Introduction: The Virtual Observatory and Astronomical Data Robert Hanisch Space Telescope Science Institute Baltimore, Maryland USA Project Manager, US National Virtual Observatory T HE US N ATIONAL V IRTUAL O BSERVATORY

3 Sept 2008NVO Summer School - Santa Fe2 NASA astronomy data centers Data from NASA space missions is archived and maintained by a network of wavelength-oriented data centers –Optical/UV/Near-IR: Multimission Archive at Space Telescope (MAST) –X-ray/gamma ray: High Energy Astrophysics Science Archive Research Center (HEASARC) –IR: Infrared Science Archive (IRSA, Caltech) –Microwave background: Legacy Archive for Microwave Background Data Analysis (LAMBDA)

3 Sept 2008NVO Summer School - Santa Fe3 NASA active missions Active NASA missions provide direct data services –Hubble Space Telescope, STScI, integrated with MAST –Hubble Legacy Archive –Chandra X-ray Center –GLAST (Gamma-ray Large Area Space Telescope)

3 Sept 2008NVO Summer School - Santa Fe4 Astronomical data services Bibliographic and value-added services –Astrophysics Data System (ADS) –NASA/IPAC Extragalactic Database (NED) –Centre de Données astronomiques de Strasbourg (CDS)

3 Sept 2008NVO Summer School - Santa Fe5 Ground-based observatories National Optical Astronomy Observatory National Radio Astronomy Observatory National Astronomy and Ionosphere Center (Arecibo)

3 Sept 2008NVO Summer School - Santa Fe6 Surveys Sloan Digital Sky Survey (SDSS) Guide Star Catalog and Digitized Sky Survey (GSC and DSS, in MAST) 2 Micron All Sky Survey (2MASS, at IRSA)

3 Sept 2008NVO Summer School - Santa Fe7 This is great, but… Many data collections, many web sites, many interfaces to learn The way data is delivered can be different from site to site Enter… the Virtual Observatory

3 Sept 2008NVO Summer School - Santa Fe8 Without VO astronomer archive 1 survey 2 survey 1 archive 2 service 1 archive 3 service 2 survey 3 service 3 n services, n interfaces

3 Sept 2008NVO Summer School - Santa Fe9 With VO astronomer archive 1 survey 2 survey 1 archive 2 service 1 archive 3 service 2 survey 3 service 3 n services, 1 interface VO

3 Sept 2008NVO Summer School - Santa Fe10 What is [a,the] Virtual Observatory? A suite of software applications on a set of computers that allows users to uniformly find, access, and use resources (data, software, document, and image products and services using these) from a collection of distributed product and service providers. [B. Weigel, GMU; ViRBO] A distributed, scalable education and research environment for searching, integrating, and analyzing observational, experimental, and model databases. [P. Fox, NCAR; VSTO] A collection of integrated astronomical data archives and software tools that utilize computer networks to create an environment in which research can be conducted. [answers.com]

3 Sept 2008NVO Summer School - Santa Fe11 What is [a,the] Virtual Observatory? Distributed Networkedvirtual organizations Collaborative Uniform interfaces Standards-based Scalable Democratizing Supporting innovation and efficiency in research

3 Sept 2008NVO Summer School - Santa Fe12 Toward a new astronomy Past: Observations of small, carefully selected samples (often with a priori prejudices) of objects in one or a few wavelength bands

3 Sept 2008NVO Summer School - Santa Fe13 Toward a new astronomy 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

3 Sept 2008NVO Summer School - Santa Fe14 Toward a new astronomy Discovering new phenomena and patterns in these datasets will require simultaneous access to multi-wavelength archives, advanced visualization and statistical analysis tools

3 Sept 2008NVO Summer School - Santa Fe15 Threads of the the VO Fabric Multiwavelength astrophysics Archival Research Survey astronomy Temporal astronomy NGC3104 Moores LawDigital detectorsThe InternetData Standards

3 Sept 2008NVO Summer School - Santa Fe16 Show me…

3 Sept 2008NVO Summer School - Santa Fe17 Table Viewer Registry Inventory Collector Integrator Command Line Command Line Table Translator Table Translator Help More Tools Data Discovery Portal (concept)

3 Sept 2008NVO Summer School - Santa Fe18 Registry

3 Sept 2008NVO Summer School - Santa Fe19 Registry

3 Sept 2008NVO Summer School - Santa Fe20 Registry

3 Sept 2008NVO Summer School - Santa Fe21 Simple Search

3 Sept 2008NVO Summer School - Santa Fe22 Table Viewer

3 Sept 2008NVO Summer School - Santa Fe23 Table Viewer ASCII File XML File VIM Service Inventory Service

3 Sept 2008NVO Summer School - Santa Fe24 Table Viewer

3 Sept 2008NVO Summer School - Santa Fe25 Inventory Service.

3 Sept 2008NVO Summer School - Santa Fe26 Inventory Service

3 Sept 2008NVO Summer School - Santa Fe27 Back to Table Viewer

3 Sept 2008NVO Summer School - Santa Fe28 Integrator

3 Sept 2008NVO Summer School - Santa Fe29 Integrator

3 Sept 2008NVO Summer School - Santa Fe30 Collector

3 Sept 2008NVO Summer School - Santa Fe31 Collector

3 Sept 2008NVO Summer School - Santa Fe32 Collector

3 Sept 2008NVO Summer School - Santa Fe33 Collector

3 Sept 2008NVO Summer School - Santa Fe34 Collector Aladin

3 Sept 2008NVO Summer School - Santa Fe35 Command Line

3 Sept 2008NVO Summer School - Santa Fe36 Open SkyQuery 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.

3 Sept 2008NVO Summer School - Santa Fe37 Open SkyQuery

3 Sept 2008NVO Summer School - Santa Fe38

3 Sept 2008NVO Summer School - Santa Fe39

3 Sept 2008NVO Summer School - Santa Fe40 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.

3 Sept 2008NVO Summer School - Santa Fe41 NVO: Spectrum Services

3 Sept 2008NVO Summer School - Santa Fe42 NVO: Spectrum Services Bandpass Functions

3 Sept 2008NVO Summer School - Santa Fe43 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.

3 Sept 2008NVO Summer School - Santa Fe44 Coverage Maps The NVO Sky Statistics Service generates source counts, coverage maps, and links to downloadable data for catalog holdings available through the NVO protocols, including IRSA, NED and CDS VizieR View catalog coverage maps and source inventories for a position or object of interest.

3 Sept 2008NVO Summer School - Santa Fe45 WCS Fixer Repair image coordinates in images with inaccurate or misaligned coordinate systems.

3 Sept 2008NVO Summer School - Santa Fe46 VOEvent Net Explore the multiwavelength sky in the vicinity of transient events.

3 Sept 2008NVO Summer School - Santa Fe47 Montage Mosaics Make mosaics from 2MASS, DPOSS, or SDSS images.

3 Sept 2008NVO Summer School - Santa Fe48 VO Tools VOTable display and analysis –VOPlot, Topcat, Mirage Image display and analysis –Aladin, OASIS –Other standard display tools for downloaded data Spectrum display and analysis –VOSpec, SpecView

3 Sept 2008NVO Summer School - Santa Fe49 Summary The VO provides new ways to discover, access, and analyze data from astronomical data collections worldwide All major data centers provide VO-compatible interfaces to their data We hope you will become familiar with the capabilities of the VO through this Summer School, and that it will make your astronomical research efforts more efficient and effective