ROSAT Guest Observer Facility

Information on Accessing the ROSAT Data Archive at GSFC

Searching for ROSAT Data Using Browse or Xamin

The catalog of ROSAT PSPC and HRI archival data can be searched using the HEASARC Browse or Xamin interfaces. The main catalogs of archived ROSAT data are:
  • ROSMASTER: the catalog of ROSAT pointed observations with either the PSPC or HRI
  • RASSMASTER: the catalog of ROSAT All-Sky Survey scanning observations with the PSPC
Searches can be done by position, time, target name, and other parameters.

Direct Access to ROSAT Data

Users can also access public ROSAT data directly from the HEASARC web server. ROSAT data are stored within directories numbered by sequence type as follows:

Sequence Type Category
000000 Mispoints
100000 Calibration observations
200000 Normal stars
300000 Cataclysmic Variables
400000 X-ray Binaries
500000 Supernova Remnants
600000 Galaxies
700000 Active Galaxies
800000 Clusters of Galaxies
900000 Solar Systems, Surveys and Miscellaneous

ROSAT data are located at:

Data are divided into subdirectories from 100000 to 900000 based on the sequence ID of the data based on the catagories in the table above. Thus the dataset rp500065n00, a PSPC pointing at Crab nebula, can be found in The dataset rh400344n00, an HRI pointing at the Vela Pulsar, can be found in

Historical Notes

Release of Data to the ROSAT Data Archives

ROSAT pointed-phase data had a proprietary period of 1 year after the completed dataset were delivered to the principal investigator of the observation. After expiration of the proprietary period, the data were released into the ROSAT Data Archives (RDA) at the Goddard Space Flight Center (GSFC) in the US, at the Max-Planck-Institute fuer Extraterrestrische Physik (MPE) in Germany, and at Leicester University in the UK. The US ROSAT Data Processing Center was responsible for the processing and release of data obtained by US PIs, while MPE was responsible for the processing and release of data obtained by non-US PIs. Although every effort was made to have all public data available at each archive site, inevitable delays in data exchange between the US and Germany meant that non-US data often appeared first in the MPE archives, while US data generally appeared first in the GSFC archive. The GSFC and MPE archives currently contain all observed and processed ROSAT data.

A Brief Word about ROSAT Data Formats

Until the start of REV2 processing in 1994, ROSAT data produced at the US Data Center at GSFC and data processed at the German Data Center at MPE were in different formats. That is to say, the files output used FITS as the basic file structure, but the details of the file structure differed depending on where the data were processed. These differences came about naturally as a result of the different analysis tools used on either side of the Atlantic: primarily MIDAS/EXSAS in Europe, and primarily IRAF/PROS in the US. As these data became public, they were released into the ROSAT Data Archives, with the result that tools which might work on one form of archived data might not work on the other form. This could cause inconvenience to archive users who, for example, might want to compare US and German observations of the same object.

With the start of REV2 processing, data were produced at the US and German data centers using a common data format, called the "Rationalized Data File" format. The RDF format uses FITS as the basic file structure, while specifying the details using approved multi-mission data structures and keywords. The REV2 data in RDF format represents the final ROSAT archive product. At preent, all ROSAT data in all ROSAT Data archives are stored RDF format. That is to say, data previously released were re-processed in RDF format, and data in the older format were removed from the archives.

For More Information

Contact the ROSAT help desk via the Feedback form.

Page Author: Dr. Mike Corcoran

Please use the Feedback link if you have questions on ROSAT.

This file was last modified on Wednesday, 20-Oct-2021 11:00:19 EDT

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