The Multimission Archive at STScI (MAST) Newsletter disseminates
information to users of the HST, FUSE, IUE, Copernicus, EUVE, HUT,
UIT, WUPPE, IMAPS, BEFS, TUES and VLA-FIRST data archives supported
by MAST. Inquiries should be sent to archive@stsci.edu.
The FASST study made recommendations on instrument retirement,
user-contributed science data, and interface improvements, like
seamless searches of MAST and external archives. SHARE looked at data
processing and reprocessing, recommending improvements in several key
areas, like absolute astrometry, image combination, external catalog
usage, and object catalog production. With lower priority, SHARE
recommended STIS spectra combination and custom post-calibration
analysis scripts.
The two committees made some common recommendations. Chris Blades is
now leading a committee to scope, prioritize, and implement the FASST
and SHARE recommendations that require resources from multiple
divisions at STScI. The MAST team will implement some of the
recommendations, such as (1) the drafting of a policy for accepting
user-enhanced science data (high level science products) into the
Hubble archive and (2) completing the negotiations for storing the
final versions of the Goddard High Resolution Spectrograph (GHRS)
data, produced by the Canadian Astrophysical Data Center (CADC), and
the FOS data, produced by the Space Telescope European Coordinating
Facility (ST-ECF). (The GHRS and FOS collections will soon be
available from all three sites.)
STScI is now collaborating with the CADC and ST-ECF to provide WFPC2
data in the form of stacked and cosmic-ray-rejected images with
improved absolute astrometry by correlation with the USNO2 and the
GSC-II star catalogs. This project will also collect image statistics,
like object density and detection limits, which users could query in
archive searches. We expect that this project will extend in the
future to include optimized ACS science products.
The MAST scrapbook tool offers users the option of coplotting spectra
returned from a users query. A new feature is that a scale factor can
be specified interactively for each plotted spectrum allowing users to
more easily view overlapping spectra or determine rough flux ratios.
The coplotting tool is also accessible from both the IUE and EUVE
search pages. As with the scrapbook, the scale factor option is also
available for these spectra. Hopefully this tool will be added to the
other MAST search pages in the near future.
A new tool is now available from the main MAST page that allows up to
15 data sets (i.e., spectra from the STIS, IUE, EUVE, HUT, BEFS, TUES,
FOS, GHRS, or WUPPE) to be coplotted simply by specifying the MAST data
set names.
The simplest, quickest way to search for data on a particular object or
position is to use 'Quick Target Search.' This tool is available from
our main page at http://archive.stsci.edu. To use it, the user either
enters a target name, which is resolved by Simbad (the astronomical
database of the Centre des Donnees astronomiques de Strasbourg) or by
the NASA/IPAC Extragalactic Database (NED), or enters J2000
coordinates, where right ascension and declination are separated by a
comma. The Quick Target Search returns a list of all relevant MAST
datasets, including links to preview and dataset pages. By selecting
'Band/Data Type(s),' the user can restrict the search to specific
wavelength bands. The output page summarizes the available datasets
ordered by mission.
Using the spectral/imaging Scrapbook
(http://archive.stsci.edu/scrapbook.php),
the user can delve deeper
to peruse selected (preview) spectra and images from most MAST missions
(outside the Solar System). Using parameters like exposure times and
observing date, we have chosen these observations as 'representative'
of a named target or position on the sky. For spectra, we have selected
the maximum exposure time and lowest dispersion for a given
grating/wavelength configuration, which provides the broadest
wavelength coverage. For images, we have chosen on the basis of
exposure time, eliminating multiple pointings. In the Scrapbook, the
results page provides links to preview and dataset pages, where the
user can both learn what data are available and gain a multi-wavelength
view of the source. Using an option available for the spectral
Scrapbook, the user can co-plot representative preview spectra. After
selecting them, the user clicks 'plot marked spectra,' which displays
them all on a single plot of calibrated flux versus wavelength. The
result is a single, broad-band spectrum, possibly combining the results
of multiple instruments and missions.
If you would like remove yourself from the mailing list send mail to
archive_news-request@stsci.edu
and put the single word unsubscribe in
the BODY of the message. Information on the subject line will be
ignored.
If someone would like to subscribe to the mailing list they should
send mail to
archive_news-request@stsci.edu and put the single word
subscribe in the BODY of the message. Information on the subject
line will be ignored. The subscriber will be asked to confirm the
subscription.