XCOLL - X-Ray Collimators Catalogs
XCOLL was a master catalog which contained selected parameters from HEASARC X-ray catalogs containing the results of surveys made with collimated detectors. In general these sources have error boxes that are relatively large and irregularly shaped. XCOLL was created by copying all of the entries and common parameters from the following catalogs:
* A1 - HEAO 1 A-1 X-Ray Source Catalog * A2LED - HEAO 1 A-2 LED Catalog * ARIEL3A - 3A (Third Ariel-V) Catalog * UHURU4 - 4th UHURU X-ray Catalog (Forman et al. 1978)The XCOLL database table had many entries but relatively few parameters; it provides users with a general overview of X-ray sources detected with collimated detectors. Each entry in XCOLL has a parameter called 'database_table' which indicates from which original catalog database the entry was copied; users should "browse" that original catalog should they wish to examine ALL of the parameter fields for a particular entry.
Also, to obtain more detailed information about original catalog, or about the instrument used in the experiment, users should access the online help for that catalog.
For some entries in XCOLL, certain of the parameter fields are blank (or have zero values); this indicates that the original database did not contain that particular parameter. (For example, the 'flux_mCrab' parameter is often blank for this reason.)
The commonly-used name of the sources.
The Right Ascension of the X-ray source, in degrees.
The Declination of the X-ray source, in degrees.
The galactic longitude of the X-ray source.
The galactic latitude of the X-ray source.
Right Ascension of the first corner of the error box surrounding the source.
Right Ascension of the second corner of the error box surrounding the source.
Right Ascension of the third corner of the error box surrounding the source.
Right Ascension of the fourth corner of the error box surrounding the source.
Declination of the first corner of the error box surrounding the source.
Declination of the second corner of the error box surrounding the source.
Declination of the third corner of the error box surrounding the source.
Declination of the fourth corner of the error box surrounding the source.
The catalog designation is the name of the source as assigned in the particular catalog from which it comes.
The count rate associated with the source (counts per second). The associated error parameter is 'count_rate_error'.
The error in count rate.
Database table this entry comes from
The probability that this source is a result of background fluctuation.
The position error radius. (Note: All values are zero as populated.)
The exposure time for the observation, in seconds.
The name of the filter used for the observation, if any.
The flux in erg s-1 cm-2, usually obtained by multiplying the given count rate by a conversion factor. The 'flux_error' parameter contains the associated error, in the same units.
The uncertainty in the flux, in erg s-1 cm-2.
The flux in milliCrab.
This parameter contains the error associated with 'flux_mCrab', also in milliCrab.
The observation sequence number for the source, if present.
This is a running serial number used within some of the catalogs to indicate source order.
The size of the source if it is extended, in arc seconds.