Chris Stoughton
A5027862992- Astronomy and Astrophysical Research
- Stellar, planetary, and galactic studies
- Galaxies: Formation, Evolution, Phenomena
- Gamma-ray bursts and supernovae
- Particle physics theoretical and experimental studies
- Astronomical Observations and Instrumentation
- Astrophysics and Cosmic Phenomena
- Cosmology and Gravitation Theories
- Astrophysical Phenomena and Observations
- High-Energy Particle Collisions Research
- Radio Astronomy Observations and Technology
- Astrophysics and Star Formation Studies
- Quantum Chromodynamics and Particle Interactions
- Dark Matter and Cosmic Phenomena
- Computational Physics and Python Applications
- Superconducting and THz Device Technology
- Neutrino Physics Research
- Pulsars and Gravitational Waves Research
- CCD and CMOS Imaging Sensors
- Adaptive optics and wavefront sensing
- Particle Accelerators and Free-Electron Lasers
- Quantum Computing Algorithms and Architecture
- Quantum Information and Cryptography
- Atomic and Subatomic Physics Research
- Quantum and electron transport phenomena
Fermi National Accelerator Laboratory
2015-2025
Jet Propulsion Laboratory
2020
Dominican School of Philosophy and Theology
2020
University of California, Santa Barbara
2020
Fermi Research Alliance
2019
Seattle University
2018
Wellesley College
2014
United States Department of Energy
1998-2000
University of Mississippi
1992
Columbia University
1989-1992
The Sloan Digital Sky Survey (SDSS) is an imaging and spectroscopic survey that will eventually cover approximately one-quarter of the celestial sphere collect spectra ≈106 galaxies, 100,000 quasars, 30,000 stars, serendipity targets. In 2001 June, SDSS released to general astronomical community its early data release, roughly 462 deg2 including almost 14 million detected objects 54,008 follow-up spectra. were collected in drift-scan mode five bandpasses (u, g, r, i, z); our 95% completeness...
The spectroscopic Sloan Digital Sky Survey (SDSS) Data Release 7 (DR7) galaxy sample represents the final set of galaxies observed using original SDSS target selection criteria. We analyse clustering within this sample, including both luminous red and main samples, also include 2-degree Field Galaxy Redshift data. In total, comprises 893 319 over 9100 deg2. Baryon acoustic oscillations (BAO) are in power spectra measured for different slices redshift; allows us to constrain distance–redshift...
We have created a variety of composite quasar spectra using homogeneous data set over 2200 from the Sloan Digital Sky Survey (SDSS). The sample spans redshift range 0.044 ≤ z 4.789 and an absolute r' magnitude -18.0 to -26.5. input cover observed wavelength 3800–9200 Å at resolution 1800. median covers rest-wavelength 800 8555 reaches peak signal-to-noise ratio 300 per 1 element in rest frame. identified 80 emission-line features spectrum. Emission-line shifts relative nominal laboratory...
The Sloan Extension for Galactic Understanding and Exploration (SEGUE) Survey obtained ≈240,000 moderate-resolution (R ∼ 1800) spectra from 3900 Å to 9000 of fainter Milky Way stars (14.0 < g 20.3) a wide variety spectral types, both main-sequence evolved objects, with the goal studying kinematics populations our Galaxy its halo. are clustered in 212 regions spaced over three quarters sky. Radial velocity accuracies at 18, degrading 20. For signal-to-noise ratio >10 per resolution element,...
We describe the algorithm for selecting quasar candidates optical spectroscopy in Sloan Digital Sky Survey. Quasar are selected via their non-stellar colors "ugriz" broad-band photometry, and by matching unresolved sources to FIRST radio catalogs. The automated is sensitive quasars at all redshifts lower than z=5.8. Extended also targeted as low-redshift order investigate evolution of Active Galactic Nuclei (AGN) faint end luminosity function. Nearly 95% previously known recovered (based on...
We present moderate-resolution Keck spectroscopy of quasars at z = 5.82, 5.99, and 6.28, discovered by the Sloan Digital Sky Survey (SDSS). find that Lyα absorption in spectra these evolves strongly with redshift. To ∼ 5.7, as expected from an extrapolation lower redshifts. However, highest-redshift object, SDSSp J103027.10+052455.0 (z 6.28), average transmitted flux is 0.0038 ± 0.0026 times continuum level over 8450 Å < λ 8710 (5.95 zabs 6.16), consistent zero flux. Thus drops a factor...
