The ATNF Visualisation Software

The ATNF visualisation software is a suite of tools (outside Miriad) specifically aimed at displaying spectral-line data cubes. See Chapter 3 for more information. The tools available are:

• kvis: This tool allows you to inspect one or two 2- or 3-dimensional datasets in several ways. This tool is partially described in Chapter 17.

• kslice_3d: This tool allows you to interactively inspect data cubes. The RA-DEC, RA-VEL and DEC-VEL slices of the data cube are shown simultaneously, and by moving the cursor one moves through the data cube.

• xray: This tool does volume rendering of data cubes. This is very useful for getting an overview of the emission in data cubes, as well as for finding small errors in continuum subtraction or the cleaning of the cube.

• kpvslice: This tool allows you to interactively display Position-Velocity slices through a datacube. It provides a window in which you can load an image (say an optical image or a moment map) and draw a slice across the sky. In the other window the corresponding slice through the datacube is displayed. This slice may be exported to Miriad for further analysis.

• krenzo: This tool will draw a contour map for every channel in a datacube over an image, using a different colour for each channel. This is a much better way of showing the velocity structure than using 1st moment maps, since a 1st moment map cannot show multiple peaks in a velocity profile.

• kshell: This tool computes and displays Velocity-Radius images from a datacube, allowing you to interactively browse for expanding shells. An expanding shell in a datacube appears as an ellipse in a Velocity-Radius image. This is an easy way of distinguishing between spherical shells and those which have distorted shapes (i.e. a gas bubble which has blown out through a galactic disc).

• koords: This tool allows you to easily add a coordinate system to an image (say a CCD image), by using a reference image (perhaps from the DSS). You select matching objects (stars) in the two images, and then press a button to compute a coordinate system for your target image.