G. R. Knapp
A5083606927- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Astrophysics and Star Formation Studies
- Galaxies: Formation, Evolution, Phenomena
- Gamma-ray bursts and supernovae
- Astro and Planetary Science
- Astronomical Observations and Instrumentation
- Astrophysical Phenomena and Observations
- Spectroscopy and Laser Applications
- Adaptive optics and wavefront sensing
- Atmospheric Ozone and Climate
- Analytical chemistry methods development
- Molecular Spectroscopy and Structure
- History and Developments in Astronomy
- Astrophysics and Cosmic Phenomena
- Scientific Research and Discoveries
- Radio Astronomy Observations and Technology
- Solar and Space Plasma Dynamics
- Atomic and Molecular Physics
- Geophysics and Gravity Measurements
- Remote Sensing in Agriculture
- Electrochemical Analysis and Applications
- Space Exploration and Technology
- Cosmology and Gravitation Theories
- Mass Spectrometry Techniques and Applications
Princeton University
2013-2022
AlbaNova
2016
Stockholm University
2016
Graz University of Technology
1992-2011
University of Washington
2001-2009
Leibniz Institute for Astrophysics Potsdam
2009
Tokyo Institute of Technology
2009
Max Planck Institute for Astronomy
2009
Japan Aerospace Exploration Agency
2009
Institute of Space and Astronautical Science
2009
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...
This paper describes the Seventh Data Release of Sloan Digital Sky Survey (SDSS), marking completion original goals SDSS and end phase known as SDSS-II. It includes 11,663 deg2 imaging data, with most ∼2000 increment over previous data release lying in regions low Galactic latitude. The catalog contains five-band photometry for 357 million distinct objects. survey also repeat on a 120° long, 25 wide stripe along celestial equator Southern Cap, some covered by many 90 individual runs. We...
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 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...
Building on the legacy of Sloan Digital Sky Survey (SDSS-I and II), SDSS-III is a program four spectroscopic surveys three scientific themes: dark energy cosmological parameters, history structure Milky Way, population giant planets around other stars. In keeping with SDSS tradition, will provide regular public releases all its data, beginning Data Release 8 (DR8), which was made in 2011 January includes SDSS-I SDSS-II images spectra reprocessed latest pipelines calibrations produced for...
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 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)...
ABSTRACT The Sloan Digital Sky Survey III (SDSS-III) presents the first spectroscopic data from Baryon Oscillation Spectroscopic (BOSS). This ninth release (DR9) of SDSS project includes 535,995 new galaxy spectra (median z ∼ 0.52), 102,100 quasar 2.32), and 90,897 stellar spectra, along with presented in previous releases. These were obtained BOSS spectrograph taken between 2009 December 2011 July. In addition, parameters pipeline, which determines radial velocities, surface temperatures,...
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...
The Sloan Digital Sky Survey (SDSS) started a new phase in August 2008, with instrumentation and surveys focused on Galactic structure chemical evolution, measurements of the baryon oscillation feature clustering galaxies quasar Ly alpha forest, radial velocity search for planets around ~8000 stars. This paper describes first data release SDSS-III (and eighth counting from beginning SDSS). includes five-band imaging roughly 5200 deg^2 Southern Cap, bringing total footprint SDSS to 14,555...
We study the evolution of ionization state IGM at end reionization epoch using spectra a sample nineteen quasars 5.745.7: optical depth changes from tau ~ (1+z)^{4.3} to (1+z)^{>11}, and average length dark gaps with tau>3.5 increases <10 >80 comoving Mpc. The dispersion properties along different lines sight also rapidly, implying fluctuations by factor >4 in UV background z>6, when mean free path photons is comparable correlation galaxies. shows most dramatic increase...
This paper describes the Sixth Data Release of Sloan Digital Sky Survey. With this data release, imaging northern Galactic cap is now complete. The survey contains images and parameters roughly 287 million objects over 9583 deg2, including scans a large range latitudes longitudes. also includes 1.27 spectra stars, galaxies, quasars, blank sky (for subtraction) selected 7425 deg2. release much more stellar spectroscopy than was available in previous releases detailed estimates temperatures,...
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}...
Here we present the New York University Value-Added Galaxy Catalog (NYU-VAGC), a catalog of local galaxies (mostly below redshift about 0.3) based on set publicly-released surveys (including 2dFGRS, 2MASS, PSCz, FIRST, and RC3) matched to Sloan Digital Sky Survey (SDSS) Data Release 2. Excluding areas masked by bright stars, photometric sample covers 3514 square degrees spectroscopic 2627 (with 85% completeness). Earlier, proprietary versions this have formed basis many SDSS investigations...
The Sloan Digital Sky Survey (SDSS) has validated and made publicly available its Second Data Release. This data release consists of 3324 deg2 five-band (ugriz) imaging with photometry for over 88 million unique objects, 367,360 spectra galaxies, quasars, stars, calibrating blank sky patches selected 2627 this area, tables measured parameters from these data. reach a depth r ≈ 22.2 (95% completeness limit point sources) are photometrically astrometrically calibrated to 2% rms 100 mas per...
This paper describes the Fourth Data Release of Sloan Digital Sky Survey (SDSS), including all survey-quality data taken through 2004 June. The release includes five-band photometric for 180 million objects selected over 6670 deg2 and 673,280 spectra galaxies, quasars, stars from 4783 those imaging using standard SDSS target selection algorithms. These numbers represent a roughly 27% increment Third Release; previous releases are included in present release. also an additional 131,840...
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...
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 target selection and resulting properties of a spectroscopic sample luminous red galaxies (LRGs) from imaging data Sloan Digital Sky Survey (SDSS). These are selected on basis color magnitude to yield intrinsically that extends fainter farther than main flux-limited portion SDSS galaxy sample. The is designed impose passively evolving luminosity rest-frame cut redshift 0.38. Additional, yet more included ∼0.5. Approximately 12 these per square degree targeted for...
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...