Peter Kunszt
A5049456288- Distributed and Parallel Computing Systems
- Advanced Data Storage Technologies
- Scientific Computing and Data Management
- Galaxies: Formation, Evolution, Phenomena
- Advanced Database Systems and Queries
- Astronomy and Astrophysical Research
- Gamma-ray bursts and supernovae
- Data Management and Algorithms
- Parallel Computing and Optimization Techniques
- Stellar, planetary, and galactic studies
- Astronomical Observations and Instrumentation
- Algorithms and Data Compression
- Peer-to-Peer Network Technologies
- Cloud Computing and Resource Management
- Bioinformatics and Genomic Networks
- Remote Sensing in Agriculture
- Service-Oriented Architecture and Web Services
- Astrophysical Phenomena and Observations
- Computational Physics and Python Applications
- Geographic Information Systems Studies
- CRISPR and Genetic Engineering
- Advanced Computational Techniques and Applications
- Cosmology and Gravitation Theories
- Environmental Monitoring and Data Management
- Advanced Proteomics Techniques and Applications
SystemsX.ch
2011-2014
ETH Zurich
2011-2014
SIB Swiss Institute of Bioinformatics
2014
University of Zurich
2014
Swisscom (Switzerland)
2006-2010
CSCS - Swiss National Supercomputing Centre
2006-2010
European Organization for Nuclear Research
2001-2007
Organizzazione Sociopsichiatrica Cantonale
2006
Johns Hopkins University
2000-2006
Carnegie Mellon University
2002
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...
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...
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 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)...
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...
The Sloan Digital Sky Survey has validated and made publicly available its First Data Release. This consists of 2099 square degrees five-band (u, g, r, i, z) imaging data, 186,240 spectra galaxies, quasars, stars calibrating blank sky patches selected over 1360 this area, tables measured parameters from these data. data go to a depth r ~ 22.6 are photometrically astrometrically calibrated 2% rms 100 milli-arcsec per coordinate, respectively. cover the range 3800--9200 A, with resolution...
We present the first measurements of clustering in Sloan Digital Sky Survey (SDSS) galaxy redshift survey. Our sample consists 29,300 galaxies with redshifts 5,700 km/s < cz 39,000 km/s, distributed several long but narrow (2.5-5 degree) segments, covering 690 square degrees. For full, flux-limited sample, redshift-space correlation length is approximately 8 Mpc/h. The two-dimensional function ξ(r_p,π) shows clear signatures both small-scale, ``fingers-of-God'' distortion caused by...
In wide area computing systems, it is often desirable to create remote read-only copies (replicas) of files. Replication can be used reduce access latency, improve data locality, and/or increase robustness, scalability and performance for distributed applications. We define a replica location service (RLS) as system that maintains provides information about the physical locations copies. An RLS typically functions one component grid architecture. This paper makes following contributions....
The past few years have seen the creation of first production level Grid infrastructures that offer their users a dependable service at an unprecedented scale.Depending on flavor middleware services these deploy (for instance Condor, gLite, Globus, UNICORE, to name only few) different interfaces program are provided.Despite ongoing efforts standardize interfaces, there still significant differences in how applications can interface infrastructure.In this paper we describe (gLite) and...
This is the fourth paper in a series aimed at finding high-redshift quasars from five-color imaging data taken along Celestial Equator by SDSS. during its commissioning phase. In this paper, we use color-selected sample of 39 luminous presented Paper III to derive evolution quasar luminosity function over range 3.6
The Sloan Digital Sky Survey has confirmed the existence of populations broad absorption line (BAL) quasars with various unusual properties. We present and discuss twenty-three such objects consider implications their wide range properties for models BAL outflows in general. have discovered one quasar a record number lines. Two other similarly complex many narrow troughs show MgII extending longward systemic host galaxy redshifts. This can be explained as an extended continuum source by...
