We appreciate all the comments and questions in your survey responses.
If you left an email address we have responded to your concern or questions.
Sometimes, due to the short nature of survey responses, we may not entirely
understand the issue raised and we apologize if we did not respond in a useful way.
If you had a concern or question that is not addressed below PLEASE contact us as we
would like to discuss it with you.
We are always eager to address issues and hear from you, so please contact us
with any problems or issues that arise.
If you would like to use the archive in a new way and the current services don't provide
you with the tool that you need or you are having a problem with a service or tool we
please contact us through the help desk email@example.com
or by phone (410-338-4547) between 9:00 AM and 5:00 PM Eastern time.
We also provide a Suggestion Box for you to submit requests
In your front search page (http://archive.stsci.edu/), please make one of the resolver options 'Don't Resolve'! Currently the only two options are 'SIMBAD' and 'NED' but neither works for some things (e.g., solar system objects).
Thank you so much for your suggestion. This has been implemented.
I would like to see a little more support for multi-object searching
We do have a couple of methods for supporting searches for multiple objects.
For all our mission searches and the cross-mission search,
we have a file upload form that is similar to the search form.
Instead of having form elements for coordinates, it permits you to "upload"
a file containing a list of coordinates, targets or dataset names (data ids).
If you upload target names you can choose NED or SIMBAD to resolve them.
If you want to search without resolving them, we suggest you surround each name
with asterisks to serve as a wild card.
We recently had a question about uploading lists of coordinates to
our GALEX search form. Our current Simple GALEX search form does not
support uploading lists. However, one can accomplish the same result
by uploading the file list to our Cross correlation page at
Marking the RA and Dec columns as appropriate,
and click on the GALEX box. This will do a "cone search" on your search radius around
each of these coordinates and return the result.
If this does not address your needs, please contact us as we are interested in
supporting our users when possible.
VizieR Catalog tool doesn't work well.
We understand that this tool is sometimes slow.
This is partly because we query and retrieve the catalogs from VizieR.
Sometimes the network connection is slow and so it takes several minutes
to retrieve the catalog. In addition, the contents held in memory.
This means that if the server is being heavily used
the response is slowed even further. We are moving (or just moved) to a new
webserver and we hope that will improve the response somewhat.
As resources permit, we will also look into other methods of improving the response.
What is the difference between MAST FUSE Science and MAST FUSE Exposures?
FUSE observations are taken as a series of exposures.
The FUSE Science search searches a database that
contains information on the observation level. Most users will find the
observation level information the most useful.
The FUSE Exposure search
is not used often but does provide access to exposure level meta-data (keywords).
Incorporate NED and SIMBAD results to the targets searched for.
Near the top of the search results page there is a summary of the target information
retrieved from the resolver. The resolved target name is a link to NED or SIMBAD
results for a search on that target.
A few people said something like "Download times for HST Data are SLOW" while
others stated that the speed of retrievals is fast enough
The planned HLA should speed access to the public data.
The data will be preprocessed and available for download immediately.
The initial HLA release will contain 20% of the public ACS data.
The STIS data have all been reprocessed and ingested. The data will no longer
be reprocessed for each request and so access to these data from DADS should be
For the HST legacy instruments (FOS, GHRS, FOC and shortly STIS) data have been
staged on spinning disk in an anonymous ftp site.
There is a web interface called HSTONLINE
that allows users to search among these instruments and download data directly
to your desktop as the IUE, EUVE, and ASTRO data are. We expect this function
to be incorporated into the HLA interface in the future.
Have sftp available for downloading data.
SFTP is an option if you ask DADS to push data to your computer. However, as you note,
sftp is not an option if you are downloading data from the stage area. The software that
we use to authenticate users and protect proprietary rights does not support sftp, so we
are not likely to support it in the future.
At present, I do not find it straightforward to download data to my laptop as is is possible to do with Spitzer software tools. Thus I end up with a two stage process, downloading the Spitzer data to my desktop and then transferring it to my laptop where I actually do most of my work.
We assume that you are downloading HST data to your desktop and transfering it to your laptop.
Are you asking DADS to push the data directly to your laptop or are you having the data staged
and then downloading it via ftp to your machine? It is hard to diagnose the problem from
this description. Some systems require that you use the sftp protocol when having DADS push the
data to your machine, while others will not permit use of sftp. For DADS downloads (HST and FUSE)
you need to check the sftp option on the request form.
Sometimes network administrators also have permissions set requiring one type of ftp or another.
However you should be able to download data directly to your laptop.
When you have this type of problem, please contact the archive help desk
Many of our users perfer to have the data staged in an ftp area here at STScI on archive.stsci.edu
where they can come and ftp the data to their machines.
Be sure binary is set before beginning to ftp data from archive.stsci.edu.
The HLA will provide a quick, direct download method once it is fully operational.
Since the Early Data Release will have only 20% of the ACS data available it will not be
as useful as later releases. If you are interested in the legacy data (FOC, FOS or GHRS),
you might want to use the HSTONLINE interface which will tar up the data and
place it on your platform via your browser. STIS data will be added to this interface
after the MAST website is moved to a new server.
