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Cyberinfrastructure for Astronomy. Roy Williams US National Virtual Observatory Project California Institute of Technology. Toward a “new astronomy”. Past: Observations of small, carefully selected samples. Trends. Future dominated by detector improvements.
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Cyberinfrastructurefor Astronomy Roy Williams US National Virtual Observatory Project California Institute of Technology
Toward a “new astronomy” • Past: Observations of small, carefully selected samples
Trends • Future dominated by detector improvements • Moore’s Law growth in CCD capabilities • Gigapixel arrays on the horizon • New Detector Technologies (e.g., STJ) • Improvements in computing and storage will track growth in data volume • Investment in software is critical, and growing Total area of 3m+ telescopes in the world in m2, total number of CCD pixels in Megapixels, as a function of time. Growth over 25 years is a factor of 30 in glass, 3000 in pixels.
New Astronomy: Data Mining • Future: Multi-wavelength data for millions of objects, allowing us to: • Discover significant patterns from the analysis of statistically rich and unbiased image/catalog databases • Understand complex astrophysical systems via confrontation between data and sophisticated numerical simulation
New Astronomy: New Views • Simultaneous access to • multi-wavelength archives, • advanced visualization and • statistical analysis tools
New Astronomy: Multispectral Imagery Crab Nebula.3 channels: X-ray in blue, optical in green, and radio in red. Moffet Field California. 224 channels from 400 nm to 2500 nm
The Virtual Observatory US VO http://us-vo.org International VO http://ivoa.net
Interoperability VizieR: Contains more than 4000 astronomical catalogues consisting of one or several tables. “Give me all tables containing the V magnitude in the Johnson system.” 144 different names for Johnson V.
Science applications • Resource discovery: Registry • Data discovery and integration: DataScope • Database queries and cross-correlation: OpenSkyQuery • Spectrum browsing and analysis: Spectrum Services • Source extraction / cross-correlation: WESEX, WCS fixer • Sky coverage of catalogs: Catalog Coverage Maps • On-demand mosaicking: Mosaic Service
NVO Registry Portal Find source catalogs, image archives, and other astronomical resources registered with the NVO A Registry is a distributed database of Virtual Observatory resources: primarily access services for catalog, image, and spectral data, but also descriptions of organizations and data collections. There are several coordinated registry implementations that share information by harvesting each other's resources. This registry is at STScI in Baltimore, MD. Searches for resources can be done by keyword, or advanced queries can be expressed in the SQL language. The registry is open for humans through web forms, or machines through SOAP web services.
DataScope Discover and explore data in the Virtual Observatory Using the NVO DataScope scientists can discover and explore hundreds of data resources available in the Virtual Observatory. DataScope uses the VO registry and VO access protocols to link to archives and catalogs around the world. Users can immediately discover what is known about a given region of the sky: they can view survey images from the radio through the X-ray, explore archived observations from multiple archives, find recent articles describing analysis of data in the region, find known interesting or peculiar objects and survey datasets that cover the region. A summary page provides a quick précis of all of the available data. Users can download images and tables for further analysis on their local machines, or they can go directly to a growing set of VO enabled analysis tools, including Aladin, OASIS, VOPlot and VOStat.
DataScope with VOEvent See archival images corresponding to the latest gamma-ray bursts The “view-data” link goes directly to DataScope. See the event context from all major surveys. The results have already been collected from across the VO as soon as the GRB happens.
OpenSkyQuery Cross-match your data with numerous catalogs OpenSkyQuery allows you to cross-match astronomical catalogs and select subsets of catalogs with a general and powerful query language. You can also import a personal catalog of objects and cross-match it against selected databases.
Spectrum Services Search, plot, and retrieve SDSS, 2dF, and other spectra The Spectrum Services web site is dedicated to spectrum related VO services. On this site you will find tools and tutorials on how to access close to 500,000 spectra from the Sloan Digital Sky Survey (SDSS DR1) and the 2 degree Field redshift survey (2dFGRS). The services are open to everyone to publish their own spectra in the same framework. Reading the tutorials on XML Web Services, you can learn how to integrate the 45 GB spectrum and passband database with your programs with few lines of code.
Web Enabled Source Identification with Cross-Matching (WESIX) Upload images to SExtractor and cross-correlate the objects found with selected survey catalogs. This NVO service does source extraction and cross-matching for any astrometric FITS image. The user uploads a FITS image, and the remote service runs the SExtractor software for source extraction. The resulting catalog can be cross-matched with any of several major surveys, and the results returned as a VOTable. The web page also allows use of Aladin or VOPlot to visualize results.
