The HEASARC's VO capabilties are part of the broader NASA VO framework. The HEASARC is a member of the NASA Astronomical Virtual Observatories (NAVO) where we work with other NASA archives to ensure comprehensive and consistent VO access to NASA mission datasets.

The Virtual Astronomical Observatory has adopted standards to facilitate the dissemination of astronomical data. Data can now be acquired using protocols which allow users to retrieve data in VOTable formatted xml files. This system provides an alternative to data extraction via conventional astronomical catalog interfaces. The HEASARC supports these VO standards and is a major player in the national and international VO community. Users may now query the HEASARC's catalogs using VO-enabled services and specialized tools. This page describes how to get to the HEASARC VO-enabled services and provides information on other HEASARC VO activities.

HEASARC VO-enabled Data Services

Getting HEASARC Catalogs in VOTable format

All HEASARC Browse Catalogs are available as formatted VOTable documents. Use http://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/getvotable.pl?name=xxx as the base URL where "xxx" is the table/catalog name.

The VOTable format can also be chosen in the HEASARC's Browse system. VOTables can be read and manipulated by powerful utilities like TOPCAT and VOPlot.

Getting HEASARC Catalogs Using the Cone Search Protocol

All HEASARC Browse Catalogs are available through the Cone search protocol. The result of a search is a table that contains metadata on a source. Use "http://heasarc.gsfc.nasa.gov/cgi-bin/vo/cone/coneGet.pl?table=xxx" as the base URL where "xxx" is the short name of the table/catalog (more info).

Getting SkyView Surveys Using SIAP

All SkyView surveys can be accessed through the Simple Image Access Protocol (SIAP). Use the base URL "http://skyview.gsfc.nasa.gov/cgi-bin/vo/sia.pl?survey=xxx" where "xxx" is a string or substring present in the survey name (more info).

Getting HEASARC Data Sets Using the Simple Spectral Access Protocol

A number of data sets are available through the SSA protocol. Use "https://heasarc.gsfc.nasa.gov/xamin/vo/ssa?table=xxx" as the base URL where "xxx" is the short name of the table/catalog (more info).

Getting HEASARC Table Data Using the Table Access Protocol

HEASARC general table data may be accessed through the TAP protocol. Use "https://heasarc.gsfc.nasa.gov/xamin/vo/tap/" as the base URL (more info).

Finding HEASARC VO Services

The HEASARC publishes information about its services in the NAVO Directory. You can also search the ESAVO registry for HEASARC services.

VO Operations Services

VO Validation Service

The VO Validation Service checks that VO services are in compliance with VO standards. The VO Validation Service home page summarizes the results of these checks and allows users to view the validation status of individual services at their site.

Monitoring Services

The VO Monitor displays the status of VO sites and services and allows users to test services interactively.

The VO Statistics Service displays uptime statistics for VO sites in a given range of start and end dates.

Historical References

NVO Book

This volume is a collection of the NVO Summer School lectures and tutorials. It includes a complete set of software libraries and worked examples to guide the astronomer/software developer through the process of developing VO-enabled programs in a variety of programming languages and scripting environments.