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Response to User Comments from the 2009 MAST Users Survey

We thank all the users that participated in our survey, and we appreciate all the comments and suggestions. If you provided your email address, we have responded to your concern or questions directly. Here, we provide responses to some questions and comments that we thought would be of general interest to our users (most of the comments have been edited or paraphrased). 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 has not been fully addressed, please contact us through the help desk or by phone (410-338-4547) between 9:00 AM and 5:00 PM Eastern time.

We always appreciate suggestions and feedback from our users. If at any time you are having a problem with an existing service or tool, or if we are not currently providing you with the tool that you need, please contact us.


I had no success in finding out about FUSE NVO files.

In May 2009, as part of the FUSE close-out, we deployed the FUSE archival website, which included new archival versions of the FUSE Instrument Handbook and FUSE Data Handbook. Information about the FUSE NVO files is given in the new version of the Data Handbook (which probably was not available at the time that you sent this comment), although we agree that it is not easy to find. Thank you for pointing this out! We will add some basic information and a link to the relevant section of the FUSE Data Handbook to the website.

A brief answer is that FUSE NVO files are compatible with Virtual Observatory (VO) Standards (SSAP v1.0) and contain a single spectrum spanning the entire FUSE wavelength range (905 ≤ λ ≤ 1187Å), created by cutting and pasting segments using the channel with the highest signal-to-noise (S/N) ratio at each wavelength. They have the extension *nvo*.fit and they will be automatically downloaded if you select "minimum recommended product" on the FUSE download page. You can also download them by explicitly selecting them by extension (scroll to the bottom of the 'Obs' list). The FUSE Spectra are also available online at The keywords are described at

For more details, please see the new archival version of the FUSE Data Handbook: The discussion of the NVO files is at the bottom of the page.


I would like to be able to get magnitudes for GALEX objects

The GalexView tool ( returns GALEX FUV and NUV object magnitudes, and you can sort based on those magnitudes (e.g., show only objects brighter than a given magnitude limit). We are currently working on integrating Sloan Digital Sky Survey object magnitudes as well - those will be available in the next release of GalexView.

GalexView does not work on my Linux box.

It should! Please contact for help.

It would be useful to be able to extract FITS sub-images (square of few arcmin) for target upload lists.

We plan to make this possible within GalexView in the near future.

I want to search the GALEX archive for a list of targets.

Unlike many other MAST missions, it is not possible to do this from the regular MAST search form for GALEX. However, it is easy to do from GalexView. Just click on the 'Upload' button in the upper left part of the GalexView page. You can then upload an ascii file containing the ra and dec for your list of targets.

Hubble Legacy Archive

It would be nice to have a field-of-view check, particularly for WFPC2 data

We're not sure what you mean by a "field-of-view" check. Do you want to see which region of the sky is covered by WFPC2 pointings? We call that a "footprint", and the HLA has a powerful footprint tool --- just click on the "footprints" tab on the HLA search page.

It would be really useful to have user accounts with custom persistent settings and history

We do plan to provide this capability in the near future, and are looking into how to implement it. It is likely that this feature will first be made available for the HLA only, and then eventually for the general MAST interface.


Add google search to the site.

We already have it! Just click on the 'Site Search' tab at the far right of the top bar. That will allow you to do a google search of just the MAST site or the whole internet.

Is there a way to find the published papers that make use of MAST data?

Yes! Please check out the new bibliography search tool at Also, links to papers using specific data sets are now provided in the search results of most mission searches in a field labelled "Ref". The numbers listed in that field indicate the number of papers using that data set. Clicking on a non-zero number will list the papers with links to the ADS.

Why doesn't MAST use a secure ftp server like sftp? I am worried about security when using regular ftp.

Because of the way our server is set up, it is not possible for archive users to use sftp to "pull" data from DADS to their computer. However, the only information that could be insecure is your archive username and password. This password does not confer any direct login privileges, so the only thing at stake is data retrieval from DADS. We think it is very unlikely that this represents a security issue, as long as you do not use the same password as any of your regular computer accounts (which we certainly would not recommend!).

If you still feel uncomfortable using regular ftp, it is possible to use sftp (OpenSSH v2) to have the data "pushed" to your computer (see Please contact the archive helpdesk if you have trouble getting this to work.

