Donald G. York
A5018021987- Stellar, planetary, and galactic studies
- Galaxies: Formation, Evolution, Phenomena
- Astronomy and Astrophysical Research
- Astrophysics and Star Formation Studies
- Gamma-ray bursts and supernovae
- Astrophysical Phenomena and Observations
- Astronomical Observations and Instrumentation
- Astro and Planetary Science
- Atmospheric Ozone and Climate
- Astrophysics and Cosmic Phenomena
- Adaptive optics and wavefront sensing
- Cosmology and Gravitation Theories
- Spectroscopy and Laser Applications
- History and Developments in Astronomy
- Scientific Research and Discoveries
- Atomic and Molecular Physics
- Solar and Space Plasma Dynamics
- Radio Astronomy Observations and Technology
- Remote Sensing in Agriculture
- Geophysics and Gravity Measurements
- Molecular Spectroscopy and Structure
- Calibration and Measurement Techniques
- Dark Matter and Cosmic Phenomena
- Laser-induced spectroscopy and plasma
- Spacecraft and Cryogenic Technologies
University of Chicago
2014-2023
Enrico Fermi Center for Study and Research
1997-2023
Fermi National Accelerator Laboratory
2011-2020
University of Illinois Chicago
2018
University of California Davis Medical Center
2017
Apache (Canada)
2010
Dartmouth College
2006
Fuse (United States)
2000
Kitt Peak National Observatory
1989
Princeton University
1974-1983
The Sloan Digital Sky Survey (SDSS) will provide the data to support detailed investigations of distribution luminous and nonluminous matter in universe: a photometrically astrometrically calibrated digital imaging survey π sr above about Galactic latitude 30° five broad optical bands depth g' ∼ 23 mag, spectroscopic approximately 106 brightest galaxies 105 quasars found photometric object catalog produced by survey. This paper summarizes observational parameters products SDSS serves as an...
We measure cosmological parameters using the three-dimensional power spectrum $P(k)$ from over 200 000 galaxies in Sloan Digital Sky Survey (SDSS) combination with Wilkinson Microwave Anisotropy Probe (WMAP) and other data. Our results are consistent a ``vanilla'' flat adiabatic cold dark matter model constant without tilt ${(n}_{s}=1),$ running tilt, tensor modes, or massive neutrinos. Adding SDSS information more than halves WMAP-only error bars on some parameters, tightening...
We present the large-scale correlation function measured from a spectroscopic sample of 46,748 luminous red galaxies Sloan Digital Sky Survey. The survey region covers 0.72 h-3 Gpc3 over 3816 deg2 and 0.16 < z 0.47, making it best yet for study structure. find well-detected peak in at 100 h-1 Mpc separation that is an excellent match to predicted shape location imprint recombination-epoch acoustic oscillations on low-redshift clustering matter. This detection demonstrates linear growth...
We develop a new method to constrain the star formation histories, dust attenuation and stellar masses of galaxies. It is based on two absorption-line indices, 4000-Å break strength Balmer index HδA. Together, these indices allow us mean ages galaxies fractional mass formed in bursts over past few Gyr. A comparison with broad-band photometry then yields estimates mass. generate large library Monte Carlo realizations different including starbursts varying range metallicities. use this median...
We describe the design, construction, and performance of Sloan Digital Sky Survey Telescope located at Apache Point Observatory. The telescope is a modified two-corrector Ritchey-Chretien design which has 2.5-m, f/2.25 primary, 1.08-m secondary, Gascoigne astigmatism corrector, one pair interchangeable highly aspheric correctors near focal plane, for imaging other spectroscopy. final ratio f/5. instrumented by wide-area, multiband CCD camera fiber-fed double spectrographs. Novel features...
We describe the algorithm that selects main sample of galaxies for spectroscopy in Sloan Digital Sky Survey from photometric data obtained by imaging survey. Galaxy properties are measured using Petrosian magnitude system, which measures flux apertures determined shape surface brightness profile. The metric aperture used is essentially independent cosmological dimming, foreground extinction, sky brightness, and galaxy central brightness. consists with r-band r < 17.77 half-light 24.5...
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...
We measure the large-scale real-space power spectrum P(k) using a sample of 205,443 galaxies from Sloan Digital Sky Survey, covering 2417 square degrees with mean redshift z~0.1. employ matrix-based method pseudo-Karhunen-Loeve eigenmodes, producing uncorrelated minimum-variance measurements in 22 k-bands both clustering and its anisotropy due to redshift-space distortions, narrow well-behaved window functions range 0.02 h/Mpc < k 0.3h/Mpc. pay particular attention modeling, quantifying...
We have constructed a large-format mosaic CCD camera for the Sloan Digital Sky Survey. The consists of two arrays, photometric array that uses 30 2048 × SITe/Tektronix CCDs (24 μm pixels) with an effective imaging area 720 cm2 and astrometric 24 400 same pixel size, which will allow us to tie bright standard stars objects imaged in camera. instrument be used carry out photometry essentially simultaneously five color bands spanning range accessible silicon detectors on ground...
We present the 158 standard stars that define u'g'r'i'z' photometric system. These form basis for calibration of Sloan Digital Sky Survey. The defining instrument system and filters, observing process, reduction techniques, software used to create stellar network are all described. briefly discuss history star selection derivation a set transformation equations UBVRCIC system, plans future work.