WCS Fixer Refine an image with approximate pixel mapping to the exact WCS solution An essential part of an astronomical image is the mapping between pixels and sky — the so-called WCS information. This NVO service takes an image with approximate WCS and computes the exact WCS, using major catalogs such as USNO-B and SDSS. • Source detect • Match to catalog • Fit parameters Input image USNO-B1 USNO-A2 SDSS NOMAD Exact WCS Client Remote NVO Service
Catalog Coverag Maps Find catalogs and source density for the position or object name of interest An all-sky map showing distribution of sources across the sky. Dynamically generate a custom map for specific region and selection of catalogs. Composite all-sky overlay maps show which regions are covered by all of the selected catalogs. Catalogue of Stellar Spectral Classifications (Skiff, 2005)
Try it out! • Start at http://us-vo.org • Develop your own VO-enabled software with the NVO Summer School software kit • For developers: come to the 2006 NVO Summer School in Aspen
Services Registry Views
Portals, Applications, Interfaces Spectrum Datacube Source Catalog Image Region Education Event Spectral Lines Characterization FITS Space/Time VOTable Semantics MIME type File/Blob XML Table Services, Filesystems, VOSpace View: Client’s Frame of Reference
Service Requests Custom .... Image Spectrum Catalog Datacube Registry Cone VOSpace Query Language Contracts (WSDL) Async Certificates Accounts & Security Grid& Globus Protocols (SOAP, REST, GET) WWW Files and Databases Service: Interacting with remote resources internet
Example Web Service • Web Services • Remote execution • Structures in and out • Self-defined (WSDL) • Click or code Client interface name= M51 x= 10 y= 10 sky_survey=DSS2_red mime_type=download_gif Service endpoint http://archive.eso.org/dss/dss/image Request: Keyword/value Response: image/gif
Mosaicking enginefrom services NVO Registry Logical SIAP Trust Request:survey,region, [login] Portal Physical SIAP web access Image Data Service Sandbox Computing
Image Spectrum Skynode RegistryofRegistries Cone Custom .... Etc etc .... Organization Provenance Compute Service Event publisher Application Service Registry Curation IVO identifiers Harvest Registry: Publish, Find & Use
Distributed Registry Astrogrid CfA NCSA CDS ESO STScI/JHU NOAO Caltech HEASARC JapanVO Ongoing harvesting May 05
Registry OAI Query Registry Registry OAI OAI Publish Publish DataScope • Federates multiple cone, SIAP services JHU/StSci NCSA 4 Caltech Goddard DataScope 2 1 3
Palomar-Quest SurveyDjorgovski, Baltey, Drake, Graham, Mahabal, Williams Transient pipeline computing reservation at sunrise for immediate followup of transients Synoptic survey massive resampling for ultrafaint detection of hi-Z quasars P48 Telescope 50 Gbyte/night ALERT Yale Caltech NCSA NCSA and Caltech and Yale run different pipelines on the same data
Griffith Observatory“big picture” 158 feet 158 feet 158 feet Show tile b14
VOEvent Instant Messaging for Astronomy Automated architecture Structured packets Trust 1604 image of Cas A
Transient Sources in the Sky • Asteroids • Variables and binaries • Supernova • Gamma-ray burst • Lensing events • Gravitational waves • etc etc and: • NOT YET THOUGHT OF ....? • http://voeventnet.caltech.edu/transients/
Gamma-ray Burst Satellite Feed author/publisher telephone email socket subscriber subscriber subscriber Single provider Structured, for machine understanding Fixed structures Standard transports
OGLE III Poland GCN NASA/GSFC Liverpool Telescope La Palma SDSS SNe U Washington/Stanford Faulkes Hawaii/Australia Exeter, UK Palomar-Quest Caltech Caltech Los Alamos Microlensing Survey Exeter UKIRT Hawaii Tucson Palomar P60 Caltech Author Publisher Repository Relay Subscriber Raptor LANL Pairitel Berkeley CTIO/KPNO surveys
Sources of Events • GCN, (Swift, Integral, etc) • Palomar-Quest (Caltech), Raptor (LANL), etc • Supernova factories • Variable star observers (AAVSO) • non-photon: • LIGO, neutrinos, cosmic rays, etc • Future • PannStarrs, LSST
VOEvent Structure • Who • Publisher, Contact, etc • Subscribers will use PublisherID to select • WhereWhen (== STC) • Can be simple eg RA, Dec, eg UTC • Can be sophisticated, eg multiple frames, near objects, etc • What • Hierarchy of named parameters • Units, Semantic type (UCD) • References, Descriptions • How • How was the evidence gathered: camera, telescope, etc • Why • probability list of interpretation • supernova, comet, asteroid, ..... • Citation • Link to other VOEvent: Followup, Supercede, Retraction, • Link to support data
Google-like interfaces (coming) • Prototype pan/zoom at Pittsburgh