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.
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.)
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.