Various services have been implemented around the ROSAT archive at MPE. Here we introduce these and provide links to running them.
ROSAT query services
GAVO has implemented IVOA standard query services on various ROSAT archives.
In particular, we have implemented simple cone searches (follow this link? for the specification) on catalogues derived from the ROSAT All Sky Survey RASS). The Bright and Faint Source Catalogues were loaded into a relational database and a simple query interface provides access to this database for performing a cone search. These catalogues are relatively small and could also be downloaded directly from the ROSAT archive at the Max-Planck-Institut für extraterrestrische Physik (MPE).
A new product GAVO offers is a cone-search on the photon event file, containing all the photons observed in the RASS. The same user interface offers query capabilities. The size of this catalogue, which contains about 100 million photons, put more requirements on the tuning and indexing of this database. For a description of the methodology we have used there can be found here.
We have also implemented the Simple Image Access Protocol (follow this link for the specification) on all the ROSAT images, both the fields derived form the all sky survey and all the pointed opbservations.
The services can be obtained via the button below.
RASS Source Identification with ClassX
The ClassX team has developed a set of tools for the classification of ROSAT sources (McGlynn, Suchkov et al., 2004). The tools are oblique decision tree classifiers using the OC1 implementation. The classifiers come in various flavours, depending on the amount of information about the source that must be provided, which is directly related to the information used in teaching the classifiers. Most of the classifiers require more information than can be obtained from the ROSAT data itself. For example some require information from optical, infrared and/or radio wavebands. To obtain this information therefore requires an identification between the ROSAT sources and sources in other catalogues.
In the GAVO prototype discussed here we use one particular classifier that has been made available via HTTP POST by the ClassX team. This classifier requires an identification between the ROSAT sources and the USNO-B1.0 catalogue for optical information. It further requires an indicator of whether an identification can be made with a source in either the SUMSS or the NVSS radio catalogues. All these catalogues are published by VizieR, which offers a "list upload service" which is very useful for our purposes. This service allows one to upload a list of positions and it will do a cone search around each of the positions, and the application makes extensive use of this feature.
To go to the application in a separate window click the button below.
Acknowledgements
We thank the ClassX team for their cooperation in this project, We especially thank Erik Winter for frequent and quick help with the ClassX web service.