ROSAT Status Report #106:

To assign unambiguous names for ROSAT objects one should use the recommendations given by the IAU Commission 5 published in the following journals:

IAU Transactions, vol XXB (1990), pp S46-S4

Pub. Astron.Soc.Pacific, 102 (1990), pp 1231-1233

Astron. and Astrophys. Special Issue, March (1992), pp A11-A13

The recommendation we distributed formerly is correct, but may give ambiguities in more densely populated regions. We therefore propose to use one of the following three formats depending on the absolute (!) positional accuracy of the X-ray position and the density in the field:

arcsecond accuracy (RA 1.5", Dec 1.0"; at the equator)

RA(2000): 01h23m45.6s ; Dec(2000): -76d54'32" ---> RX J012345.6-765432

fraction of arcmin accuracy (RA 15", Dec 0.1'; at the equator)

RA(2000): 01h23m45s ; Dec(2000): -76d54.6' ---> RX J012345-7654.6

arcmin accuracy (RA 1.5', Dec 1'; at the equator)

RA(2000): 01h23.7m ; Dec(2000): -76d54' ---> RX J0123.7-7654

remember to truncate, not to round:

RA(2000): 01h23m45s ; Dec(2000): -76d54'41" ---> RX J012345-7654.6

RA(2000): 01h23m45s ; Dec(2000): -76d54'42" ---> RX J012345-7654.7

After a long prepatory stage we can now announce a working draft of the ROSAT Users Handbook (RUH). It is intended to provide ROSAT users with an overview of all technical aspects of the observatory and has been prepared in a collaborative effort between the experts of GSFC, SAO, the University of Leicester and MPE. Besides a description of the satellite, it deals with different mission aspects, describes the performance of the telescopes and instruments and covers with special emphasis the different calibration issues. Appendices contain a short mission history, a list of known problems and information how to access the different ROSAT services. For the coming years the RUH will probably go through many updates, and suggestions from your end will certainly help us in this effort. Later on (all chapters filled) we intend to distribute it also as a printed book. At present it is available via the online services of the data centers. In the ROSAT Service Area it can be accessed from directory doc/handbook in 2 flavours: a POSTSCRIPT and a LATEX version. The file README contains additional info. A WWW version (mosaic) is in preparation. (The RUH is also available from GSFC from the heasarc.gsfc.nasa.gov anonymous ftp account, under the /rosat/doc/users_handbook/ directory)

An update of the EXSAS Users Guide has been installed in the ROSAT Service Area (directory doc/exsasguide). A (compressed) POSTSCRIPT version and a LATEX version plus a README file are available. We are also preparing a WWW version (mosaic; see address header). A printed version of the EXSAS Users Guide and of the EXSAS Command Summary is in preparation and will then be distributed to the institutes.

A new EXSAS software patch is available in the SVC area. Read file exsas.status in directory exsas to learn about the changes.

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