Because Montage is written as a toolkit, its components – useful tools in their own right – can be used to support the development of new applications. We describe one application here: the IRSA Finder Chart service, developed by my colleague Mihseh Kong.
It returns images from all bands measured by three major astronomy image data sets: The Micron All Sky Survey (2MASS) , the Digitized Sky Surveys (DSS), and the Sloan Digital Sky Survey (SDSS). The service will return three color images, if requested, as well as “mirrored” images rotated 180 deg about the N-S axis (very useful at the telescope). The image shows a sample output: a 3-color image of NGC 5584 in the Sloan g,r and i bands.
The service uses the following Montage components:
- mArchiveList: Given a location on the sky, size in degree, and archive name, retrieves a list of archive images file names.
- mBestImage: Given the list of images from mArchiveList, the location, and size, determines which image has the best coverage of the location.
- mArchiveGet: Retrieves a single FITS image from a remote archive site.
- mGetHdr: Retrieves a header from a FITS file and write to a text file.
- mTANHdr: Analyzes a FITS header to determine if it can be approximated by TAN projection.
- mProjectPP: Projects an input image to a pseudo Tangent projection image.
- mRotate: Rotates and resamples an image an arbitrary angle.
- mSubimage: Retrieves a subset of an image.
I wish to thank my colleague Mihseh Kong for contributing material to this post.