A5084769750- Particle physics theoretical and experimental studies
- High-Energy Particle Collisions Research
- Quantum Chromodynamics and Particle Interactions
- Particle Detector Development and Performance
- Astronomy and Astrophysical Research
- Galaxies: Formation, Evolution, Phenomena
- Dark Matter and Cosmic Phenomena
- Gamma-ray bursts and supernovae
- Stellar, planetary, and galactic studies
- Cosmology and Gravitation Theories
- Computational Physics and Python Applications
- Astrophysics and Cosmic Phenomena
- Neutrino Physics Research
- Black Holes and Theoretical Physics
- Astronomical Observations and Instrumentation
- Adaptive optics and wavefront sensing
- Particle Accelerators and Free-Electron Lasers
- CCD and CMOS Imaging Sensors
- Radio Astronomy Observations and Technology
- Scientific Research and Discoveries
- Astro and Planetary Science
- Astrophysical Phenomena and Observations
- Pulsars and Gravitational Waves Research
- Statistical and numerical algorithms
- Distributed and Parallel Computing Systems
Southern Methodist University
2016-2025
Lawrence Berkeley National Laboratory
1999-2020
The University of Adelaide
2019-2020
West University of Timişoara
2020
University of California, Santa Cruz
2018
Centre National de la Recherche Scientifique
1999-2016
Czech Academy of Sciences, Institute of Physics
2000-2016
Charles University
2000-2016
Universidade Federal do ABC
2010-2016
University of Science and Technology of China
2011-2016
Abstract The DESI Legacy Imaging Surveys ( http://legacysurvey.org/ ) are a combination of three public projects (the Dark Energy Camera Survey, the Beijing–Arizona Sky and Mayall z -band Survey) that will jointly image ≈14,000 deg 2 extragalactic sky visible from northern hemisphere in optical bands g , r using telescopes at Kitt Peak National Observatory Cerro Tololo Inter-American Observatory. combined survey footprint is split into two contiguous areas by Galactic plane. imaging...
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 present cosmological results from the measurement of baryon acoustic oscillations (BAO) in galaxy, quasar and Lyman-$\alpha$ forest tracers first year observations Dark Energy Spectroscopic Instrument (DESI), to be released DESI Data Release 1. BAO provide robust measurements transverse comoving distance Hubble rate, or their combination, relative sound horizon, seven redshift bins over 6 million extragalactic objects range $0.1<z<4.2$. data alone are consistent with standard flat...
Abstract Over the next 5 yr, Dark Energy Spectroscopic Instrument (DESI) will use 10 spectrographs with 5000 fibers on 4 m Mayall Telescope at Kitt Peak National Observatory to conduct first Stage IV dark energy galaxy survey. At z < 0.6, DESI Bright Galaxy Survey (BGS) produce most detailed map of universe during dark-energy-dominated epoch redshifts >10 million galaxies spanning 14,000 deg 2 . In this work, we present and validate final BGS target selection survey design. From Legacy...
Abstract We describe the spectroscopic data processing pipeline of Dark Energy Spectroscopic Instrument (DESI), which is conducting a redshift survey about 40 million galaxies and quasars using purpose-built instrument on 4 m Mayall Telescope at Kitt Peak National Observatory. The main goal DESI to measure with unprecedented precision expansion history universe baryon acoustic oscillation technique growth rate structure space distortions. Ten spectrographs three cameras each disperse light...
Abstract The Dark Energy Spectroscopic Instrument (DESI) survey will measure large-scale structures using quasars as direct tracers of dark matter in the redshift range 0.9 < z 2.1 and Ly α forests quasar spectra at > 2.1. We present several methods to select candidate for DESI, input photometric imaging three optical bands ( g , r ) from DESI Legacy Imaging Surveys two infrared (W1, W2) Wide-field Infrared Survey Explorer. These were extensively tested during Validation DESI. In this...