We determine the number counts and z = 0-5 luminosity function for a well-defined, homogeneous sample of quasars from Sloan Digital Sky Survey (SDSS). conservatively define most uniform statistical possible, consisting 15,343 within an effective area 1622 deg2 that was derived parent 46,420 spectroscopically confirmed broad-line in 5282 imaging data SDSS Data Release 3. The extends i 15 to 19.1 at ≲ 3 20.2 ≳ agree well with results Two Degree Field QSO Redshift (2QZ) redshifts luminosities...
We investigate the extent to which Palomar-Green (PG) Bright Quasar Survey (BQS) is complete and representative of general quasar population by comparing it with imaging spectroscopy from Sloan Digital Sky (SDSS). A comparison SDSS PG photometry both stars quasars reveals need apply a color magnitude recalibration data. Using photometric catalog, we define PG's parent sample objects that are not main-sequence simulate selection this using criteria errors. This simulation shows effective U -...
In the course of its commissioning observations, Sloan Digital Sky Survey (SDSS) has produced one largest redshift samples galaxies selected from CCD images. Using 11,275 complete to r* = 17.6 over 140 deg2, we compute luminosity function in band a range -23 < M -16 (for h 1). The result is well-described by Schechter with parameters ϕ* (1.46 ± 0.12) × 10-2 h3 Mpc-3, M* -20.83 0.03, and α -1.20 0.03. implied density j ≈ (2.6 0.3) 108h L⊙ Mpc-3. We find that surface brightness selection...
We present the power spectrum of reconstructed halo density field derived from a sample luminous red galaxies (LRGs) Sloan Digital Sky Survey (SDSS) Seventh Data Release (DR7). The has direct connection to underlying dark matter for k≤ 0.2 h Mpc−1, well into quasi-linear regime. This enables us use factor ∼8 more modes in cosmological analysis than an with kmax= 0.1 as was adopted SDSS team DR4 LRG sample. observed 0.02 < k Mpc−1 is fitted by our model: χ2= 39.6 40 degrees freedom...
We report the discovery of two well-defined tidal tails emerging from sparse remote globular cluster Palomar 5. These stretch out symmetrically to both sides in direction constant Galactic latitude and subtend an angle 26 on sky. The have been detected commissioning data Sloan Digital Sky Survey, providing deep five-color photometry a 25-wide band along equator. stars make up substantial part (~) current total population magnitude interval 19.5 ≤ i* 22.0. This reveals that is subject heavy...
Abstract We summarize the Sloan Digital Sky Survey data acquisition and processing steps, describe runQA , a pipeline designed for automated quality assessment. In particular, we show how position of stellar locus in color‐color diagrams can be used to estimate accuracy photometric zeropoint calibration better than 0.01 mag 0.03 deg 2 patches. Using this method, that typical errors SDSS imaging are not larger ∼0.01 g r i bands, 0.02 z band, u band (root‐mean‐scatter offsets). (© 2004...
The Sloan Digital Sky Survey-II (SDSS-II) has embarked on a multi-year project to identify and measure light curves for intermediate-redshift (0.05 < z 0.35) Type Ia supernovae (SNe Ia) using repeated five-band (ugriz) imaging over an area of 300 sq. deg. survey region is stripe 2.5° wide centered the celestial equator in Southern Galactic Cap that been imaged numerous times earlier years, enabling construction deep reference image discovery new objects. Supernova observations are being...
We present the fourth edition of Sloan Digital Sky Survey (SDSS) Quasar Catalog. The catalog contains 77,429 objects; this is an increase over 30,000 entries since previous edition. consists objects in SDSS Fifth Data Release that have luminosities larger than Mi = -22.0 (in a cosmology with H0 70 km s-1 Mpc-1, ΩM 0.3, and ΩΛ 0.7), at least one emission line FWHM 1000 or interesting/complex absorption features, are fainter i ≈ 15.0, highly reliable redshifts. area covered by ≈5740 deg2....
We quantify the variability of faint unresolved optical sources using a catalog based on multiple SDSS imaging observations.The covers stripe 82, which lies along celestial equator in southern Galactic hemisphere (22 h 24 m < J2000:0 04 08 , À1:27 þ1:27 $290 deg 2 ), and contains 34 million photometric observations ugriz system for 748,084 at high latitudes (b À20 ) that were observed least four times each ugri bands (with median 10 obtained over $6 yr).In bandpass we compute various...
