E. S. Rykoff
A5045308614- Galaxies: Formation, Evolution, Phenomena
- Gamma-ray bursts and supernovae
- Astronomy and Astrophysical Research
- Stellar, planetary, and galactic studies
- SAS software applications and methods
- Cosmology and Gravitation Theories
- Astrophysics and Cosmic Phenomena
- CCD and CMOS Imaging Sensors
- Astrophysical Phenomena and Observations
- Astronomical Observations and Instrumentation
- Adaptive optics and wavefront sensing
- Radio Astronomy Observations and Technology
- Dark Matter and Cosmic Phenomena
- Astro and Planetary Science
- Remote Sensing in Agriculture
- Gaussian Processes and Bayesian Inference
- Pulsars and Gravitational Waves Research
- Advanced Image Processing Techniques
- Impact of Light on Environment and Health
- Astrophysics and Star Formation Studies
- Scientific Research and Discoveries
- Calibration and Measurement Techniques
- History and Developments in Astronomy
- Particle Detector Development and Performance
- Advanced Vision and Imaging
SLAC National Accelerator Laboratory
2016-2025
Kavli Institute for Particle Astrophysics and Cosmology
2016-2025
Menlo School
2014-2025
Stanford University
2015-2024
University of Chicago
2021-2023
Campbell Collaboration
2021
Carnegie Mellon University
2021
Centre National de la Recherche Scientifique
2019
Institut d'Astrophysique de Paris
2019
Sorbonne Université
2019
Abstract The Astropy Project supports and fosters the development of open-source openly developed Python packages that provide commonly needed functionality to astronomical community. A key element is core package astropy , which serves as foundation for more specialized projects packages. In this article, we summarize features in recent major release, version 5.0, updates on Project. We then discuss supporting a broader ecosystem interoperable packages, including connections with several...
We describe redMaPPer, a new red sequence cluster finder specifically designed to make optimal use of ongoing and near-future large photometric surveys. The algorithm has multiple attractive features: (1) it can iteratively self-train the model based on minimal spectroscopic training sample, an important feature for high-redshift (2) It handle complex masks with varying depth. (3) produces cluster-appropriate random points enable large-scale structure studies. (4) All clusters are assigned...
We use 26×106 galaxies from the Dark Energy Survey (DES) Year 1 shape catalogs over 1321 deg2 of sky to produce most significant measurement cosmic shear in a galaxy survey date. constrain cosmological parameters both flat ΛCDM and wCDM models, while also varying neutrino mass density. These results are shown be robust using two independent catalogs, photo-z calibration methods, analysis pipelines blind analysis. find 3.5% fractional uncertainty on σ8(Ωm/0.3)0.5=0.782+0.027−0.027 at 68%...
The Northern Sky Variability Survey (NSVS) is a temporal record of the sky over optical magnitude range from 8 to 15.5. It was conducted in course first generation Robotic Optical Transient Search Experiment (ROTSE-I) using robotic system four co-mounted unfiltered telephoto lenses equipped with CCD cameras. survey Los Alamos, NM, and primarily covers entire northern sky. Some data southern fields between declinations 0 -38 deg also available, although fewer epochs noticeably lesser quality....
We report the discovery of eight new ultra-faint dwarf galaxy candidates in second year optical imaging data from Dark Energy Survey (DES). Six these are detected at high confidence, while two lower-confidence identified regions non-uniform survey coverage. The stellar systems found by three independent automated search techniques and as overdensities stars, consistent with isochrone luminosity function an old metal-poor simple population. faint (Mv > -4.7 mag) span a range physical sizes...
We report the discovery of eight new Milky Way companions in optical imaging data collected during first year Dark Energy Survey (DES). Each system is identified as a statistically significant over-density individual stars consistent with expected isochrone and luminosity function an old metal-poor stellar population. The objects span wide range absolute magnitudes (MV from to ), physical sizes (), heliocentric distances (). Based on low surface brightnesses, large sizes, and/or...
