XMMOMOBJ - XMM-Newton OM Objects
The Optical Monitor Catalog of serendipitous sources (OMCat) contains entries
for every source detected in the publically available XMM-Newton Optical
Monitor (OM) images taken in either the imaging or "fast" modes. Since the
OM records data simultaneously with the X-ray telescopes on XMM-Newton,
it typically produces images in one or more near-UV/optical bands for every
pointing of the observatory. As of the beginning of 2006, the data in the
public archive covered roughly 0.5% of the sky in 2950 fields. The OMCat
is not dominated by sources previously undetected at other wavelengths;
the bulk of objects have optical counterparts. However, the OMCat can be
used to extend optical or X-ray spectral energy distributions for known
objects into the ultraviolet, to study at higher angular resolution objects
detected with GALEX, or to find high-Galactic-latitude objects of interest
for UV spectroscopy.
OMCat: Catalogue of Serendipitous Sources Detected with the XMM-Newton
Kuntz, K.D., Harrus, I.M., McGlynn, T.A., Mushotzky, R.F., Snowden S.L.
=2008...K (SIMBAD/NED Bibcode)
This table was created by the HEASARC in March 2008, based on a table supplied
by the authors.
A unique XMM-Newton observation identifier made up of the proposal
number, target number of the proposal, and exposure number of the target.
A unique target counter for the OM source within the observation
specified by the obsid. Thus, the combination of obsid and obj_num uniquely
identifies an entry in this table.
The Right Ascension of the OM source in the selected equinox.
The Declination of the OM source in the selected equinox.
The Galactic Longitude of the OM source.
The Galactic Latitude of the OM source.
The position error of the OM source, in arcseconds.
The start time of the observation in which the OM source was
The duration of the exposure in which the OM source was
The RMS residuals in the fit of the OM source with the USNO
Catalog, in arcseconds.
The OM source count rate, in ct/s.
The error in the OM source count rate, in ct/s.
The significance of the OM source detection.
The magnitude band of the filter in which the OM source
was detected: V, B, U, UVW1, UVM2, UVW2, or WHITE. The properties
of the OM filters are given in Table 2 of the reference paper.
The measured magnitude of the OM source in the particular band
in which it was observed, derived from the observed count rate and
the particular filter properties in the standard way.
The error in the meassured magnitude of the OM source in the
particular band in which it was observed.
The semi-major axis of the OM source, if extended,
The semi-minor axis of the OM source, if extended,
The position angle of the major axis of the OM source,
if extended, in degrees.
This flag parameter (called Q_FLAG in the reference paper)
is set to 0 for OM sources with good data quality. The following
positive values are used to flag compromised source quality (notice
that they can be used additively):
1 = bad pixel
2 = source on possible read-out streak
4 = source on possible smoke ring
8 = source on possible star diffraction spike
16 = source likely affect by mod-8 pattern
32 = source near bright source
64 = source within central enhanced region
This flag parameter (called C_FLAG in the reference paper)
is set to 0 for OM sources which are unconfused. The following
positive values are used to flag different types of confusion (notice
that they can be used additively):
1 = one or more sources lie within a radius of 6 to 1 unbinned pixels
2 = one or more sources lie within a radius of 6 unbinned pixels
4 = source near an image edge
8 = point source lies partly or entirely within an extended source region
This flag parameter (called E_FLAG in the reference paper)
is set to 0 for OM sources which are non-extended, and to 1 for
Questions regarding the XMMOMOBJ 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