Two powerful and currently active X-ray missions, NASA's Chandra X-Ray Observatory (Chandra) and ESA's X-Ray Multi-Mirror (XMM) Newton, are performing some of the deepest and widest serendipitous X-ray surveys ever undertaken. These surveys can represent large expenditures of astronomical resources. The scientific aims of extragalactic surveys are unique, as are the observational and theoretical challenges they present. Multiwavelength followup of serendipitously detected X-ray sources is crucial to understand the properties of the objects observed, resulting in large imaging campaigns from radio frequencies to gamma-rays for specific areas of the sky. Redshifts, luminosities, and greater detail on the nature of the objects are provided by spectroscopic identification campaigns, which constitute some of the most expensive observational followup.
The purpose of this web site as a community resource is multifold:
- to compile a list of recent and ongoing surveys which include Chandra and XMM Newton X-ray data and to provide links to the surveys' main web sites.
- for each X-ray survey to list all the surveys undertaken at other wavelengths in the same area of the sky and include some survey characteristics and results.
- to provide a tabular format (currently in the form of a Google spreadsheet) of the collected information. This table of X-ray and multiwavelength surveys has the goal of being a "living" document that can and should be continuously updated if new data is collected or new results and numbers are obtained and published.
- to facilitate survey science by also providing links to public data, catalogs, and other products for the various surveys.
Given the tremendous amount and variety of observations performed by the current and previous X-ray observatories we had to limit the number of X-ray surveys included. To begin with, only surveys executed with the current large X-ray telescopes (i.e. Chandra and XMM) and with total exposure time greater than 200 ksec have been included in the compilation.
We encourage representatives of the various X-ray surveys to sign up for a Google account (for which you can use an existing email address), and to contact us at xsurveys06@cfa.harvard.edu so that we can give you edit-capable access to the spreadsheet. Anyone is encouraged to contact us with suggestions and corrections for the site as well.