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Дата изменения: Wed May 30 01:10:14 2001 Дата индексирования: Tue Oct 2 05:55:02 2012 Кодировка: Поисковые слова: mercury program |
MKRMF generates a response matrix for an arbitrary redistribution function over a 2-dimensional grid plane. Since last reported by He (1999) it has evolved to include:
The tool's parameter file (mkrmf.par) has been accordingly updated, as listed in Table 1. The table highlights the most important parameters.
![\begin{deluxetable}{l@{\extracolsep{\fill}}l@{}l}
\scriptsize\tablecaption{Binni...
...in FITS format&\verb*+[cols ENERG_LO, ENERG_HI)])+\nl
\enddata
\end{deluxetable}](img2.gif)
MKRMF always computes the matrix (and EBOUNDS) at full resolution at the specified
<min>:<max> range. The matrix can be binned by specifying
bin type and step size. MKRMF will use this information to scale down the output
to the requested bin size.
MKRMF takes the analytic redistribution functions which are conventionally
expressed by columns of independent function variables.
These function variable columns are stored in the
FEF format and used by MKRMF to create standard response matrices.
Prior to the release of CIAO 2.0, a FEF file existed for each
individual spatial
region for which (different) redistribution functions were defined.
Because of this, those who wished to perform analyses over large spatial
regions or over multiple chips potentially had to keep track of a large
number of files. In CIAO 2.0, these files have been merged into a single
file, an all-inclusive and spatial varying FEF file.
In addition to columns containing redistribution function parameter
values, the new FEF file contains new columns CCD_
ID, CHIPX, and CHIPY, which provide the location and bounds for each spatial region.
Another new column, REGNUM, contains an integer value that identifies
each spatial region uniquely. The new FEF format also encapsulates
the gain relationship of the CCD for energy in a specific
region. This relationship is defined by a new column, CHANNEL
(or PHA), mapped to ENERGY in that region.
By introducing the ( ENERGY, CHANNEL) pair columns,
the generic FEF extractor can effectively result
in data block consisting of one region for each energy when a
DM filter is applied to the FEF file. Therefore, the generic FEF
file is effectively reusable and backward compatible.
The MKRMF user must now use DM syntax to retrieve information for one spatial region, as shown in this example:
mkrmf infile=fef.fits[ccd_id=7, chipx=(1:100),chipy=(1:32)]
When mkrmf executes the program with an input FEF file named
"fef.fits", it extracts the data containing ( ENERGY,
CHANNEL) gain and redistribution function variables internally sorted
for CCD_ ID of 7 with chip pixel range of 1 to 100
and 1 to 32 along X- and Y-Axis, respectively.
Figure 1 illustrates two MATRIX components generated on
a FEF file with the filter above for a combination of ten embedded
Gaussian functions on linear binned PHA-energy grids.
The CHANNEL and ENERGY pairs in the new FEF file encapsulate the piecewise linear gain information within a given ( CHIPX, CHIPY) region for each specific energy value. Our new scheme to calculate the EBOUNDS array is to linearly interpolate the energy for a given PHA value from the pairs of channel and corresponding energies that bound the PHA value. The EBOUNDS energy derived in this way represents the variation of the CCD gain in that region, or an effectively non-linear and spatial varying relationship.
He, H. Wise, M., & Ljungberg, M. 1999, in ASP Conf. Ser., Vol. 216, Astronomical Data Analysis Software and Systems IX, ed. N. Manset, C. Veillet, & D. Crabtree (San Francisco: ASP), 636
Rots, A. H. 2001, this volume, 479
