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HST Browse Files

Welcome to the Mikulski Archive for Space Telescopes (MAST). This page provides information on the HST browse files; a collection of web pages accessible from the MAST HST search results page.

The MAST HST preview pages are composed of GIF images of preview data, information extracted from the HST database, and when appropriate, links to display the FITS header, an interactive plot and this help page. The GIF images contain images or plots of calibrated fluxes in units of ergs/cm^2/sec/A, as a function of wavelength.

Previw FITS Header

The primary header of the FITS preview files can be displayed by clicking the "preview header" link. (Note extension headers are not currently displayed, and this option is currently only available for spectral data.)

Customize Plot Option

For spectral data, the HST preview page offers the option of displaying and modifying a plot of flux versus wavelength using data extracted from the CACD preview data files. Cutomizing the size and range of plotted values can be useful for viewing a particular spectral feature, or sizing the plot for better printing. Also, since unsmoothed fluxes are displayed, the plot can have better resolution than the original preview plot image. In addition to the plot, the output page displays the mission and target name, number of plotted points, and the min and max wavelength and flux values of the extracted data. See the Plot Help page to see plotting options.

The MAST HST preview webpages were created by the MAST staff using preview data obtained from the CADC.