3.1.8. Data: read response file and spectrum¶
3.1.8.1. Overview¶
In order to fit an observed spectrum, SPEX needs a spectral data file and a response matrix. These data are stored in FITS format, tailored for SPEX (see section Response formats). The data files need not necessarily be located in the same directory, one can also give a pathname plus filename in this command.
Warning
Filenames should be entered in the data command without their extension. For the files response.res and spectrum.spo, the data command would look like: data response spectrum.
3.1.8.2. Syntax¶
The following syntax rules apply:
data #a1 #a2
: Read response matrix #a1 and spectrum #a2data delete instrument #i
: Remove instrument #i from the data setdata merge sum #i:
: Merge instruments in range #i: to a single
spectrum and response matrix, by adding the data and matricesdata merge aver #i:
: Merge instruments in range #i: to a single
spectrum and response matrix, by averaging the data and matricesdata save #i #a [overwrite]
: Save data #a from instrument #i with
the option to overwrite the existent file. SPEX automatically tags the
.spo extension to the given file name. No response file is saved.data show
: Shows the data input given, as well as the count
(rates) for source and background, the energy range for which there is
data the response groups and data channels. Also the integration time
and the standard plotting options are given.3.1.8.3. Examples¶
data mosresp mosspec
: read a spectral response file named
mosresp.res and the corresponding spectral file mosspec.spo. Hint,
although 2 different names are used here for ease of understanding, it
is eased if the spectrum and response file have the same name, with
the appropriate extension.data delete instrument 1
: delete the first instrumentdata merge aver 3:5
: merge instruments 3–5 into a single new
instrument 3 (replacing the old instrument 3), by averaging the
spectra. Spectra 3–5 could be spectra taken with the same instrument
at different epochs.data merge sum 1:2
: add spectra of instruments 1–2 into a single
new instrument 1 (replacing the old instrument 1), by adding the
spectra. Useful for example in combining XMM-Newton MOS1 and MOS2
spectra.data save 1 mydata
: Saves the data from instrument 1 in the
working directory under the filename of mydata.spodata /mydir/data/mosresp /mydir/data/mosspec
: read the spectrum
and response from the directory /mydir/data/