When do data become publically available?
Data are publically available after the expiration of the data rights of the principle investigator. By the rules adopted by the international ROSAT user's committee, this expiration occurs 54 weeks after the completed data set is shipped from the data center to the PI.
A completed data set is one that has acquired either
- 70 percent or more of its allocated exposure time as good science time,
- or one in which no further observations will be obtained.
Another important aspect to the question of data availability is the physical transfer of data to the public archive. In the US, this transfer means the moving of data from the US data processing center's private archive to the HEASARC public archive. ROSAT data that has been processed at the US data processing center typically enters the HEASARC archive within two weeks of its scheduled public release date.
The movement of German and UK data processed at MPE is more complicated. For these data, data tapes are sent from MPE to the US, where the data tapes must first be ingested into the US data center's private archive before being staged to the NDADS public archive. This is a longer process, which means that there can be a delay in access to public German and UK data from the US archive. This delay is typically about a month, although we are working to minimize this delay as much as possible. There is a similar delay in access to US data from the MPE and UK archives for exactly the same reason.
Page Author: Michael F. Corcoran
Last modified April 28, 1999
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