We study the optical colors of 147,920 galaxies brighter than g* = 21, observed in five bands by Sloan Digital Sky Survey (SDSS) over ∼100 deg2 high Galactic latitude sky along celestial equator. The distribution g*-r* versus u*-g* color-color diagram is strongly bimodal, with an optimal color separator u*-r* 2.22. use visual morphology and spectral classification subsamples 287 500 galaxies, respectively, to show that two peaks correspond roughly early- (E, S0, Sa) late-type (Sb, Sc, Irr)...
We measure the large-scale real-space power spectrum $P(k)$ using luminous red galaxies (LRGs) in Sloan Digital Sky Survey (SDSS) and use this measurement to sharpen constraints on cosmological parameters from Wilkinson Microwave Anisotropy Probe (WMAP). employ a matrix-based estimation method Pseudo-Karhunen-Lo\`eve eigenmodes, producing uncorrelated minimum-variance measurements 20 $k$-bands of both clustering its anisotropy due redshift-space distortions, with narrow well-behaved window...
Abridged: We estimate the distances to ~48 million stars detected by Sloan Digital Sky Survey and map their 3D number density distribution in 100 < D 20 kpc range over 6,500 deg^2 of sky. The data show strong evidence for a Galaxy consisting an oblate halo, disk component, localized overdensities with exponential parameters (bias-corrected assumed 35% binary fraction) H_1 = 300 pc, L_1 2600 H_2 900 L_2 3600 local normalization 12%. find halo be oblate, best-fit axis ratio c/a 0.64, r^{-2.8}...
We present an analysis of the mid-infrared (MIR) and optical properties type 1 (broad-line) quasars detected by Spitzer Space Telescope. The MIR color-redshift relation is characterized to z ~ 3, with predictions = 7. demonstrate how combining colors can yield even more efficient selection active galactic nuclei (AGNs) than or alone. Composite spectral energy distributions (SEDs) are constructed for 259 both Sloan Digital Sky Survey photometry, supplemented near-IR, GALEX, VLA, ROSAT data,...
We present the design and performance of multi-object fiber spectrographs for Sloan Digital Sky Survey (SDSS) their upgrade Baryon Oscillation Spectroscopic (BOSS). Originally commissioned in Fall 1999 on 2.5-m aperture Telescope at Apache Point Observatory, produced more than 1.5 million spectra SDSS SDSS-II surveys, enabling a wide variety Galactic extra-galactic science including first observation baryon acoustic oscillations 2005. The were upgraded 2009 are currently use BOSS, flagship...
We combine the constraints from recent Ly$\ensuremath{\alpha}$ forest analysis of Sloan Digital Sky Survey (SDSS) and SDSS galaxy bias with previous clustering, latest supernovae, 1st year WMAP cosmic microwave background anisotropies. find significant improvements on all cosmological parameters compared to constraints, which highlights importance combining other probes. Combining we for primordial slope ${n}_{s}=0.98\ifmmode\pm\else\textpm\fi{}0.02$. see no evidence running,...
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 the fifth edition of Sloan Digital Sky Survey (SDSS) Quasar Catalog, which is based upon SDSS Seventh Data Release. The catalog, contains 105,783 spectroscopically confirmed quasars, represents conclusion SDSS-I and SDSS-II quasar survey. catalog consists objects that have luminosities larger than M_i = -22.0 (in a cosmology with H_0 70 km/s/Mpc Omega_M 0.3, Omega_Lambda 0.7) at least one emission line FWHM 1000 km/s or interesting/complex absorption features, are fainter i > 15.0...
We present the results from a survey of i-dropout objects selected ∼1550 deg2 multicolor imaging data Sloan Digital Sky Survey to search for luminous quasars at z ≳ 5.8. Objects with i*-z* > 2.2 and z* < 20.2 are selected, follow-up J-band photometry is used separate L- T-type cool dwarfs high-redshift quasars. describe discovery three new quasars, SDSSp J083643.85+005453.3 (z = 5.82), J130608.26+035626.3 5.99), J103027.10+052455.0 6.28). The quasar radio source flux 1.1 mJy 20 cm. spectra...
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 study the luminosity and color dependence of galaxy two-point correlation function in Sloan Digital Sky Survey, starting from a sample ~200,000 galaxies over 2500 deg2. concentrate our analysis on volume-limited subsamples specified ranges, for which we measure projected wp(rp), is directly related to real-space ξ(r). The amplitude wp(rp) rises continuously with Mr ≈ -17.5 -22.5, most rapid increase occurring above characteristic L* (Mr -20.5). Over scales 0.1 h-1 Mpc < rp 10 Mpc,...
We present in this paper a detailed analysis of the effect environment on star formation activity galaxies within Early Data Release (EDR) Sloan Digital Sky Survey (SDSS). have used Hα emission line to derive rate (SFR) for each galaxy volume-limited sample 8598 with 0.05 ≤ z 0.095 and M(r*) -20.45. find that SFR is strongly correlated local (projected) density, thus we here density-SFR relation analogous density-morphology relation. The density seen three ways. First, overall distribution...