We investigate the photometric properties of 456 bright galaxies using imaging data recorded during commissioning phase Sloan Digital Sky Survey (SDSS). Morphological classification is carried out by correlating results several human classifiers. Our purpose to examine statistical color indices, scale lengths, and concentration indices as functions morphology for SDSS system. find that u'-g', g'-r', r'-i' colors match well with those expected from synthetic calculation spectroscopic energy...
We present bright galaxy number counts in five broad bands (u', g', r', i', z') from imaging data taken during the commissioning phase of Sloan Digital Sky Survey (SDSS). The are derived two independent stripes scans along celestial equator, one each toward northern and southern Galactic cap, covering about 230 210 deg2, respectively. A careful study is made to verify reliability photometric catalog. For galaxies brighter than r* = 16, catalog produced by automated software examined against...
In wide area computing systems, it is often desirable to create remote read-only copies (replicas) of files. Replication can be used reduce access latency, improve data locality, and/or increase robustness, scalability and performance for distributed applications. We define a replica location service (RLS) as system that maintains provides information about the physical locations copies. An RLS typically functions one component grid architecture. This paper makes following contributions....
The next-generation astronomy digital archives will cover most of the sky at fine resolution in many wavelengths, from X-rays, through ultraviolet, optical, and infrared. be stored diverse geographical locations. One first these projects, Sloan Digital Sky Survey (SDSS) is creating a 5-wavelength catalog over 10,000 square degrees (see http://www.sdss.org/). 200 million objects multi-terabyte database have mostly numerical attributes 100+ dimensional space. Points this space highly...
The SkyServer provides Internet access to the public Sloan Digital Sky Survey (SDSS) data for both astronomers and science education. This paper describes goals architecture. It also our experience operating on Internet. SDSS is well-documented so it makes a good test platform research database algorithms performance.
Early photometric data from the Sloan Digital Sky Survey (SDSS) contain angular positions for 1.5 million galaxies. In companion papers, correlation function $w(\theta)$ and 2D power spectrum $C_l$ of these galaxies are presented. Here we invert Limber's equation to extract 3D results. We accomplish this using an estimate $dn/dz$, redshift distribution in four different magnitude slices SDSS catalog. The resulting estimates agree with each other previous over a range wavenumbers $0.03 <...
We describe a method to subdivide the surface of sphere into spherical triangles similar, but not identical, shapes and sizes. The Hierarchical Triangular Mesh (HTM) is quad-tree that particularly good at supporting searches different resolutions, from arc seconds hemispheres. subdivision scheme universal, providing basis for addressing fast lookups. HTM provides an efficient geospatial indexing in relational databases where data have inherent location on either celestial or Earth. index...
The Sloan Digital Sky Survey is one of the first multicolor photometric and spectroscopic surveys designed to measure statistical properties galaxies within local Universe. In this Letter we present some initial results on angular 2-point correlation function measured from early SDSS galaxy data. form function, over magnitude interval 18
We present results on over 100 high-redshift quasars found in the Sloan Digital Sky Survey (SDSS), using automated selection algorithms applied to SDSS imaging data and with spectroscopic confirmation obtained during routine operations of 2.5-m telescope. The spectra cover wavelength range 3900--9200 Angstroms at a spectral resolution 1800, have been for 116 redshifts greater than 3.94; 92 these objects were previously uncataloged, significantly increasing current tally published z>4...
We demonstrate that the design of Sloan Digital Sky Survey (SDSS) filter system and quality SDSS imaging data are sufficient for determining accurate precise photometric redshifts quasars. Using a sample 2625 quasars, we show "photo-z" determination is even possible z ≤ 2.2 despite lack strong continuum break, which robust photo-z techniques normally require. find that, using our empirical method on objects known to be approximately 70% correct within Δz = 0.2; fraction better > 3. The...
An earlier paper (Szalay et. al. "Designing and Mining MultiTerabyte Astronomy Archives: The Sloan Digital Sky Survey," ACM SIGMOD 2000) described the Survey's (SDSS) data management needs by defining twenty database queries twelve visualization tasks that a good system should support. We built interfaces to support both query load also website for ad-hoc access. This reports on design, describes loading pipeline, implementation performance. typically translated single SQL statement. Most...