XCOLL - Master X-Ray Collimators Catalog Database
The XCOLL database is a master catalog which contains 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
* 3ARIEL - 3A (Ariel V) Catalog
* 4UHURU - 4th UHURU X-ray Catalog (Forman et al. 1978)
The XCOLL database has 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` which
indicates from which original catalog database the entry was copied; users can
"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 example, to access the help for the A1 catalog while XCOLL
is loaded as the current database, type "dbhelp/dbname=A1".
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 catalog designation is the name of the source as assigned in the particular
catalog from which it comes.
This is a running serial number used within some of the catalogs to indicate
The name of the HEASARC database from which this entry was taken.
(For more information on the contents of any of the HEASARC databases, type
`dbhelp/dbname=xxxxx` where `xxxxx` is the database name.)
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 count rate associated with the source (counts per second). The associated
error parameter is `count rate error`.
The flux in milliCrab.
`Flux mCrab error` parameter contains the error associated with `flux mCrab`,
also in milliCrab.
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 name of the filter used for the observation, if any.
The exposure time for the observation, in seconds.
The observation sequence number for the source, if present.
The probability that this source is a result of background fluctuation.
The size of the source if it is extended, in arc seconds.
The BROWSE object classification flag.
Questions regarding the XCOLL database table can be addressed to the
HEASARC User Hotline.
If you have any problems, please consult the help
page or mail firstname.lastname@example.org