selected catalogs that unique for their uniform size, depth, filter coverage, image quality. investigate rest-frame optical colors...
The XXL Survey is the largest homogeneous survey carried out with XMM-Newton. Covering an area of 50 deg$^{2}$, contains several hundred galaxy clusters to a redshift $\approx$2 above X-ray flux limit $\sim$5$\times10^{-15}$ erg cm$^{-2}$ s$^{-1}$. This paper belongs first series papers focusing on bright cluster sample. We investigate luminosity-temperature (LT) relation for brightest detected in Survey, taking fully into account selection biases. form LT relation, placing constraints its...
The Virgo Environmental Survey Tracing Ionised Gas Emission (VESTIGE) is a blind narrow-band Halpha+[NII] imaging survey carried out with MegaCam at the Canada-France-Hawaii Telescope. covers whole cluster region from its core to one virial radius (104 deg^2). sensitivity of f(Halpha) ~ 4 x 10^-17 erg sec-1 cm^-2 (5 sigma detection limit) for point sources and Sigma (Halpha) 2 10^-18 sec^-1 arcsec^-2 (1 limit 3 arcsec resolution) extended sources, making VESTIGE deepest largest nearby...
Following the presentation of XMM-LSS X-ray source detection package by Pacaud et al., we provide lists for first 5.5 surveyed square degrees. The catalogues pertain to [0.5-2] and [2-10] keV bands contain in total 3385 point-like or extended sources above a likelihood 15 either band. agreement with deep logN-logS is excellent. main parameters considered are position, countrate, extent associated values. A set additional quantities such as astrometric corrections fluxes further calculated...
The existence of strong lensing systems with Einstein radii covering the full mass spectrum, from <i>∼<i/> (produced by galaxy scale dark matter haloes) to > cluster have long been predicted. Many lenses around and above reported but very few in between. In this article, we present a sample 13 range (or image separations ), i.e. produced <i>galaxy group haloes<i/>. This spans redshift 0.3 0.8. opens new window exploration 10<sup>13<sup/>–10<sup>14<sup/> , crucial for understanding transition...
Context. XMM and Chandra opened a new area for the study of clusters galaxies not only cluster physics, but also detection faint distant that were inaccessible with previous missions.
Distant galaxy clusters provide important tests of the growth large-scale structure in addition to highlighting process evolution a consistently defined environment at large look-back time. We present sample 22 distant (z > 0.8) and cluster candidates selected from 9 deg2 footprint overlapping X-ray Multi Mirror (XMM) Large Scale Structure (LSS), CFHTLS-Wide Spitzer-SWIRE surveys. Clusters are as extended sources with an accompanying overdensity galaxies displaying optical mid-infrared...
This paper presents 52 X-ray bright galaxy clusters selected within the 11 deg$^2$ XMM-LSS survey. 51 of them have spectroscopic redshifts ($0.05<z<1.06$), one is identified at $z_{\rm phot}=1.9$, and all together make high-purity "Class 1" (C1) cluster sample XMM-LSS, highest density with a monitored selection function. Their fluxes, averaged gas temperatures (median $T_X=2$ keV), luminosities $L_{X,500}=5\times10^{43}$ ergs/s) total mass estimates $5\times10^{13} h^{-1} M_{\odot}$) are...
We report the detection of Sunyaev-Zel'dovich (SZ) effect galaxy cluster XLSSU J021744.1-034536, using 30 GHz CARMA data. This was discovered via its extended X-ray emission in XMM-Newton Large Scale Structure survey, precursor to XXL survey. It has a photometrically determined redshift $z=1.91^{+0.19}_{-0.21}$, making it among most distant clusters known, and nominally for which SZ been measured. The spherically integrated Comptonization is $Y_{500}=(3.0\pm0.4)\times 10^{-12}$, measurement...
MSE is an 11.25m aperture observatory with a 1.5 square degree field of view that will be fully dedicated to multi-object spectroscopy. More than 3200 fibres feed spectrographs operating at low (R ~ 2000 - 3500) and moderate 6000) spectral resolution, approximately 1000 fibers high 40000) resolution. designed enable transformational science in areas as diverse tomographic mapping the interstellar intergalactic media; in-situ chemical tagging thick disk halo stars; connecting galaxies their...
We present X-ray and optical spectroscopic observations of 12 galaxy groups clusters identified within the Multi-Mirror (XMM) Large-Scale Structure (LSS) survey. Groups are selected as extended sources from a 3.5 deg2XMM image mosaic above flux limit 8 × 10−15 erg s−1 cm−2 in [0.5–2] keV energy band. Deep BVRI images multi-object spectroscopy confirm each source concentration located redshift interval 0.29 < z 0.56. combine line-of-sight velocity dispersions with properties structure...
We present details of the discovery XLSSJ022303.0-043622, a z=1.2 cluster galaxies. This was identified from its X-ray properties and selected as z>1 candidate optical/near-IR characteristics in XMM Large-Scale Structure Survey (XMM-LSS). It is most distant system discovered survey to date. ground-based optical near IR observations carried out part XMM-LSS survey. The has bolometric luminosity 1.1 +/- 0.7 x 10^44 erg/s, fainter than other known clusters. In it remarkably compact core,...
We present K-band imaging of two ~30'x30' fields covered by the MUSYC Wide NIR Survey. The 1030 and 1255 were imaged with ISPI on 4m Blanco telescope at CTIO to a 5 sigma point-source limiting depth K~20 (Vega). Combining this data Optical UBVRIz imaging, we created multi-band K-selected source catalogs for both fields. These catalogs, together catalog ECDF-S field, used select K<20 BzK galaxies over an area 0.71 deg^2. This is largest ever surveyed galaxies. number counts, redshift...
<i>Aims. <i/>The Ly<i>α<i/> luminosity function (LF) of high-redshift emitters (LAEs) is one the few observables re-ionization epoch accessible with 8–10 m class telescopes. The evolution LAE LF redshift dependent upon physical LAEs and ionisation state Universe towards end Dark Ages.<i>Methods. <i/>We performed a narrow-band imaging program at 1.06 <i>μ<i/>m using CFHT/WIRCam. observations target <i>z<i/> ~ 7.7 in CFHT-LS D1 field. From these we derived photometric sample 7 candidates 7.7....
Aims. Ly-alpha emitters (LAEs) can be detected out to very high redshifts during the epoch of reionization. The evolution LAE luminosity function with redshift is a direct probe transmission intergalactic medium (IGM), and therefore IGM neutral-hydrogen fraction. Measuring (LF) LAEs at z = 7.7 allows us constrain ionizing state Universe this redshift. Methods. We observed three 7.5'x7.5' fields HAWK-I instrument VLT narrow band filter centred 1.06 $\mu$m targeting ~ 7.7. were chosen for...
X-ray extragalactic surveys are ideal laboratories for the study of evolution and clustering active galactic nuclei (AGN). The XXL Survey spans two fields a combined 50 $deg^2$ observed more than 6Ms with XMM-Newton, occupying parameter space between deep very wide area surveys; at same time it benefits from wealth ancillary data. This paper marks first release point source catalogue selected in 2-10 keV energy band limiting flux $F_{2-10keV}=4.8\cdot10^{-14}\rm{erg\,s^{-1}\,cm^{-2}}$. We...