Data Explorer Tutorial v 2.0

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Data Explorer is a tool which allows the user to navigate through the SSDC and external catalogs and provides an easy way to explore large data sets from radio to GeV. It can be accessed at the SSDC home page (, from the "Quick Look Data" "Multi mission Archive" and "Tools" main menu tabs, and from the "SSDC Sky Explorer" panel.

Getting started

If you reach the Data Explorer, you have made a query to the "SSDC Sky Explorer" system for a specific source or set of coordinates ( The source position in the sky is displayed on the top right corner of the following figure. The input coordinates are shown at the top of the page and below the graphic frame, enclosed in a yellow, red-bordered rectangle. These coordinates are given both in RA/Dec (decimal and sexagesimal) and l/b systems, and represent the center of a 60 x 60 arcmin box opened by default.

Fig.1 This graphical box displays all the sources collected in the SSDC default catalogs in a 60 x 60 sky box centered at the give position. These sources can be listed clicking the "Source list" link below the grafical box. Information about each source can also be gathered moving the mouse on the circle corresponding to that specific source. The default catalogs can be viewed clicking the "i" tab close to "Default catalogs".

The tool starts by exploring a subsample of the vaste catalog database stored at SSDC. The complete database, as well as external ones, can be explored by the user through the "Additional Services" boxes, at the bottom of the main graphical page.

In the main graphical page, the following catalog selections are proposed to the user:

Default catalogs (always selected): by default, a list of ten selected catalogs are always queried since the first session.

Selectable catalogs: in addition to the above default catalogs, the user can perform additional queries by exploring the vaste catalog database stored at SSDC. A subsample of these catalogs can be selected from the lists grouped per energy band in the central panel. A list of five catalogs is proposed by default to the user (see "Default selection").

The complete database can be explored through the "Additional Services" area.

The list of chosen catalogs can be retrieved using the "Selected catalog list" button. A complete catalog name legend is also supplied, together with catalog references and links.

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Refining the search criteria

By clicking on a specific source on the left panel will cause the coordinates in the yellow, red-bordered box to change to the selected new source. The "Create new image" button will generate a new plot (right panel) centered on the new position. The dimension of the right plot can be adjusted using the "size (arcmin)" toolbox. Further centerings can now be performed also clicking on the rigth plot.

Source colors refer to catalogs according to their wavelengths, coherently with the central panel colors. A red cross in the right box represents the old set of coordinates, i.e., the central position of the left plot.

A new session on the original source coordinates can be re-executed at any time on a new graphical window by clicking the "Reset Position" button.

A spectral energy distribution for the selected source can be extracted by clicking the "SED Builder" button, located in the rigth region of the rectangular yellow box.

The SED tool tutorial can be found at:

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Additional services

The "Search SSDC Catalogs" panel allows the user to browse the internal catalogs (grouped by energy band) stored in the SSDC database, for sources around the current coordinates, in a user-defined search radius.

The "Search Other Services" panel queries external databases using the current coordinates and in a user-defined search radius. Both services display the results in a new window.

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Access to public data archive

Clicking the "Access to Public Data Archives" button will expand the Data Explorer window. The quick data viewer allows the user to search and download data from specific missions/databases in a user-defined search radius around the current coordinates. Missions and databases are ordered from top to bottom as the energy band decreases.

The "SSDC Algorithms" panel, links the user to figure of merit algorithms.

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