My principal interest would be to know, after MAST serves me a/some GALEX file(s) and I choose one and see a thmb sketch I like, *which* of the many downloadable images I should get. Knowing nothing detailed about GALEX formats, I would like to know which of the various FITS images I should download to quickly look at in IRAF and compare with optical images of the same object. I would like to know: Is there a single FITS image that is "flat-fielded"? What is its scale? Can I extract (sum) counts from it and do at least relative photometry of different regions with it?
The array of files generated by the GALEX pipeline can be baffling to the uninitiated and
even experienced users. MAST has information on several pages that attempt to explain what
the files are and which files should be used. You might start with the
Getting Startedpage which includes a
brief description of the types of files included in GALEX archive.
Under the Documentation link is the
FAQ:MAST:GALEX Data Description.
This describes the filenaming conventions and includes a comprehensive table of all the
file types with a description of the data in them.
A link to this table is also included in the "Getting Started" page.
Similar descriptions of the files can be obtained also at the GALEX GI site at :
In general, the data will have a filename with the format:
<xxxxxxx>[n/f]d-int.fits, where <xxxxxxx> is the filename prefix (e.g. HDFN_01_0001),
n represents NUV and f represents FUV. An example filename is: HDFN_01_0001-nd-int.fits.
GALEX images are already fully calibrated in c.g.s units and do not need
bias/background/flatfield corrections. Only certain raw files are expressed in counts.
I find the MAST web site very useful, but not well organized and not so easy to navigate and find your way around.-- A primary web page with a list of all services (some sevices are well hidden).
We have tried to organize the website and have explained our thinking in the
tutorial. We have found it a challenge
to include a lot of information in as flat an aspect as possible.
We do have a list of all services as a web page (linked to from the "more"
under the tools and mission_search menus on the top naviation bar or from
the "getting started" page under the category of "Finding Data").
We get a few comments each year that says the site is hard to navigate, along with
several that say MAST is easy to use. We welcome additional specific
suggestions if you care to drop suggestion in our "suggestion box".
Hubble Legacy Archive
A secure way for the HLA to work with datasets that are still proprietary.
Dealing with proprietary data within the HLA is something that is on the list of
items for the HLA, although at a low priority.
Search for images at any of an extended list of positions
At least initially, you will not be able to search on an extended list of positions
through the HLA interface. You are still able to upload a list of targets,
coordinate sets or a list of dataset ids with the
regular MAST interface. You can can bring up this form by clicking on
the option "File Upload Form" just under the title on the search to the
right of the page.
1) coaddition of largely (say more than 70 %) overlapping images, even if taken
in different orbits. 2) search for exposures longer than a given staked (i.e. integrated
over all exposures) exposure time (e.g. sky locations with F850 texp>10000s) 3) search for
sky locations satisfying an user request and holding on two (or more) "requests" (say,
F814W with texp>5400s *and* F475W with texp>6000s)
For suggestion 1, the HLA will ultimately have the tools you want for searching
for coaddeddata. The HLA footprint services will provide much more sophisticated
geometrical searches for things like regions of the sky with specified exposure
and filter coverage (and will also provide the ability to search for regions
covered by several different observatories, once VO footprint services become
more widespread.) The HLA will also provide deep mosaiced images combining
data from different visits.
Neither of these capabilities will be available in the HLA early data release, but they are
both planned for future releases. Mosaic images should be available by the end of this year
or early 2008.
In response to Suggestions 2&3, we do have an interface that might meet some
of these needs now that we call our "pointings" search interface. It is located at
The pointings interface queries a database that is essentially a summary of observations
made of specific sky regions. While you cannot search on specific filters you can search
on bands and the sum of all the exposures in that band per sky region.
So using the search criteria given in suggestion 2 above,
111 "pointings" were found where z band was exposed
for more than 10000s for all observations in a region. The interface allows you
to drill down to the specific datasets on the results page.
You can do something similar the criteria in suggestion 3 above. When the qualifications
z > 5400 and B> 6000 are entered into the interface, 54 pointings were found meeting
SuperCOSMOS has better blue plate coverage for southern hemisphere DSS images as well as excellent hydrogen-alpha - I don't understand why MAST can't have all this data in one site.
The reason the data at the WFAU and MAST are different is because the two
groups have different goals and have two separate data sets.
SuperCosmos was specifically built to digitize ALL the Schmidt plates taken
at the UKSTU for the science of the UK astronomical community.
Here at STScI, we digitized only a subset of Schmidt plates from both
Palomar and UKSTU primarily to support HST observations. The main difference
that you see is that we did NOT use the standard blue survey plates in the
southern galactic plane (about 96 fields) because they are too crowded to
allow us to accurately measure positions of targets and guide stars.
Instead, we obtained short exposure plates for these fields which do not go
as deep and are not as crowded. We have since digitized these 'missing'
standard survey plates and will make them available on our website when
resources permit. Similarly, we do not have scans of the southern H-alpha
survey since they are not required for HST observations.
When the HST project finished creating the DSS, the maintenance of that
archive was transferred to MAST which is primarily a repository for all the
NASA optical/UV data. SuperCosmos data does not fall under that category so
we cannot justify to NASA spending enough money to obtain sufficient
hardware (both are multi-Terabyte archives) and manpower to integrate them.
