XMM-Newton Science Analysis System


rgssources (rgssources-6.3.3) [xmmsas_20230412_1735-21.0.0]

Output Files

1. RGS sources set with a binary extension table named SRCLIST. The header has all the keywords mandatory for PPS products, in particular
   • RA_PNT: The right ascension of the attitude in decimal degrees.
   • DEC_PNT: The declination of the attitude in decimal degrees.
   • PA_PNT: The position angle of the attitude in decimal degrees.

   The SRCLIST table has the following keywords:

   • PRIMESRC: The INDEX value (see column description below) of the prime source.
   • E_EXPRn: There are n ($\le 99$) occurrences of this keyword, one for each EPIC source list added to the RGS list. The numbers n are consecutive, starting at 1. The values of these keywords are taken from the INSTRUME header keyword in the input EPIC source list (that is, probably EPN, in most of the cases, which does not carry a lot of practical meaning, in fact), although it used to be the exposure IDs of the respective EPIC source files (in the old-style source lists).
   • E_CONTn: Similar to the E_EXPRn keyword, but this records the value of the CONTENT keyword in the EPIC file header.
   • E_mBNDn: Similar to the E_EXPRn keyword, but this records the value of either ID_BAND (in the input RGS source file, when filemode=`modify') or bandids, which is used to select the EPIC sources and to calculate the RATE value, transmitted into the output RGS source list. Note that this used to be E_BANDn(=2) before Ver.6.0. If filemode=`modify' and if the input RGS source list has E_BANDn keywords, then they will be preserved in the output RGS source list (i.e., both E_BANDn and E_mBNDn keywords may appear).
   • E_FILTn: Similar to the E_EXPRn keyword, but this records the value of the FILTER keyword in the EPIC file header.

   The SRCLIST table has the following columns:

   Column name:	Data type:	Description:
   INDEX	int16	Source index number. Each source has a unique value, which rgssources never alters.
   LABEL	string	Label for the source. These values are also unique to each source. Only upper case is used. At present, label values can only be 20 characters or less in length. Trailing spaces are not allowed.
   RA	real32	J2000 right ascension in decimal degrees.
   DEC	real32	J2000 declination in decimal degrees.
   RATE	real32	Counts per second.
   DELTA_DISP	real32	Offset on the sky, in the dispersion direction, of the source with respect to the pointing direction. Given in arcminutes.
   DELTA_XDSP	real32	Offset on the sky, in the cross-dispersion direction, of the source with respect to the pointing direction. Given in arcminutes.
   FOV_PHI	real32	This and the next column give the polar coordinates of DELTA_DISP and FOV_PHI. Units for both are decimal degrees. FOV_PHI is the angle of the source position from the -ve dispersion axis towards the +ve cross-dispersion axis.
   FOV_R	real32
   CONFUSION	real32	This is a measure of how confused the source is with respect to the prime source. See subsection 5.2 for a description of how it is calculated. It is a dimensionless number.
   PROCESS	bool	This column is used by rgsregions to flag those sources for which spectrum extraction regions should be calculated. This column is no longer set by rgssources, though, so all values are written as false in principle. An exception is the case of filemode=`modify'; in that case the PROCESS column in the input RGS source list is in principle preserved. Another exception is the sources added by the user (addusersource=true), where the value of the command-line option process is written as it is in principle. In any case, if filemode=`modify' and changeattitude=true, all PROCESS values are forcibly written as false regardless of the value process or PROCESS in the input RGS source list.
   BKG_EXCLUDE	bool	This column is used by rgsregions to flag those sources which should be excluded from the background spectrum extraction region. This column is no longer set by rgssources, so all values are written as false.
   FIXED_ON_SKY	bool	This column flags those sources for which the positional information was derived from right ascension and declination. The only sources for which FIXED_ON_SKY is false are the attitude source and any user source supplied with userstyle=`wtatt'.

   Column name:	Data type:	Description:
   EPIC_FILE	int16	This gives the number of the E_EXPRn, E_CONTn, E_mBNDn (or E_BANDn before Ver.6.0) and E_FILTn keywords appropriate to the source if it has been derived from an EPIC source list. Eg, for EPIC_FILE=3, the details of the original list from which this source came can be found from the keywords E_EXPR3, E_CONT3, E_mBND3 and E_FILT3.
   FLAG	int32	If non-zero, something goes wrong in the source. It is a binary (bit-type) form of representation for each cause – see the following table for detail (n.b., The representation of this FLAG column is entirely different from that in the input EPIC source list). Note that some of the checks may be bypassed if requested (by command-line parameters); for example if enablefilter=false and flagepicsrcoutoffov=false, no check for OUTOFFOV is carried out.

   The following is the description for the FLAG column:

   Name	Bit	Description
   OUTOFFOV	0	The source is out of field of view.
   CONFUSED	1	The source may be confused with other source(s).
   BADBAND	2	The energy band used (hence RATE) may be wrong.
   WIDESRC	3	The source is greater than 90 degrees away from the pointing.

   Note that the RGS source list set is also used to store the spectrum extraction regions created by rgsregions. These become invalidated if the attitude is altered; in this case rgssources deletes them. See the algorithm (section 7) for details of the circumstances under which this occurs.

   The RGS source list table is required to have 1 source whose position is taken from the observation proposal, and 1 source whose position is equal to the RGS attitude (stored in the dataset header keywords RA_PNT, DEC_PNT and PA_PNT). The LABEL values of these two sources are PROPOSAL and ONAXIS respectively.