A. Fausti Neto
A5107345153- Galaxies: Formation, Evolution, Phenomena
- Astronomy and Astrophysical Research
- Gamma-ray bursts and supernovae
- Stellar, planetary, and galactic studies
- Cosmology and Gravitation Theories
- CCD and CMOS Imaging Sensors
- Astrophysics and Cosmic Phenomena
- Astrophysics and Star Formation Studies
- Astronomical Observations and Instrumentation
- Dark Matter and Cosmic Phenomena
- Astrophysical Phenomena and Observations
- Adaptive optics and wavefront sensing
- Impact of Light on Environment and Health
- Radio Astronomy Observations and Technology
- Pulsars and Gravitational Waves Research
- Remote Sensing in Agriculture
- Space Satellite Systems and Control
- Aging and Gerontology Research
- Crop Yield and Soil Fertility
- Gaussian Processes and Bayesian Inference
- Advanced Image Processing Techniques
- Rice Cultivation and Yield Improvement
- Particle Detector Development and Performance
- Stroke Rehabilitation and Recovery
- Calibration and Measurement Techniques
Laboratório Interinstitucional de e-Astronomia
2012-2018
Texas A&M University
2016
The Ohio State University
2016
Fermi National Accelerator Laboratory
2014-2016
Mitchell Institute
2016
Durham University
2007
Universidade Federal do Rio Grande do Sul
2007
We use the Millennium Simulation (MS) to study statistics of LCDM halo concentrations at z = 0. Our results confirm that average concentration declines monotonically with mass; a power-law fits well concentration-mass relation for over 3 decades in mass, up most massive objects form universe (~ 10^15 h^-1 Msol). This is clear disagreement predictions model proposed by Bullock et al. these rare objects, and agrees better original Navarro, Frenk, & White. The large volume surveyed, together...
Abstract We describe the first public data release of Dark Energy Survey, DES DR1, consisting reduced single-epoch images, co-added source catalogs, and associated products services assembled over 3 yr science operations. DR1 is based on optical/near-infrared imaging from 345 distinct nights (2013 August to 2016 February) by Camera mounted 4 m Blanco telescope at Cerro Tololo Inter-American Observatory in Chile. wide-area survey covering ∼5000 deg 2 southern Galactic cap five broad...
The Dark Energy Camera is a new imager with 22 diameter field of view mounted at the prime focus Victor M. Blanco 4 m telescope on Cerro Tololo near La Serena, Chile. camera was designed and constructed by Survey Collaboration meets or exceeds stringent requirements for wide-field supernova surveys which collaboration uses it. consists five-element optical corrector, seven filters, shutter 60 cm aperture, charge-coupled device (CCD) focal plane 250 μm thick fully depleted CCDs cooled inside...
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...
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...
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...
Due to their proximity, high dark-matter content, and apparent absence of non-thermal processes, Milky Way dwarf spheroidal satellite galaxies (dSphs) are excellent targets for the indirect detection dark matter. Recently, eight new dSph candidates were discovered using first year data from Dark Energy Survey (DES). We searched gamma-ray emission coincident with positions these objects in six years Fermi Large Area Telescope data. found no significant excesses emission. Under assumption that...
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 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 the first constraints on cosmology from Dark Energy Survey (DES), using weak lensing measurements preliminary Science Verification (SV) data. use 139 square degrees of SV data, which is less than 3% full DES survey area. Using cosmic shear 2-point over three redshift bins we find ${\ensuremath{\sigma}}_{8}({\mathrm{\ensuremath{\Omega}}}_{\mathrm{m}}/0.3{)}^{0.5}=0.81\ifmmode\pm\else\textpm\fi{}0.06$ (68% confidence), after marginalizing 7 systematics parameters and 3 other...
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 present photometric redshift estimates for galaxies used in the weak lensing analysis of Dark Energy Survey Science Verification (DES SV) data. Four model- or machine learning-based methods -- ANNZ2, BPZ calibrated against BCC-Ufig simulations, SkyNet, and TPZ are analysed. For training, calibration, testing these methods, we construct a catalogue spectroscopically confirmed matched DES SV The performance is evaluated spectroscopic catalogue, focusing on metrics relevant analyses, with...
Shear peak statistics has gained a lot of attention recently as practical alternative to the two point for constraining cosmological parameters. We perform shear analysis Dark Energy Survey (DES) Science Verification (SV) data, using weak gravitational lensing measurements from 139 deg$^2$ field. measure abundance peaks identified in aperture mass maps, function their signal-to-noise ratio, range $0<\mathcal S / \mathcal N<4$. To predict counts parameters we use suite $N$-body simulations...
