Summary release note for ppsprod-18.01
======================================

Pipeline Version: 18.01_20200110_1700
Pipeline name: ppsprod
Release Date: 2020-01-10
SAS Manifest: xmmsas_20191120_1210



Summary
=======
This version of the pipeline is basically the one used to reprocess
all archival data available up to 2019. The few changes in SAS
routines versions only reflect the upgrade to public SAS18 version.

Since the reprocessed observaions public before April 2019 have been
used for a major version of the EPIC Serendipitous Source Catalogue
(SSC), the changes outlined below refer to the pipeline used for
previous major version of the SSC catalogue, some of them were already
introduced in previous pipeline versions.  Improvements in
calibrations are not listed here as they can be found in SAS and/or
CCFs release notes.

i) Extraction of source-specific products (SSP) (time-series and
spectra) for individual sources has undergone a major revision.  The
size of the source extraction region is still optimized according to
the brightness of the source, but the region to estimate the
associated background is now restricted to the same CCD where the
center of the source is found, except for MOS SW modes, where an
annulus over the peripheral CCDs is chosen. PNG files with source and
background extraction regions overlaid on count images are also new
SSP products.

In the case of EPIC-pn Timing mode data the location of the source 
in RAWX coordinate is determined as the 
location of maximum of the RAWX histogram. The source extraction region 
extends 9 RAWX columns on side of the source location and the 
background region is fixed to RAWX in [2,6]. If the source and background 
extraction regions are found to overlap or there are less than 100 counts 
in the histogram, the source products are not created. In the case of 
very strong spectra this method may produce a background with significant 
contribution of the source at certain energies. 

ii) EPIC lightcurves are produced per energy band for all exposures. 
A new FITS file is available under the PPS products per EPIC instrument
and observation which contains lightcurves for all the available 
exposures in the energy bands 1, 2, 3, 4, 5 and 8. For TIMING mode 
information is given in the energy bands 2, 3, 4 and 9. 
The time bin size for PN Light Curves has been fixed to 20 times
the frametime of the corresponding exposure mode. For MOS1/2 the
method to fix the time bin size according the mean count rate has
not been modified. Given the low count number per bin in most EPIC-pn 
lightcurves the variability tests are computed on lightcurves rebinned
to an average of 20 counts per bin and the results of the tests are 
saved in the header of the small time bin PPS product.

iii) The method to estimate the background in EPIC images has been 
changed from splines interpolation to local smoothing of source free
regions. The new method in combination of an extra call to embadpixfind
task yield a reasonable compromise between detection number and spurious
content. 

iv) Special flagging has been included for sources detected in OM low
sensitivity patch.

v) Quiescent particle background (estimated from Filter-Wheel-Closed 
repository) and EPIC-pn out of time events are subtracted from EPIC 
coloured images.

Other minor changes related to general info about observations
environment are

a) new PPS file with spacecraft orbit information as Geocentric Equatorial 
J2000 and Geocentric Solar Ecliptic coordinates

b) new PPS file with Radiation Monitor count rates


The version of SAS being used is a pipeline-specific manifest
xmmsas_20191120_1210. This is based on the public SAS release 18.0.0,
described at
http://www.cosmos.esa.int/web/xmm-newton/sas-release-notes-1800



Documentation
=============

Documentation for this pipeline can be found at:

http://www.cosmos.esa.int/web/xmm-newton/pipeline

and links therein.