We introduce a Xilinx RF System-on-Chip (RFSoC)-based qubit controller (called the Quantum Instrumentation Control Kit, or QICK for short), which supports direct synthesis of control pulses with carrier frequencies up to 6 GHz. The can multiple qubits other quantum devices. consists digital board hosting an RFSoC field-programmable gate array, custom firmware, and software optional companion custom-designed analog front-end board. characterize performance system as well its latency,...
The gravity from the quantum entanglement of space-time (GQuEST) experiment uses tabletop-scale Michelson laser interferometers to probe for fluctuations in space-time. We present a practicable interferometer design featuring novel photon-counting readout method that provides unprecedented sensitivity, as it is not subject interferometric standard limit. evaluate potential this measure motivated by recent “geontropic” models. accelerated accrual Fisher information offered enables GQuEST...
We present star count data from the Sloan Digital Sky Survey for 5.8 × 105 stars brighter than g' = 21 mag over 279 deg2 in two samples north and south of Galactic plane. Using these high-latitude (49° < |b| 64°) counts we determine Sun's distance midplane to be 27 ± 4 pc scale height old thin disk 330 3 pc. Because photometric accuracy large area sky coverage data, color-magnitude diagram clearly reveals a significant thick-disk population distinct color halo population. The position...
A sample of 4208 objects with magnitude 15 < g* 22 and colors main-sequence stars have been selected from 370 deg2 Sloan Digital Sky Survey (SDSS) commissioning observations. The data is two long, narrow stripes, each an opening angle greater than 60°, at Galactic latitudes 36° |b| 63° on the celestial equator. Relative photometric calibrations good to 2% consistent absolute photometry allows this uniform be treated statistically over large area. An examination sample's distribution shows...
The photometric calibration of the Sloan Digital Sky Survey (SDSS) is a multi-step process which involves data from three different telescopes: 1.0-m telescope at US Naval Observatory (USNO), Flagstaff Station, Arizona (which was used to establish SDSS standard star network); 0.5-m Photometric Telescope (PT) Apache Point (APO), New Mexico calculates nightly extinctions and calibrates secondary patch transfer fields); 2.5-m APO obtains imaging for proper). In this paper, we describe Monitor...
We describe a standard star catalog constructed using multiple SDSS photometric observations (at least four per band, with median of 10) in the ugriz system. The includes 1.01 million nonvariable unresolved objects from equatorial stripe 82 (|δJ2000.0| < 1.266°) right ascension range 20h34m-4h00m and corresponding r-band (approximately Johnson V-band) magnitudes 14-22. distributions measurements for individual sources demonstrate that pipeline correctly estimates random errors, which are...
We present observations of SDSSp J104433.04-012502.2, a luminous quasar at z = 5.80 discovered from Sloan Digital Sky Survey (SDSS) multicolor imaging data. This object was selected as an i'-band dropout object, with i* 21.8 ± 0.2 and z* 19.2 0.1. It has absolute magnitude M1450 -27.2 (H0 50 km s-1 Mpc-1, q0 0.5). The spectrum shows strong broad Lyα emission line, forest absorption lines mean continuum decrement DA 0.91 Lyman limit system 5.72. also O I Si IV similar to those quasars ≲ 5,...
We present the third edition of Sloan Digital Sky Survey (SDSS) Quasar Catalog. The catalog consists 46,420 objects in SDSS Third Data Release that have luminosities larger than Mi = -22 (in a cosmology with H0 70 km s-1 Mpc-1, ΩM 0.3, and ΩΛ 0.7), at least one emission line FWHM 1000 or are unambiguously broad absorption quasars, fainter i 15.0, highly reliable redshifts. area covered by is ≈4188 deg2. quasar redshifts range from 0.08 to 5.41, median value 1.47; high-redshift sample...
We present an empirical investigation of the colors quasars in Sloan Digital Sky Survey (SDSS) photometric system. The sample studied includes 2625 with SDSS photometry: 1759 found during spectroscopic commissioning and follow-up observations on other telescopes, 50 matches to FIRST quasars, 573 from NASA Extragalactic Database, 243 two or more these sources. are distributed a 25 wide stripe centered celestial equator covering ∼529 deg2. Positions (accurate 02) magnitudes given for 898 known...