XMM-OM Serendipitous Ultraviolet Source Survey catalogue: SUSS4.1

SUSS4.1 is a new 2018 release of the XMM OM Serendipitous Ultraviolet Source Survey catalogue. This new release corrects some inconsistencies between IAUNAME and SRCNUM found in the previous release (OM SUSS4).

The catalogue was compiled for the Optical Monitor instrument on board the ESA XMM Newton observatory. This version, the 4^th release of the catalogue, spans the period of observations from 2000 to July 2017.

A detailed description of the Catalogue can be found here. A refereed paper on the first version can be found in Page M.J. et al. (2012).

In addition to covering a larger observation period, the fourth release differs from the previous one in the implementation of a new time dependent sensitivity degradation correction. As in the previous release, sources detected on stacked images are 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 17.0.

The number of observations (OBSIDs) included in the catalogue is 9,749.
The total number of entries in this release is 8,176,156. They correspond to 5,503,765 sources, of which 1,035,453 have multiple entries in the source table, corresponding to different observations.

The Catalogue consists of two tables. The first one (SRCLIST) contains the sources, with positional and photometric data (count rate, magnitude and flux) and quality flags for each measurement. The content of the different columns (114) is:

In the second table (SUMMARY) we give a summary of the observations from which the sources have been detected and measured. The content of the columns (35) in this table is: 

The meaning of the quality flags (columns filter_QUALITY_FLAG and filter_QUALITY_FLAG_ST) in the SRCLIST table are as follows:

The columns filter_SKY_IMAGE indicate if a source has been detected in stacked (sky) images obtained with that filter. The catalogue contains 948,277 such detections, with 60,889 sources having multiple detections in different observations.

A cross-match of the whole catalogue with GAIA DR2 data set, using a search radius of 3 arcsec gives 82% matches. Detections in the V filter have 89% matches.

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.