Abstract A system of 5020 robotic fiber positioners was installed in 2019 on the Mayall Telescope, at Kitt Peak National Observatory. The robots automatically retarget their optical fibers every 10–20 minutes, each to a precision several microns, with reconfiguration time fewer than 2 minutes. Over next 5 yr, they will enable newly constructed Dark Energy Spectroscopic Instrument (DESI) measure spectra 35 million galaxies and quasars. DESI produce largest 3D map universe date expansion...
Abstract The Dark Energy Spectroscopic Instrument (DESI) will precisely constrain cosmic expansion and the growth of structure by collecting ∼40 million extragalactic redshifts across ∼80% history one-third sky. Emission Line galaxy (ELG) sample, which comprise about all DESI tracers, be used to probe universe over 0.6 < z 1.6 range, including 1.1 is expected provide tightest constraints. We present target selection for Survey Validation (SV) Main ELG samples, relies on imaging Legacy...
We describe the Milky Way Survey (MWS) that will be undertaken with Dark Energy Spectroscopic Instrument (DESI) on Mayall 4m telescope at Kitt Peak National Observatory. Over next 5 yr DESI MWS observe approximately seven million stars Galactic latitudes |b|>20 degrees, an inclusive target selection scheme focused thick disk and stellar halo. also include several high-completeness samples of rare types, including white dwarfs, low-mass within 100pc Sun, horizontal branch stars. summarize...
Abstract The Dark Energy Spectroscopic Instrument (DESI) survey is a spectroscopic of tens millions galaxies at 0 < z 3.5 covering 14,000 sq. deg. the sky. In its first 1.1 yr operations, it has observed more than 14 million and 4 stars. We describe processes that govern DESI’s observations 15,000 fields composing survey. This includes planning each night’s in afternoon; automatic selection to observe during night; real-time assessment field completeness on basis observing conditions...
Abstract A key component of the Dark Energy Spectroscopic Instrument (DESI) survey validation (SV) is a detailed visual inspection (VI) optical spectroscopic data to quantify metrics. In this paper we present results from VI quasar using deep coadded SV spectra. We show that majority (≈70%) main-survey targets are spectroscopically confirmed as quasars, with ≈16% galaxies, ≈6% stars, and ≈8% low-quality spectra lacking reliable features. nonnegligible fraction quasars misidentified by...
Abstract The Dark Energy Spectroscopic Instrument (DESI) Survey has obtained a set of spectroscopic measurements galaxies to validate the final survey design and target selections. To assist in these tasks, we visually inspect DESI spectra approximately 2500 bright galaxies, 3500 luminous red (LRGs), 10,000 emission-line (ELGs) obtain robust redshift identifications. We then utilize inspected information characterize performance operation. Based on visual inspection (VI) catalogs, our...
Abstract The Dark Energy Spectroscopic Instrument (DESI) is currently measuring the spectra of 40 million galaxies and quasars, largest such survey ever made to probe nature cosmological dark energy. 4 m Mayall telescope at Kitt Peak National Observatory has been adapted for DESI, including construction a 3.°2 diameter prime focus corrector that focuses astronomical light onto 0.8 focal surface with excellent image quality over DESI bandpass 360–980 nm. wide-field includes six lenses, as...
ABSTRACT We present the first comprehensive halo occupation distribution (HOD) analysis of Dark Energy Spectroscopic Instrument (DESI) One-Percent Survey luminous red galaxy (LRG) and Quasi Stellar Object (QSO) samples. constrain HOD each sample test possible extensions by fitting redshift-space 2-point correlation functions in 0.15 &lt; r 32 h−1 Mpc a set fiducial redshift bins. use AbacusSummit cubic boxes at Planck 2018 cosmology as model templates forward clustering with AbacusHOD...
