J. T. A. de Jong
A5027374101- Astronomy and Astrophysical Research
- Galaxies: Formation, Evolution, Phenomena
- Stellar, planetary, and galactic studies
- Gamma-ray bursts and supernovae
- Astronomical Observations and Instrumentation
- Adaptive optics and wavefront sensing
- Astrophysics and Star Formation Studies
- Cosmology and Gravitation Theories
- Pulsars and Gravitational Waves Research
- CCD and CMOS Imaging Sensors
- Astrophysics and Cosmic Phenomena
- History and Developments in Astronomy
- Solar and Space Plasma Dynamics
- Historical Astronomy and Related Studies
- SAS software applications and methods
- Astro and Planetary Science
- Geophysics and Gravity Measurements
- Astrophysical Phenomena and Observations
- Advanced Vision and Imaging
- Particle Detector Development and Performance
- Remote Sensing in Agriculture
- Black Holes and Theoretical Physics
- Historical, Religious, and Philosophical Studies
- Nuclear Physics and Applications
- Geomagnetism and Paleomagnetism Studies
Leiden University
2012-2024
University of Groningen
2005-2024
University of Hull
2023
Leiden Observatory
2012-2017
Astronomy and Space
2005-2015
Max Planck Institute for Astronomy
2006-2011
Max Planck Society
2008
Netherlands Institute for Radio Astronomy
2004
Astronomical Institute of the Slovak Academy of Sciences
2000
We present cosmological parameter constraints from a tomographic weak gravitational lensing analysis of ~450deg$^2$ imaging data the Kilo Degree Survey (KiDS). For flat $\Lambda$CDM cosmology with prior on $H_0$ that encompasses most recent direct measurements, we find $S_8\equiv\sigma_8\sqrt{\Omega_{\rm m}/0.3}=0.745\pm0.039$. This result is in good agreement other low redshift probes large scale structure, including cosmic shear results, along pre-Planck microwave background constraints. A...
We present five new satellites of the Milky Way discovered in Sloan Digital Sky Survey (SDSS) imaging data, four which were followed up with either Subaru or Isaac Newton Telescopes. They include probable dwarf galaxies—one each constellations Coma Berenices, Canes Venatici, Leo, and Hercules—together one unusually extended globular cluster, Segue 1. provide distances, absolute magnitudes, half-light radii, color-magnitude diagrams for all satellites. The morphological features are generally...
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 have used data from the Sloan Digital Sky Survey (SDSS) Data Release 5 to explore overall structure and substructure of stellar halo Milky Way using about 4 million color-selected main sequence turn-off stars. fit oblate triaxial broken power-law models data, found a `best-fit' oblateness 0.5~100pc, after accounting for (known) contribution Poisson uncertainties. The fractional RMS deviation actual distribution any smooth, parameterized model is >~40%: hence, highly structured....
We derive the structural parameters of recently discovered very low luminosity Milky Way satellites through a Maximum Likelihood algorithm applied to SDSS data. For each satellite, even when only few tens stars are available down flux limit, yields robust estimates and errors for centroid, position angle, ellipticity, exponential half-light radius number member stars. This latter parameter is then used in conjunction with stellar population models their absolute magnitudes masses, accounting...
The Kilo-Degree Survey (KiDS) is a multi-band imaging survey designed for cosmological studies from weak lensing and photometric redshifts. It uses the European Southern Observatory VLT Telescope with its wide-field camera OmegaCAM. KiDS images are taken in four filters similar to Sloan Digital Sky ugri bands. best seeing time reserved deep r-band observations. median 5σ limiting AB magnitude 24.9 below 0.7 arcsec. Initial observations have concentrated on Galaxy Mass Assembly (GAMA) regions...
Context . The Kilo-Degree Survey (KiDS) is an ongoing optical wide-field imaging survey with the OmegaCAM camera at VLT Telescope, specifically designed for measuring weak gravitational lensing by galaxies and large-scale structure. When completed it will consist of 1350 square degrees imaged in four filters ( ugri ). Aims Here we present fourth public data release which more than doubles area sky covered 3. We also include aperture-matched Z Y J H K s photometry from our partner VIKING on...
