XMM-OM Serendipitous Ultraviolet Source Survey catalogue: SUSS3
The catalogue was compiled for the Optical Monitor instrument on board the ESA XMM Newton observatory. This version, the 3rd release of the catalogue, spans the period of observations from 2000 to July 2015.
In addition to covering a larger observation period, the third release differs from the previous one in the implementation of a new time dependent sensitivity degradation correction. Also the photometry of sources detected on stacked images has been improved and furthermore, these sources are now properly flagged.
All data have been fully processed at the European Space Astronomy Centre (ESAC, Madrid, Spain) by using the XMM Science Analysis Software (SAS) system version 15.0.
The number of observations (OBSIDs) included in the catalogue is 7,886.
The total number of entries in this release is 6,880,116. They correspond to 4,751,899 sources, of which 867,022 have multiple entries in the source table, corresponding to different observations.
The Catalogue consists of two tables. The first one contains the sources, with positional and photometric data (count rate, magnitude and flux) and quality flags for each measurement. In the second table we give a summary of the observations from which the sources have been detected and measured.
The meaning of the quality flags (columns filter_QUALITY_FLAG and filter_QUALITY_FLAG_ST) are as follows:
bit 1 (value 2): source on a readout streak
bit 2 (value 4): source on a smoke-ring
bit 3 (value 8): source on a diffraction spike
bit 4 (value 16): source affected by Mod-8 pattern
bit 5 (value 32): source within the central enhancement
bit 6 (value 64): source near a bright source
bit 7 (value 128): source near the edge
bit 8 (value 256): point source within an extended source
bit 9 (value 512): weird source (bright pixel)
bit 10 (value 1024): multiple exposure values within photometry aperture
bit 11 (value 2048): the source is too bright (rate > 0.97 c/frame)
The columns filter_SKY_IMAGE indicate if a source has been detected in stacked (sky) images obtained with that filter.
The XSA provides access to the OM Catalogue as a complete download of the file (~1 Gb, compressed fits format) as well as through a search interface whose results can be stored by the user in several formats. It should be noted that this interface allows the user to access only part of the information contained in the catalogue: source coordinates, magnitude and flux and their corresponding errors and quality flags. A reduced version of the complete catalogue (500 Mb, compressed fits format) can be downloaded as well.
The ESA-Sky utility allows the user to display the sources from the catalogue on top of sky images from different instruments at all wavelengths. This includes also images obtained with OM in two color combination, Visible (U, B and V OM filters) and UV (UVW1, UVM2 and UVW2 OM filters). It should be noted that OM images have a low dynamic range.