We describe an algorithm for identifying point-source transients and moving objects on reference-subtracted optical images containing artifacts of processing instrumentation. The makes use the supervised machine learning technique known as Random Forest. present results from its in Dark Energy Survey Supernova program (DES-SN), where it was trained using a sample 898,963 signal background events generated by transient detection pipeline. After reprocessing data collected during first DES-SN...
We measure the cross-correlation between galaxy density in Dark Energy Survey (DES) Science Verification data and lensing of cosmic microwave background (CMB) as reconstructed with Planck satellite South Pole Telescope (SPT). When using DES main sample over full redshift range 0.2 < zphot 1.2, a signal is detected at 6σ 4σ SPT , respectively. then divide galaxies into five photometric bins, finding significant (>2σ) detections all bins. Comparing to fiducial cosmology, we find evolution...
We cross-match galaxy cluster candidates selected via their Sunyaev–Zel'dovich effect (SZE) signatures in 129.1 deg2 of the South Pole Telescope 2500d SPT-SZ survey with optically identified clusters from Dark Energy Survey science verification data. identify 25 between 0.1 ≲ z 0.8 union and redMaPPer (RM) samples. RM is an optical finding algorithm that also returns a richness estimate for each cluster. model λ-mass relation following function 〈ln λ|M500〉 ∝ Bλln M500 + Cλln E(z) use masses...
We present Magellan/M2FS, Very Large Telescope/GIRAFFE, and Gemini South/GMOS spectroscopy of the newly discovered Milky Way satellite Reticulum II. Based on spectra 25 Ret II member stars selected from Dark Energy Survey imaging, we measure a mean heliocentric velocity dispersion . The mass-to-light ratio within its half-light radius is , demonstrating that it strongly dark matter-dominated system. Despite spatial proximity to Magellanic Clouds, radial differs LMC SMC by 199 83...
Cosmic voids are usually identified in spectroscopic galaxy surveys, where 3D information about the large-scale structure of Universe is available. Although an increasing amount photometric data being produced, its potential for void studies limited since redshifts induce line-of-sight position errors ≥50 Mpc h−1which can render many undetectable. We present a new finder designed validate it using simulations, and apply to high-quality photo-z redMaGiC sample DES Science Verification data....
We present measurements of weak gravitational lensing cosmic shear two-point statistics using Dark Energy Survey Science Verification data. demonstrate that our results are robust to the choice measurement pipeline, either ngmix or im3shape, and statistic, including both real Fourier-space statistics. Our pass a suite null tests for B-mode contamination direct any dependence functions on set 16 observing conditions galaxy properties, such as seeing, airmass, color, magnitude, etc....
OzDES is a five-year, 100-night, spectroscopic survey on the Anglo-Australian Telescope, whose primary aim to measure redshifts of approximately 2,500 Type Ia supernovae host galaxies over redshift range 0.1 < z 1.2, and derive reverberation-mapped black hole masses for 500 active galactic nuclei quasars 0.3 4.5. This treasure trove data forms major part follow-up Dark Energy Survey which we are also targeting cluster galaxies, radio strong lenses, unidentified transients, as well measuring...
We describe the operation and performance of difference imaging pipeline (DiffImg) used to detect transients in deep images from Dark Energy Survey Supernova program (DES-SN) its first observing season 2013 August through 2014 February. DES-SN is a search for which ten 3 deg2 fields are repeatedly observed g, r, i, z passbands with cadence about 1 week. The strategy has been optimized measure high-quality light curves redshifts thousands Type Ia supernovae (SNe Ia) goal measuring dark energy...
We measure the weak lensing shear around galaxy troughs, i.e. radial alignment of background galaxies relative to underdensities in projections foreground field over a wide range redshift Science Verification data from Dark Energy Survey. Our detection signal is highly significant (10σ–15σ for smallest angular scales) troughs with z ∈ [0.2, 0.5] projected and diameters 10 arcmin…1°. These measurements probe connection between galaxy, matter density, convergence fields. By assuming are biased...
We study the clustering of galaxies detected at i < 22.5 in Science Verification observations Dark Energy Survey (DES). Two-point correlation functions are measured using 2.3 × 106 over a contiguous 116 deg2 region five bins photometric redshift width Δz = 0.2 range z 1.2. The impact errors is assessed by comparing results template-based photo-z algorithm (BPZ) to machine-learning (TPZ). A companion paper presents maps several observational variables (e.g. seeing, sky brightness) which could...
We construct the largest curved-sky galaxy weak lensing mass map to date from DES first-year (DES Y1) data. The map, about 10 times larger than previous work, is constructed over a contiguous ≈1500 deg2, covering comoving volume of ≈10 Gpc3. effects masking, sampling, and noise are tested using simulations. generate maps two Y1 shear catalogues, MetaCalibration Im3shape, with sources at redshift 0.2 < z 1.3, in each four bins this range. In highest signal-to-noise ratio between mean signal...