The XTEAO database table contains the official observing program for the Rossi X-Ray Timing Explorer (RXTE) satellite. This list contains the targets recommended by the review panels for the various Cycles of Guest Observer (GO) proposals up to and including Cycle 15. Notice that not all entries in this list will actually be observed, since it includes observations of Targets of Opportunity (ToOs) which may never be triggered. Also note that multiple pointings at a particular target are permitted. This database table was updated by the HEASARC periodically, based on information provided by the RXTE Guest Observer Facility (GOF). This is a service provided by NASA HEASARC .

The X-Ray Imaging and Spectroscopy Mission (XRISM) is an international mission led by Institute of Space and Astronautical Science (ISAS) of Japan Aerospace Exploration Agency (JAXA). XRISM was launched on 2023 September 6 (UT) into a near-circular orbit with an apogee of ~575 km, an inclination of ~31 degrees, and an orbital period of about 96 minutes. During the performance verification (PV) phase, targets selected by the XRISM science team are being observed. Subsequently, it will become a general observatory with annual call for proposals open to all astronomers. XRISM has two co-aligned instruments that are used concurrently: Resolve, a soft X-ray spectrometer, and Xtend, a wide field-of-view imager. Resolve uses an X-ray microcalorimeter with ~5 eV spectral resolution withs a 3x3 arcmin field of view. It is currently operating with the Gate Valve closed, which limits its effective bandpass to 1.7-12 keV. Xtend is an X-ray CCD instrument with a 38 x 38 arcmin² field of view. This table contains a list of observations that have taken place as well as those that have been accepted and planned. The latter includes pre-approved targets for TOO observations and priority C targets whose observations are not guaranteed. This database table is based on information supplied by the XRISM Science Data Center at NASA/GSFC. It is updated automatically on a regular basis. 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 .

The ROSAT International X-Ray/Optical Survey (RIXOS) is a medium-sensitivity survey and optical identification program for X-ray sources which were discovered in ROSAT high Galactic latitude fields (|b| > 28 degrees) and observed with the Position Sensitive Proportional Counter (PSPC) detector. The survey made use of the central 17 arcmin of each ROSAT field. A flux limit of 3 x 10^-14 erg/s/cm² (0.5-2.0 keV) was adopted for this survey, and a minimum exposure time of 8000 seconds was required for qualifying ROSAT observations. X-ray sources in the survey are therefore substantially above the detection threshold of each field used, and many contain enough counts to allow the X-ray spectral slope to be estimated. Spectroscopic observations of potential counterparts were obtained of all sources down to the survey limit in 64 fields, totaling a sky area of 15.77 square degrees. Positive optical identifications are made for 94% of the 296 sources thus examined. A further 18 fields (4.44 sq deg), containing 105 sources above the 3 x 10^-14 erg/s/cm² survey limit, are completely optically identified to a higher flux of 8 x 10^-14 erg/s/cm² (0.5-2.0 keV). Optical spectroscopic data are supplemented by deep CCD imaging of many sources to reveal the morphology of the optical counterparts, and objects too faint to register on Sky Survey plates. The faintest optical counterparts have R ~ 22. This table contains the catalog of the RIXOS sources and their optical identifications. This table was originally ingested by the HEASARC in June 2005 based on CDS table J/MNRAS/311/456/rixos.dat. It was updated in November 2013 shortly after the CDS released an update with the previously inadvertently omitted source RX J111809.9+212554 (RIXOS 123_84) included. This is a service provided by NASA HEASARC .