NAME

ftmarfrmf -- multiplies/divides a detector redistribution matrix by an ancillary response dataset or a scalar

USAGE

ftmarfrmf rmffile[ext#] (ebdfile[ext#]) arffile[ext#] outfile (rmfversn) (qoverride) telescop instrume filter detnam (clobber) scalar (qdivide) (arfcol)

DESCRIPTION

A detector redistribution matrix (aka response matrix) basically consists of a 2-dimensional array (detector channel vs incident photon energy) giving the probability that an incident photon of a given energy will be detected in a given detector channel. An ancillary response dataset is a 1-dimensional array as a function of incident photon energy (containing, for example, the effective area of the optics, corrections for the spatial point spread function etc). Provided the input files are in the standard RMF FITS format, this task multiplies the redistribution array for each channel (along the incident energy dimension) by the ancillary response array (ARF). The output is thus a new RMF file containing the new redistribution matrix.

A detailed description of the RMF file can be found at: https://heasarc.gsfc.nasa.gov/docs/heasarc/caldb/docs/memos/cal_gen_92_002/cal_gen_92_002.html In brief, the output file consists of a FITS file with 2 BINTABLE extensions (both of which have HDUCLAS1 = RESPONSE), containing:

(1) the redistribution matrix (with HDUCLAS2 = RSP_MATRIX)
(2) the nominal energies of the channel boundaries (with HDUCLAS2 = EBOUNDS)

The data contained in Extension (1) above is in a compressed format whereby only elements for which the value of the redistribution matrix above a given threshold are stored. This provides a significant reduction in disk-storage requirements for sparsely populated matrices. The default threshold is read from the input file. Users are reminded that the threshold is defined in absolute units (NOT relative to the value of the maximum value in the matrix).

PARAMETERS

rmffile [filename]
The name of the RMF file containing the input redistribution matrix. If there are multiple matrix extensions then they will all be multiplied by the ARF (or scalar value). If the number of energy bins in the ARF is a multiple of the number of energy bins in one of the matrix extensions (as will happen for XRISM Resolve RMFs) then the ARF is binned up to multiply that matrix.

(ebdfile = '%') [string]
The name of the file containing the i/p EBOUNDS dataset Since the EBOUNDS extension corresponding to a given RSP_MATRIX usually resides in the same file as the RSP_MATRIX, this parameter is hidden with the default value "ebdfile = %" indicating that the rmffile will be used.

arffile [filename]
The name of the ARF file containing the ancillary spectral response dataset with which the i/p redistribution matrix is to be multiplied/divided. If a value of 'NONE', 'none' or ' ' is entered the user will be prompted for the scalar value by which the the i/p redistribution dataset is to be multiplied/divided.

outfile [filename]
The name of the RMF file to be created. For safety, the name of the output file cannot be the same as one of the input files, and the task will stop if this is the case. However, the existing file can be automatically removed, and the new file written if the output filename is preceeded by "!" at the outfile prompt.

(rmfversn) [string]
The OGIP FITS format version for RMF files in which the output FITS is to be written. This parameter is obsolete and is not used.

(qoverride = no) [boolean]
Logical indicating whether the user wishes to override the mission and instrument strings in the input file. The default is QOVERRIDE=N

telescop [string]
The user-supplied string for the telescope name, required if QOVERRIDE=Y

instrume [string]
The user-supplied string for the instrument name, required if QOVERRIDE=Y

filter [string]
The user-supplied string for the name of any moveable filter in use, required if QOVERRIDE=Y. FILTER=NONE should be used if on such moveable filter is in use.

detnam [string]
The user-supplied string for the sub-instrument name, required if QOVERRIDE=Y. DETNAM=NONE should be used if the specification of a sub-instrument is unneccessary.

(clobber = false) [boolean]
Flag specifying whether or not a pre-existing file with the same name as that requested as the output file from this task will be overwritten.

scalar [real]
Scalar value by which the RSP_MATRIX dataset is divided or multiplied. This parameter is only used when arffile = 'NONE', 'none' or ' ' is entered.

(qdivide = no) [boolean]
Flag to indicate whether the RSP_MATRIX dataset is DIVIDED (qdivide = yes) or MULTIPLIED (qdivide = no) by the SPECRESP dataset/scalar.

(arfcol = 'SPECRESP') [string]
The column name to use to read the ARF data. SPECRESP is the standard but this parameter allows another column to be read if necessary.

EXAMPLES

ftmarfrmf test.rmf test.arf test.rsp

LAST MODIFIED

February 2025