Using specextract to Extract ACIS Spectra and Response Files for Extended Sources
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CIAO 4.1 Science Threads
OverviewLast Update: 17 Feb 2009 - added "for Extended Sources" to the title Synopsis: specextract is a script for creating ACIS spectra for extended sources. It allows the user to create source and background PHA or PI spectra and the associated ARF and RMF files. specextract can take a stack of input files and generate many spectra in one run of the script. Read the help file for full details on how the script works. The mkwarf tool, which is used for ARF generation by specextract, may not produce accurate results for point sources. For point source extraction, the psextract script is recommended. This script is designed to replace the acisspec script currently distributed in the CIAO Scripts package. The major improvement over its predecessor is the ability to determine when mkacisrmf should be used in place of mkrmf (see the "Creating RMFs: mkrmf vs. mkacisrmf" section of this thread). Users are encouraged to start using specextract in place of acisspec for new extended source analyses. Note that specextract does not currently offer the option to coadd spectra as acisspec does. Purpose: To generate source and background PI (PHA) spectra of an extended ACIS source and build the proper RMFs and ARFs. Read this thread if: you are working with an ACIS observation of an extended source, whether imaging or grating data. |
Contents
- How specextract Works
- Get Started
- Single Spectrum
- Extracting Multiple Spectra
- More Information on the Output Files
- Running mkacisrmf Independently
- Fitting
- Caveats
- Parameter files:
- History
- Images
How specextract Works
specextract runs the dmextract, mkwarf, mkrmf or mkacisrmf (see the "Creating RMFs: mkrmf vs. mkacisrmf" section), dmgroup and dmhedit tools.
- dmextract: to extract source and (optionally) background spectra. This tool also creates the WMAP used as input to mkwarf and mkacisrmf; see ahelp mkwarf for details on why a WMAP is necessary.
- mkwarf: to create weighted ARF(s).
- mkrmf or mkacisrmf: to build the RMF(s); also see the "Creating RMFs: mkrmf vs. mkacisrmf" section.
- dmgroup: to group the source spectrum and/or background spectrum.
- dmhedit: to update the BACKFILE, RESPFILE and ANCRFILE keys in the source and background spectrum files.
ACIS CTI_APP Keyword Required
CIAO 4.1 and CALDB 4.1 require that ACIS event files have a CTI_APP header keyword to indicate whether the CTI correction has been applied. The older CTI_CORR keyword is no longer used.
To check for CTI_APP:
unix% dmkeypar input.fits CTI_APP echo+ # dmkeypar (CIAO 4.1): ERROR: Keyword 'CTI_APP' was not found in file 'input.fits'.
If CTI_APP is not found, follow the instructions in the ACIS CTI_APP Keyword Required section of the ACIS CTI Correction why topic to add the keyword before continuing.
This thread may produce incorrect results without issuing an error if the keyword is missing.
Creating RMFs: mkrmf vs mkacisrmf
The tool mkacisrmf is used to create RMFs for:
- all -120 ACIS data taken in (V)FAINT mode that has the time-dependent gain adjustment and CTI correction applied
- -120 ACIS GRADED mode data on the back-illuminated chips (ACIS-S1 and S3) only
- -110 ACIS data taken on the back-illuminated chips (ACIS-S1 and S3) only
All new analyses with these types of data should be done with mkacisrmf instead of mkrmf.
It is important that the calibration applied to the event file is consistent with the RMF tool chosen, as explained in the "Using Consistent Calibration" section of the why topic. If necessary, reprocess your data with the correct gain file before beginning this thread.
How specextract chooses the RMF tool to use
specextract reads the source and background file header keywords to determine when the observation was taken and what calibration has been applied. The script then does a CALDB lookup to compare the calibration applied to the event file and the most recent file available in the CALDB. This means that the data needs to have been processed with very newest calibration, not just a "good enough" version; that is, even if the new calibration will have a minimal effect on your data, specextract requires that it be applied for the "use mkacisrmf" switch to be triggered.
If all the requirements are met, the script uses mkacisrmf to generate the source and background RMF(s) for the data. If the observation was not done at -120 or has not been reprocessed with the newest calibration available, specextract creates the RMF(s) with mkrmf. At higher verbosities, a message of this form will be printed to the screen:
Cannot use mkacisrmf because last applied gainfile does not match current CALDB gainfile: acisD2000-01-29gain_ctiN0004.fits != acisD2000-01-29gain_ctiN0006.fits Please re-run <your_filename> with acis_process_events if you wish to use mkacisrmf
Users who don't wish to reprocess can still use specextract, and run mkacisrmf afterwards to create new RMF files.
The ACIS dead area correction
In CIAO 4.0, the application of the dead area correction is turned on by default. The pbkfile and dafile parameters were added to the script in order to apply the calibration. The thread includes the correction when running specextract.