ABSTRACT The 1D power spectrum P1D of the Ly α forest provides important information about cosmological and astrophysical parameters, including constraints on warm dark matter models, sum masses three neutrino species, thermal state intergalactic medium. We present first measurement with quadratic maximum likelihood estimator (QMLE) from Dark Energy Spectroscopic Instrument (DESI) survey early data sample. This sample 54 600 quasars is already comparable in size to largest previous studies,...
Abstract Baryon Acoustic Oscillations can be measured with sub-percent precision above redshift two the Lyman- α (Ly ) forest auto-correlation and its cross-correlation quasar positions. This is one of key goals Dark Energy Spectroscopic Instrument (DESI) which started main survey in May 2021. We present this paper a study contaminants to Ly are mainly caused by correlated signals introduced spectroscopic data processing pipeline as well astrophysical due foreground absorption intergalactic...
Abstract A critical requirement of spectroscopic large scale structure analyses is correcting for selection which galaxies to observe from an isotropic target list. This often limited by the hardware used perform survey will impose angular constraints simultaneously observable targets, requiring multiple passes all them. In SDSS this manifested solely as collision physical fibers and plugs placed in plates. DESI, there additional constraint robotic positioner controls each fiber being a...
ABSTRACT We report evidence for excess blue light from the Type Ia supernova (Sn Ia) SN 2012cg at 15 and 16 days before maximum B -band brightness. The emission is consistent with predictions impact of on a non-degenerate binary companion. This first companion to normal Ia. Sixteen light, <?CDATA $B-V$?> <?MML <mml:math> <mml:mi>B</mml:mi> <mml:mo>−</mml:mo> <mml:mi>V</mml:mi> </mml:math>?> color 0.2 mag bluer than other At later times, this has typical curve, extinction-corrected...
Abstract We present Dark Energy Spectroscopic Instrument (DESI) observations of the inner halo M31, which reveal kinematics a recent merger—a galactic immigration event—in exquisite detail. Of 11,416 sources studied in 3.75 hr on-sky exposure time, 7438 are M31 with well-measured radial velocities. The intricate coherent kinematic structure positions and velocities individual stars: streams, wedges, chevrons. While hints structures have been previously detected this is first time they seen...
Abstract Millions of quasar spectra will be collected by the Dark Energy Spectroscopic Instrument (DESI), leading to a fourfold increase in number known quasars. High-accuracy classification is essential tighten constraints on cosmological parameters measured at highest redshifts DESI observes ( z > 2.0). We present spectral templates for identification and redshift estimation quasars Year 1 data release. The are comprised two eigenspectra sets, trained from Sloan Digital Sky Survey. sets...
ABSTRACT We present the one-dimensional Ly α forest power spectrum measurement using first data provided by Dark Energy Spectroscopic Instrument (DESI). The sample comprises 26 330 quasar spectra, at redshift z &gt; 2.1, contained in DESI Early Data Release and 2 months of main survey. employ a Fast Fourier Transform (FFT) estimator compare resulting to an alternative likelihood-based method companion paper. investigate methodological instrumental contaminants associated with new...
Abstract We detect the cross-correlation between 2.7 million DESI quasar targets across 14,700 deg 2 (180 quasars -2 ) and Planck 2018 CMB lensing at ∼30 σ . use on very large scales to constrain local primordial non-Gaussianity via scale dependence of bias. The lie an effective redshift 1.51 are separated into four imaging regions varying depth image quality. select from Legacy Survey DR9 imaging, apply additional flux photometric cuts improve purity reduce fraction unclassified redshifts,...
Abstract Extreme coronal line emitters (ECLEs) are a rare class of galaxy that exhibit strong, high-ionization iron emission lines in their spectra. In some cases, these transient and may be the result tidal disruption event (TDEs). To test this connection, we calculate rate variable ECLEs (vECLEs) at redshift ∼0.3. We search for Baryon Oscillation Spectroscopic Survey (BOSS) LOWZ sample discover two candidate ECLEs. Using follow-up spectra from Dark Energy Instrument Gemini Multi-Object...