The Kilo-Degree Survey (KiDS) is an optical wide-field imaging survey carried out with the VLT Telescope and OmegaCAM camera. KiDS will image 1500 square degrees in four filters (ugri), together its near-infrared counterpart VIKING produce deep photometry nine bands. Designed for weak lensing shape photometric redshift measurements, core science driver of mapping large-scale matter distribution Universe back to a ~0.5. Secondary cases are manifold, covering topics such as galaxy evolution,...
We test extensions to the standard cosmological model with weak gravitational lensing tomography using 450 deg$^2$ of imaging data from Kilo Degree Survey (KiDS). In these extended cosmologies, which include massive neutrinos, nonzero curvature, evolving dark energy, modified gravity, and running scalar spectral index, we also examine discordance between KiDS cosmic microwave background measurements Planck. The two datasets is largely unaffected by a more conservative treatment systematics...
We present a tomographic cosmic shear analysis of the Kilo-Degree Survey (KiDS) combined with VISTA Infrared Galaxy (VIKING). This is first time that full optical to near-infrared data set has been used for wide-field cosmological weak lensing experiment. unprecedented data, spanning $450~$deg$^2$, allows us improve significantly estimation photometric redshifts, such we are able include robustly higher-redshift sources measurement, and - most importantly solidify our knowledge redshift...
In Galaxy And Mass Assembly Data Release 4 (GAMA DR4), we make available our full spectroscopic redshift sample. This includes 248682 galaxy spectra, and, in combination with earlier surveys, results 330542 redshifts across five sky regions covering ~250deg^2. The density, is the highest over such a sustained area, has exceptionally high completeness (95 per cent to r_KIDS=19.65mag), and well suited for study of mergers, groups, low (z<0.25) population. DR4 32 value-added tables or...
We present a joint cosmic shear analysis of the Dark Energy Survey (DES Y3) and Kilo-Degree (KiDS-1000) in collaborative effort between two survey teams. find consistent cosmological parameter constraints DES Y3 KiDS-1000 which, when combined joint-survey analysis, constrain $S_8 = \sigma_8 \sqrt{\Omega_{\rm m}/0.3}$ with mean value $0.790^{+0.018}_{-0.014}$. The marginal is lower than maximum posteriori estimate, $S_8=0.801$, owing to skewness distribution projection effects...
In this Letter, we announce the discovery of a new dwarf galaxy, Leo T, in Local Group. It was found as stellar overdensity Sloan Digital Sky Survey Data Release 5 (SDSS DR5). The color-magnitude diagram T shows two well-defined features, which interpret red giant branch and sequence young, massive stars. As judged from fits to diagram, it lies at distance about 420 kpc has an intermediate-age population with metallicity [Fe/H]= -1.6, together young blue stars age 200 Myr. There is compact...
The Kilo Degree Survey (KiDS) is a 1500 square degree optical imaging survey with the recently commissioned OmegaCAM wide-field imager on VLT Telescope (VST). A suite of data products will be delivered to European Southern Observatory (ESO) and community by KiDS team. Spread over Europe, team uses Astro-WISE as its main tool collaborate efficiently pool hardware resources. In shares, calibrates archives all data. data-centric architectural design realizes dynamic 'live archive' in which new...
We map the stellar structure of Galactic thick disk and halo by applying color-magnitude diagram (CMD) fitting to photometric data from SEGUE survey, allowing, for first time, a comprehensive analysis their at both high low latitudes using uniform SDSS photometry. Incorporating photometry all relevant stars simultaneously, CMD bypasses need choose single tracer populations. Using old populations differing metallicities as templates we obtain sparse 3D mass distribution |Z|>1 kpc. Fitting...
