The EXOMASTER database contains the EXOSAT observation log. This is a complete list of all EXOSAT observations, observing modes, and principal investigators. The log can be used to find out which targets were observed by EXOSAT, who observed them and the observation configuration. In addition this database can also be used to check the availability of the FOT (Final Observation Tape) files (the original raw data files) and their reformatted FITS files. This database table was originally created in September/October, 1997. The HEASARC revised this database table in August, 2006, in order to fix the equatorial coordinates (which were in the wrong equinox) and to rename or convert some of the time-related fields to better conform with current HEASARC practices. This is a service provided by NASA HEASARC .

This database table contains the EXOSAT observation log. This is a complete list of all EXOSAT observations, observing modes, and principal investigators. The log can be used to find out which targets were observed by EXOSAT, who observed them, and the current state of the data analysis. The HEASARC revised this database table in August, 2005, in an effort to modernize its parameter names and add Galactic coordinates. This is a service provided by NASA HEASARC .

This is the first online version of the EXMS catalog. It contains information on the 1210 sources detected by EXOSAT during slew manoevers between 1983 and 1986. Each detection was obtained by searching for excesses above the background level in the light curve, fitted with the expected triangular profile due to the source passing from one side of the collimator to the other. These light curves are available for inspection from the xray account at ESTEC/ESA (telnet :://xray@exosat.estec.esa.nl). The detection time, raw 1-8 keV count rate and position (based on the centroid of the uncertainty region) are given for all 1210 entries. 80% of entries have proposed single identifications, obtained by cross-correlation of the uncertainty region against other catalogs. For these sources, the count rates are also supplied after correction for collimator efficiency, normalised to counts/sec/half, where "half" refers to one half of the ME detector array. This ensures consistency with the entries in the ME database. Coordinates of the proposed counterpart are also given, together with object type. The remaining sources consist of cases where more than one plausible candidate lay within the uncertainty region or where no candidate could be found. For these cases, only raw count rates are supplied. This database is a modified copy of the exms databases available from ESTEC/ESA. It was re-built by the HEASARC in July 1999. This is a service provided by NASA HEASARC .

The XRAY database table contains selected parameters from almost all HEASARC X-ray catalogs that have source positions located to better than a few arcminutes. The XRAY database table was created by copying all of the entries and common parameters from the tables listed in the Component Tables section. The XRAY database table has many entries but relatively few parameters; it provides users with general information about X-ray sources, obtained from a variety of catalogs. XRAY is especially suitable for cone searches and cross-correlations with other databases. Each entry in XRAY has a parameter called 'database_table' which indicates from which original database the entry was copied; users can browse that original table should they wish to examine all of the parameter fields for a particular entry. For some entries in XRAY, some of the parameter fields may be blank (or have zero values); this indicates that the original database table did not contain that particular parameter or that it had this same value there. The HEASARC in certain instances has included X-ray sources for which the quoted value for the specified band is an upper limit rather than a detection. The HEASARC recommends that the user should always check the original tables to get the complete information about the properties of the sources listed in the XRAY master source list. This master catalog is updated periodically whenever one of the component database tables is modified or a new component database table is added. This is a service provided by NASA HEASARC .