This applet comes up with an image of the Center of our Galaxy as seen in radio waves.
The "Magnifier" button will turn on the Magnifier view to the right. Clicking the left mouse button in the main window selects a data voxel which will update the magnifier view.
You can replace the main view with a zoomed version by first selecting a data voxel in the main view. Next selecting a zoom factor from the choice menu in the "Zoom Over Selected Point" portion of the Zoom Control; then press the "Zoom" button. To zoom to an arbitrarily shaped box, click the box selector button under the pixel position display. Then hold the left button down over the main view while dragging out a box. After selecting a box in this manner, click the "Zoom to Box" button from the Zoom Control.