The Kilo-Degree Survey (KiDS) is an optical wide-field survey designed to map the matter distribution in Universe using weak gravitational lensing. In this paper, we use these data measure density profiles and masses of a sample $\sim \mathrm{1400}$ spectroscopically identified galaxy groups clusters from Galaxy And Mass Assembly (GAMA) survey. We detect highly significant signal (signal-to-noise-ratio $\sim$ 120), allowing us study properties dark haloes over one half order magnitude mass,...
We present weak lensing shear catalogues from the fourth data release of Kilo-Degree Survey, KiDS-1000, spanning 1006 square degrees deep and high-resolution imaging. Our `gold-sample' galaxies, with well-calibrated photometric redshift distributions, consists 21 million galaxies an effective number density $6.17$ per arcminute. quantify accuracy spatial, temporal, flux-dependent point-spread function (PSF) model, verifying that model meets our requirements to induce less than a $0.1\sigma$...
Context. The Kilo-Degree Survey (KiDS) is an ongoing optical wide-field imaging survey with the OmegaCAM camera at VLT Telescope. It aims to image 1500 square degrees in four filters (ugri). core science driver mapping large-scale matter distribution Universe, using weak lensing shear and photometric redshift measurements. Further cases include galaxy evolution, Milky Way structure, detection of high-redshift clusters, finding rare sources such as strong lenses quasars.
We present cosmological constraints from a cosmic shear analysis of the fourth data release Kilo-Degree Survey (KiDS-1000), doubling survey area with nine-band optical and near-infrared photometry respect to previous KiDS analyses. Adopting spatially flat $\Lambda$CDM model, we find $S_8 = \sigma_8 (\Omega_{\rm m}/0.3)^{0.5} 0.759^{+0.024}_{-0.021}$ for our fiducial analysis, which is in $3\sigma$ tension prediction Planck Legacy microwave background. compare COSEBIs (Complete Orthogonal...
We describe the selection of galaxies targeted in eight low-redshift clusters (APMCC0917, A168, A4038, EDCC442, A3880, A2399, A119 and A85; 0.029 < z 0.058) as part Sydney-AAO Multi-Object Integral field spectrograph Galaxy Survey (SAMI-GS). have conducted a redshift survey these using AAOmega multi-object on 3.9-m Anglo-Australian Telescope. The is used to determine cluster membership characterize dynamical properties clusters. In combination with existing data, resulted 21 257 reliable...
We report the discovery of two extremely low luminosity globular clusters in Milky Way Halo. These objects were detected Sloan Digital Sky Survey Data Release 5 and confirmed with deeper imaging at Calar Alto Observatory. The clusters, Koposov 1 2, are located $\sim 40-50$ kpc appear to have old stellar populations luminosities only $M_V \sim -1$ mag. Their observed sizes 3$ pc well within expected tidal limit $\sim$10 that distance. Together Palomar 1, AM 4 Whiting these new lowest...
We present the results of our first year quasar search in on-going ESO public Kilo Degree Survey (KiDS) and VISTA Kilo-Degree Infrared Galaxy (VIKING) surveys. These surveys are among deeper wide-field that can be used to uncovered large numbers z~6 quasars. This allows us probe a more common population quasars is fainter than well-studied from main Sloan Digital Sky Survey. From this set combined survey catalogues covering ~250 deg^2 we selected point sources down Z_AB=22 had very red i-Z...
We present a machine-learning photometric redshift (ML photo- z ) analysis of the Kilo-Degree Survey Data Release 3 (KiDS DR3), using two neural-network based techniques: ANNz2 and MLPQNA. Despite limited coverage spectroscopic training sets, these ML codes provide s quality comparable to, if not better than, those from Bayesian Photometric Redshift (BPZ) code, at least up to phot ≲ 0.9 r 23.5. At bright end 20, where very complete data overlapping with KiDS are available, performance...
We present deep, wide-field g and r photometry of the transition type dwarf galaxy Leo T, obtained with blue arm Large Binocular Telescope. The data confirm presence both very young (<1 Gyr) as well much older (>5 stars. study structural properties old stellar populations by preferentially selecting either population based on their color magnitude. is significantly more concentrated than population, half-light radii 104+-8 148+-16 pc respectively, centers are slightly offset....