We use the abundance and weak-lensing mass measurements of Sloan Digital Sky Survey maxBCG cluster catalog to simultaneously constrain cosmology richness–mass relation clusters. Assuming a flat ΛCDM cosmology, we find σ8(Ωm/0.25)0.41 = 0.832 ± 0.033 after marginalization over all systematics. In common with previous studies, our error budget is dominated by systematic uncertainties, primary two being absolute scale masses clusters, uncertainty in scatter relation. Our constraints are fully...
ABSTRACT We search for excess γ -ray emission coincident with the positions of confirmed and candidate Milky Way satellite galaxies using six years data from Fermi Large Area Telescope (LAT). Our sample 45 stellar systems includes 28 kinematically dark-matter-dominated dwarf spheroidal (dSphs) 17 recently discovered that have photometric characteristics consistent population known dSphs. For each these targets, relative predicted flux due to dark matter annihilation is taken kinematic...
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 present a large catalog of optically selected galaxy clusters from the application new Gaussian Mixture Brightest Cluster Galaxy (GMBCG) algorithm to SDSS Data Release 7 data. The detects by identifying red-sequence plus brightest cluster (BCG) feature, which is unique for and does not exist among field galaxies. Red-sequence clustering in color space detected using an Error Corrected Model. run GMBCG on 8240 deg2 photometric data DR7 assemble largest ever optical catalog, consisting over...
We combine Dark Energy Survey Year 1 clustering and weak lensing data with Baryon Acoustic Oscillations (BAO) Big Bang Nucleosynthesis (BBN) experiments to constrain the Hubble constant. Assuming a flat $\Lambda$CDM model minimal neutrino mass ($\sum m_\nu = 0.06$ eV) we find $H_0=67.2^{+1.2}_{-1.0}$ km/s/Mpc (68% CL). This result is completely independent of constant measurements based on distance ladder, Cosmic Microwave Background (CMB) anisotropies (both temperature polarization), strong...
We describe the creation, content, and validation of Dark Energy Survey (DES) internal year-one cosmology data set, Y1A1 GOLD, in support upcoming cosmological analyses. The GOLD set is assembled from multiple epochs DES imaging consists calibrated photometric zeropoints, object catalogs, ancillary products - e.g., maps survey depth observing conditions, star-galaxy classification, redshift estimates that are necessary for accurate wide-area catalog ~137 million objects detected coadded...
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,...
Abstract This paper presents the third data release of Hyper Suprime-Cam Subaru Strategic Program (HSC-SSP), a wide-field multi-band imaging survey with 8.2 m telescope. HSC-SSP has three layers (Wide, Deep, and UltraDeep) different area coverages depths, designed to address wide array astrophysical questions. from includes 278 nights observing time covers about 670 deg2 in all five broad-band filters (grizy) at full depth (∼26 mag 5σ depending on filter) Wide layer. If we include partially...
We constrain the mass–richness scaling relation of redMaPPer galaxy clusters identified in Dark Energy Survey Year 1 data using weak gravitational lensing. split into 4 × 3 bins richness λ and redshift |$z$| for ≥ 20 0.2 ≤ 0.65 measure mean masses these their stacked lensing signal. By modelling as 〈M200m|λ, |$z$|〉 = M0(λ/40)F((1 + |$z$|)/1.35)G, we normalization at 5.0 per cent level, finding M0 [3.081 ± 0.075(stat) 0.133(sys)] · 1014 M⊙ 40 0.35. The recovered index is F 1.356 0.051 (stat)...
We present two galaxy shape catalogues from the Dark Energy Survey Year 1 data set, covering 1500 square degrees with a median redshift of $0.59$. The cover main fields: Stripe 82, and an area overlapping South Pole Telescope survey region. describe our analysis process in particular measurement using independent shear pipelines, METACALIBRATION IM3SHAPE. catalogue uses Gaussian model innovative internal calibration scheme, was applied to $riz$-bands, yielding 34.8M objects. IM3SHAPE...