I would appreciate it if NICMOS data were directly downloadable, like WFPC2 and ACS data.

Now it is! NICMOS data are now available "online" as part of the HLA DR3. Check it out at

I want to be able to search for Solar System objects by target name within MAST. For example, I want to find a list of all UV observations of 'Jupiter' that have been taken with HST.

As users who study our Solar System know well, the usual NED and SIMBAD resolvers do not work for moving objects. This has been a long-standing problem for MAST. A starting point for HST data is to search on a target name such as JUP* with the resolver set to "don't resolve".

However, we realize that this solution is not ideal, and we are now starting work on a project to use an electronic ephemeris (which tells us the coordinates of a moving object as a function of time) in combination with a footprint tool (which can tell us which parts of the sky have been pointed at with a given instrument, at a given time, in a given filter, etc) to allow users to do searches like the example above for Solar System objects. We would particularly welcome input from the community about what you want and need from this kind of tool.

I want to be able to select a list of targets by type (e.g. all CVs brighter than some magnitude limit).

Searching by object type or class is more difficult than it might seem on the face of it, because for most types of objects, classification is subjective or ambiguous and there is no definitive catalog of all such objects. For HST data, it is possible to search by Target Description, which is a keyword supplied by the observer. It is also possible to search for HST datasets that contain certain words in the proposal abstract or title. However, these only specify the type of object that was of interest to the observer who wrote the original proposal, and a given observation may contain other kinds of objects. If you have a favorite catalog of the type of objects that you are interested in (e.g. CVs), you can upload a list of coordinates and search within a specified radius of each of those coordinates (click on File Upload Form on the main search page of most MAST missions).

We have started to work on a project which will make it possible to search for objects by type using links to published scientific literature. We are building a 'vocabulary' of words and relationships, based on words commonly found in the abstracts of papers that use data from MAST missions. We plan to use this to construct a tool that would allow users to search for datasets that have been used in papers that contain a specified keyword. We are also working on a 'spectral classes' tool that will allow users to search for stars with a specified range of spectral types. Both of these tools should become available within the next year.

In the past, I was troubled by the fact that some STIS high resolution echelle spectra did not have extracted spectra available -- only images could be obtained. I just did a spot check of a few spectra, and it seems that these spectra are now available. Is it correct that all of the spectra have now been extracted and are available as calibrated files?

We have recently completed a major reprocessing effort for STIS data, and many more extracted spectra are now available. However, there are still cases where we did not have the information required to extract the spectra, and are waiting for input from the PI.

The turn-around time for data retrievals from DADS is too long (12-24 hours)!

For the past several months, the median retrieval time for DADS requests has been about 1 hour or less, and this should generally be the norm. However, last Fall and Winter, many users may have experienced longer turn-around times because of frequent downtimes due to hardware problems and preparations for SM4. We apologize to those users, but anticipate that retrieval times should generally be no longer than 1-2 hours for the majority of requests. If your retrieval is taking much longer than this, please feel free to contact to see if there is a problem.

Replicate what is available on StarView for accessing MAST via a web browser.

We have been working very hard on doing exactly this -- we expect to release the new web-based StarView tool by early Fall of '09.

I would especially like to have a tool for coadding several spectra obtained for the same target in the same way.

It is possible to do this with SpecView, a Java-based tool that can be downloaded from SpecView is able to read HST, IUE, FUSE, ISO, FORS and SDSS spectral data, preview spectra from MAST, data from generic FITS and ASCII tables, and Virtual Observatory formatted data. We are also developing a new spectral plotting tool at MAST, which will probably include this capability.

I would like an easy way to download science-ready FITS format spectra for the missions that have ended, where no further improvements will be made to the data analysis.

We do make an effort to archive a final version of reprocessed data at the end of a mission or the end of an instrument's lifetime. For example, we worked with the FUSE project and with HST scientists to archive a final 'legacy' dataset for FUSE and for the STIS, GHRS, FOS and FOC instruments on HST. The data for the HST legacy instruments are available online (i.e., they do not have to be retrieved from DADS); see

These spectral data have also been formatted to be compatible with the VO Simple Spectral Access Protocol (SSAP) version 1.0. These files will be accessible from various VO applications but are also online as follows:

IUE low dispersion -