Updates to the OTFR pipeline sometimes result in substantial changes to the data products retrieved from MAST. Under some circumstances a MAST user may want to register to receive a notice when the OTFR pipeline is changed in a way that would affect the data they have retrieved. This may be a non-trivial feature to add, and perhaps the pipeline is at a stable point now where such notices are not really needed. Something to consider.
There are several ways the ACS+WFPC2 team trys to relay this information
to users... STANs, ISRs, a reference files webpage, and an online forum.
1. STANs are sent out by the imaging team approximately twice per year and describe the most
significant calibration activities and ISR which have recently come out.
These can be viewed at the website:
Users can subscribe to the email list by following the instructions on the webpage.
Unfortunately, the newsletters are not published very frequently.
2. ISRs give the most technical description of recent calibrations.
The ISR webpage is updated regularly to reflect new reports, AS THEY
ARE PUBLISHED. This is the best way to read about the most current
calibration activities. No calibration products are delivered without an
associated ISR, so users can review the ISR titles and decide if these
new calibrations are relevant to their science.
You used to have a feature where the DSS overlay was visible with WFPC2 archive data- can't seem to find it now.
That feature no longer exists. However the HLA footprint service will replace
this functionality. The Early Data release will include about 20% of the
ACS footprints and all of the WFPC2 and STIS footprints. As more ACS data is
processed, more footprints will be included. No WFPC2 or STIS data will be available
through HLA as part of the Early Data release.
What I have missed the most is *finding* MAST access to GALEX data for some specific galaxy, be it from NED, via the GALEX home page, or otherwise. Somehow, the fact that MAST serves GALEX images seems hidden. Better crosslinks from other sites (esp. NED) would help. Example: Am looking up my favorite galaxy on NED. Don't find GALEX images there. Have to know that I can click on some MAST link near bottom of NED display. But even that link does NOT bring up any info about my current-interest galaxy. Have to go somewhere to upper left and click on some 'Search form' link or the like. Cumbersome, should be easy to do better than that.
To rephrase the question, how do users find an object name?
The short answer is that many objects are not registered by NED or
Simbad, and therefore it is actually more robust to do a search on the
coordinates using a small search radius on the GALEX "Simple"
(MAST-like) form. Of course, if your object is a familiar object
like M81, it will be registered and you can search on the object
name box. Otherwise, we recommend that you determine your object
coordinates, in decimal degrees or in ddmmss format, and conduct
a search on them - this is known as a cone search.
Resolving object names:
Are we being difficult or what? Actually, not, but bear with us
for the "why" details. Most of MAST's other missions are target-pointed
in nature, so the object's name is in a local database. Because (say)
HST or FUSE PIs always publish their results, one is more likely to find
objects in these missions in a catalog that has made its way to Simbad
or NED for cataloguing. The object name is associated with coordinates.
When you the user types in an object name, this name goes out SIMBAD or
name and becomes "resolved" to the recognized coordinates for this
name. Note that M81 may have other names (like NGC 3031) and all of
these names will be resolved to the coordinates. When you initiate a
search on the object name on a MAST form, your search is really morphs
into a cone search around these coordinates. *If Simbad or NED is
unaware of the object name, a typical circumstance in 2007, your
named object will not be resolved to coordinates, and the search will
fail.* This happens for searches on HST-observed objects, but not nearly
Stable object names:
The GALEX Project does not expect to complete a source identification
catalog for its observed objects until after the completion of the mission
operations. These will be names that will be frozen for all time and therefore
can be listed (with stable coordinates) in Simbad and NEDs catalogues
In the meantime, we are best off with coordinates. MAST tries to encourage
the community to adopt the "IAU Name" as it appears on every cataloged object in our
Explore pages. For example, this name for M81 is GALEX J095534.0+690351,
which is based on the photocenter of the object, as determined in the GR2
GALEX general release 2. These are MAST's suggested names only. If users
eventually published papers with these names, they will eventually get
tagged as such in the literature and incorporated into the SIMBAD and/or
NED catalogs - our encouragement may speed up the process. [Note that the
GALEX objectid's, e.g. 2486024515198387570, are of little help in this
regard because objects can have more than one objectid if the object
is observed in more than one observation ("tile"). Moreover, these numbers
will change when the data are re-released in the GALEX GR4!] The moral
of the story is that for a survey such as GALEX there are no stable names
for most GALEX objects in either the literature or in the cataloguing
services listings. As such most objects cannot be searched and found in
the MAST search tools. Savvy users may recognize that this is a problem
with searches on object names for other surveys, such as Sloan, too.
I'd like to retrieve spectral data in ASCII format.
Spectral data for IUE, HUT, BEFS, WUPPE, TUES, EUVE, HPOL, and Copernicus (if coadded) are
available in ASCII format, generally from the preview page. Near the bottom of the
page is a link "Download ASCII data". The FUSE project asked us not to
provide the data in ASCII format so we are following their directions. We will
look into the feasibility of providing HST spectral data in ASCII format.