We describe the derivation and validation of redshift distribution estimates their uncertainties for populations galaxies used as weak-lensing sources in Dark Energy Survey (DES) Year 1 cosmological analyses. The Bayesian Photometric Redshift (bpz) code is to assign four bins between z ≈ 0.2 ≈1.3, produce initial lensing-weighted distributions |$n^i_{\rm PZ}(z)\propto \mathrm{d}n^i/\mathrm{d}z$| members bin i. Accurate determination parameters depends critically on knowledge ni, but...
We introduce redMaGiC, an automated algorithm for selecting Luminous Red Galaxies (LRGs). The was specifically developed to minimize photometric redshift uncertainties in large-scale structure studies. redMaGiC achieves this by self-training the color-cuts necessary produce a luminosity-thresholded LRG sample of constant comoving density. demonstrate that photozs are very nearly as accurate best machine-learning based methods, yet they require minimal spectroscopic training, do not suffer...
We present weak lensing shear catalogues for 139 square degrees of data taken during the Science Verification (SV) time new Dark Energy Camera (DECam) being used Survey (DES). describe our object selection, point spread function estimation and measurement procedures using two independent pipelines, im3shape ngmix, which produce 2.12 million 3.44 galaxies, respectively. detail a set null tests measurements find that they pass requirements systematic errors at level necessary science...
We describe the Dark Energy Survey (DES) photometric data set assembled from first three years of science operations to support DES Year 3 cosmology analyses, and provide usage notes aimed at broad astrophysics community. Y3 Gold improves on previous releases DES, Y1 Data Release 1 (DES DR1), presenting an expanded curated that incorporates algorithmic developments in image detrending processing, calibration, object classification. comprises nearly 5000 square degrees grizY imaging south...
ABSTRACT We present angular diameter distance measurements obtained by locating the baryon acoustic oscillations (BAO) scale in distribution of galaxies selected from first year Dark Energy Survey data. consider a sample over 1.3 million distributed footprint 1336 deg2 with 0.6 < $z$photo 1 and typical redshift uncertainty 0.03(1 + $z$). This was selected, as fully described companion paper, using colour/magnitude selection that optimizes trade-offs between number density uncertainty....
ABSTRACT We present and characterize the galaxy shape catalogue from first 3 yr of Dark Energy Survey (DES) observations, over an effective area 4143 deg2 southern sky. describe our data analysis process self-calibrating shear measurement pipeline metacalibration, which builds improves upon used in DES Year 1 several aspects. The weak-lensing consists 100 204 026 galaxies, measured riz bands, resulting a weighted source number density neff = 5.59 gal arcmin−2 corresponding noise σe 0.261....
Determining the distribution of redshifts galaxies observed by wide-field photometric experiments like Dark Energy Survey is an essential component to mapping matter density field with gravitational lensing. In this work we describe methods used assign individual weak lensing source from Year 3 Weak Lensing Source Catalogue four tomographic bins and estimate redshift distributions in these bins. As first application data, validate that assumptions made apply DES Y3 develop a full treatment...
We present unfiltered photometric observations with ROTSE-III and optical spectroscopic follow-up the HET Keck of most luminous supernova yet identified, SN 2005ap. The spectra taken about 3 days before 6 after maximum light show narrow emission lines (likely originating in dwarf host) absorption at a redshift z=0.2832, which puts peak magnitude -22.7 +/- 0.1 absolute. Broad P-Cygni features corresponding to H-alpha, CIII, NIII, OIII, are further detected photospheric velocity ~20,000 km/s....
ABSTRACT We show that the projected number density profiles of Sloan Digital Sky Survey photometric galaxies around galaxy clusters display strong evidence for splashback radius, a sharp halo edge corresponding to location first orbital apocenter satellite after their infall. split into two subsamples with different mean radial distances members, <?CDATA $\langle {R}_{{\rm{mem}}}\rangle $?> , at fixed richness and redshift. The sample smaller has ratio radius traditional boundary...