NOAO-Sky

NOAO-Sky is a visualization tool to help users find VO-compliant and publicly archived imaging data.

Caution:

This tool is only compatible W3C compliant browsers ( Mozilla, Firefox, Netscape). It is not yet functional in Internet Explorer or Safari.

Tutorials: Sky⋅Time⋅Access/Analyze⋅SIA⋅Query

The default page shows the footprints of several imaging surveys, including several in the NOAO Science Archive as well as a different color (labels are shown as groups of three in each of the four corners of the sky at the default zoom level 2). Also shown are six other NVO image archives: SDSS, Chandra, XMM, HST, INT, and GALEX. You can switch any of these archive wireframes on/off using the "Display and Search by Archive" menu.

• A background grid shows the coordinate system (Hammer-Aitoff).
• At the top of the page are links to the other NOAO NVO Portal Tools: Time, Access/Analyze, SIA, Query, and Sign-in.
• The NOAO-Sky contains control-centers as pull-down menus on the left hand side of the sky-view (below the NOAO NVO Portal description and summary). Each is described below.

The NOAO-Sky is interactive. The DESCRIPTION Panel (shown in the graphic) is opened and describes the main features of the NOAO-Sky: You can click and hold your mouse button anywhere in the sky image to pan around. You can choose higher zoom levels using the zoom-bar in the top left of the viewer. You can double-click the mouse on a piece of the sky to find out what data is available at that point on the sky. The RA and DEC of the mouse (as well as the zoom level of the view) are shown in the white box at the upper left of the skyview. They change interactively. The zoom bar can be clicked or dragged to change the zoom level. Please be patient as each zoom level loads into your browser.

Add a Marker and Crossmatch

The first control-panel, Add a Marker and Crossmatch (shown below) can be accessed by clicking to open the pull-down menu.

Coordinates may be supplied in one of two ways: upload a file containing coordinates click the "Browse" button to specify the file enter the filename and click "Upload" type coordinate pairs into the dialog box The format for coordinates must be one of: sexagesimal (with RA specified in hours) decimal degrees a combination of the two Note that sexagesimal format must be specified completely: Degrees/hours, minutes, and seconds must all be present and delimited by a colon. Specify one set of coordinates per input line; include a comma to separate RA from Dec (and optionally, time). Click the "Add" button to place a marker on NOAO-Sky at each specified coordinate. The markers are shaped like a red "X" and blink for a short while after they first appear.

Once the coordinates are added to the list of markers, the user can choose to cross-match against the images within the cache of the NOAO NVO Portal. Any image wireframes which overlap points in the cross-match list are displayed below the NOAO-Sky in the GRID VIEW, shown in the bottom panel below:

If the observation time was included in the coordinate list, only those images which overlap in both space and time are listed in the GRID VIEW. Images in the GRID VIEW are reside in the Portal cache and can be: downloaded viewed (if previews are available), or added to a cart for further analysis

Fly-To

The second control panel (click on "Specify Object Name or Sky Location") allows users to pan and zoom directly to some specifed location.

As shown in the example at left, to go directly to M31 (the Andromeda galaxy) do the following: type "m31" into the Object form box click the "R" button to resolve the coordinates for this object or enter the coordinates directly decimal degrees sexagesimal (with RA in hours) choose a zoom level from the drop-down menu click on the "Go" button

Notice the position and level in the white box at the the top left of the NOAO-Sky view, as shown below:

Display & Search

The third control-panel enables a selection of archive wire-frames to be displayed on the NOAO-Sky. Choose "Display and Search by Archive" from the pull down menu.

Click the “check box” next to an image archive to turn on/off an archive. Hover your mouse over the archive name for more information about the archive. Click the archive name to go directly to that archive in a new browser window. The following archives are available: SDSS-DR5 HST CHANDRA XMM INT Wide Field Survey GALEX GR3 Caution: XMM, HST, and CHANDRA are "live" archives that are continually being updated with new data. The wire-frames shown in NOAO-Sky are updated every few months.

A search for datasets within the region of interest can be initiated with the "Search" button. Metadata for the matched images will appear below the Sky panel, as shown below:

The RA/Dec range for the search is defined by the viewing window and shown below the "Search" button. The GRID VIEW shows the images within the range defined. Note that the Skyview changes from Aitoff to a Lat-Lon projection at zoom level 7.

When the GRID VIEW shows data, the user can choose to retrieve the image directly from the image SIAP archive service. For instance, the user could choose to download the fits image directly to their DS9 viewer.

If a preview image is provided by the SIAP service, a link is provided to view that JPG (or GIF or PNG) in a pop-up window. Note that the browser must allow pop-ups to use this feature.

Finally, users can select data to add to their Access/Analysis Cart, as illustrated below:

Users can add any or all images to their cart. To use the features of the Cart, click on the Access/Analyze tool on the toolbar at the top of the frame.

Tutorials: Sky⋅Time⋅Access/Analyze⋅SIA⋅Query