niextspect - extract standard NICER spectrum from event file


niextspect infile outfile


The niextspect task extracts a standard NICER spectrum from a NICER event file. It reproduces the steps that can be performed within XSELECT using

extract spectrum
but programmatically from the command line.

The input is a NICER event file. Additionally the user can specify a timefile (i.e. GTI file) for further temporal filtering.


infile [filename]
NICER input event file. It is allowed to specify a list of event files using the @filenames.lis style of input.
outfile [filename]
Name of output spectrum file.
(timefile = "NONE") [string]
The name of a temporal good time interval file, or NONE for no temporal filtering. Note that there is no 'gtinam' parameter; you should specify the extension name directly in the timefile parameter, for example as "timefile='mytime.gti[STDGTI]'".
(pirange="0:1500") [string]
Range of PI values to consider, in the form "start:stop" where the bin numbers are inclusive. For almost all NICER spectra, use "0:1500". Either low:high or low-high notation is allowed.
(filters="NONE") [string]
A comma-separated list of extractor interval filters to be additionally applied to the data. Please see the help for extractor for more information.
(spectbin=1) [integer]
Spectral rebinning factor. It is not recommended to change this from a value of 1. If rebinning is desired, please use ftgrouppha instead.
(gti = "GTI") [string]
The name of the GTI extension in the input event files, which is "GTI" for NICER.
(events = "EVENTS") [string]
The name of the EVENTS extension in the input files.
(ecol = "PI") [string]
The name of the column used for the pulse height of the event, typically PI but possibly PHA.
(tcol = "TIME") [string]
The name of the column used for the time of the event.
(cleanup="YES") [boolean]
If yes, then clean up temporary files. If no, temporary files remain. This is typically for debugging.
(clobber = NO) [boolean]
If the output file already exists, then setting "clobber = yes" will cause it to be overwritten.
(chatter = 2) [integer, 0 - 5]
Controls the amount of informative text written to standard output. Setting chatter = 4 or higher will produce detailed diagnostic output; chatter = 1 prints out a basic diagnostic message. The default is to produce a brief summary on output.
(history = YES) [boolean]
If history = YES, then a set of HISTORY keywords will be written to the header of the specified HDU in the output file to record the value of all the niextspect task parameters that were used to produce the output file.


Run niextspect for myfile.evt and place the output in myspectrum.pha.

   niextspect myfile.evt myspectrum.pha









Jul 2022