The "dead area" is a fractional area loss per unit time due to cosmic ray flux incident on the ACIS detector. Calibration to account for this ACIS "dead area" was included in CALDB 3.3.0 on 15 December 2006. The correction is non-zero for the 8 front-illuminated (FI) ACIS chips; the effect is not detectable for the back-illuminated (BI) chips, so there is no correction applied to them.
Refer to the ACIS Dead Area Correction why topic for more information, including how to "turn off" the correction, e.g. if you would like to compare results with and without it applied.
Get Started
Sample ObsIDs used: 869 (ACIS-S, ARP 220); 1842 (ACIS-I, G21.5-09); 1843 (ACIS-I, G21.5-09)
File types needed: evt2; pbk0
Please ensure that you have set up ardlib to use the bad pixel file for your observation before following this thread.
One of the event files used in this thread - acis_869_evt2.fits - has been reprocessed with the newest calibration available by following the Create a New Level=2 Event File thread.
Choosing a background file
There are several options when choosing the background file for use with specextract:
- define the background region from a source-free region of the same event file
- use a different event file when defining the background
- omit the background completely (i.e. leave the bkgfile blank)
If you plan on using one of the "blank-sky" background files from the CALDB with specextract, read the Using the ACIS "Blank-Sky" Background Files caveats before continuing.
Single Spectrum
A simple example: extracting spectra with one source region and one background region.
Build Source and Background Regions
We need to define two regions, one for the source and another for the background. To do this, first display the file:
unix% ds9 acis_869_evt2.fits &
Refer to the Using CIAO Regions thread for information on creating region files. The files for this example look like:
unix% cat simple.reg # Region file format: CIAO version 1.0 ellipse(4026,4138.9,50,40,0) unix% cat bg_simple.reg # Region file format: CIAO version 1.0 circle(3975,4233,20)
The regions are shown displayed on the event file in Figure 1; the source is white and the background is green.
Make sure that you save the regions in CIAO format (Regions → File Format → CIAO) so that they are fully compatible with the analysis tools.
![[Thumbnail image: The source region and the background region are each a single ellipse.]](single.png)
[Version: full-size]
Figure 1: Extraction regions on the event file
The background was chosen from a from source-free area of the same chip for this example, but it may also be chosen from a different chip or different event file.
Run specextract
Input the event file with the appropriate region file for the source and background:
unix% punlearn specextract unix% pset specextract infile="acis_869_evt2.fits[sky=region(simple.reg)]" unix% pset specextract outroot=simple unix% pset specextract bkgfile="acis_869_evt2.fits[sky=region(bg_simple.reg)]" unix% pset specextract pbkfile=acisf078247287N003_pbk0.fits unix% pset specextract grouptype=NUM_CTS binspec=15
We choose to use the default grouping values: the source spectrum will be grouped to a minimum number of 15 counts per new channel and the background spectrum will be ungrouped. The grouptype and binspec parameters are used to specify the source spectrum grouping, and the bkg_grouptype and bkg_binspec parameters specify the background spectrum grouping.
Running the tool with verbose=1 shows what it is doing:
unix% specextract verbose=1
Source events file(s) (acis_869_evt2.fits[sky=region(simple.reg)]):
Output directory path + root name for output files (simple):
pbkfile input to mkwarf (acisf078247287N003_pbk0.fits):
Running: specextract
Checking initial status and initializing variables...
Extracting src spectra for item 1 of 1 in input list
----------------------------------------------------------------------
Input Parameters
----------------------------------------------------------------------
VERBOSE: infile = acis_869_evt2.fits[sky=region(simple.reg)][bin PI]
VERBOSE: outfile = simple.pi
VERBOSE: Creating output file simple.pi
VERBOSE: Write WMAP using acis_869_evt2.fits[sky=region(simple.reg)][energy=300:2000][bin det=8]
Creating src ARF for item 1 of 1 in input list
Parameters for mkwarf:
infile = simple.pi[WMAP]
outfile = simple.warf
weightfile = simple.wfef
feffile = CALDB
egridspec = 0.3:11.0:0.01
spectrumfile =
threshold = 0
mirror = HRMA
ardlibpar = ardlib
clobber = no
verbose = 1
Creating src RMF for item 1 of 1 in input list
Using mkacisrmf...
*** mkacisrmf parameter inputs ***
input file: CALDB
output file: simple.wrmf
wmap file: simple.pi[WMAP]
energy: 0.3:11.0:0.01
channel: 1:1024:1
chantype: PI
ccd_id:
chipx:
chipy:
contour lvl: 100
log file:
gain file: CALDB
asolfile:
obsfile: simple.pi[WMAP]
pixlib param. file: geom
threshold: 1.00e-06
clobber(1=yes, 0=no): 0
verbose level: 1
WARNING: Did not find 'GRATTYPE' in supplied header, skipping it
WARNING: Did not find 'CCD_ID' in supplied header, skipping it
CALDB -> /soft/ciao/CALDB/data/chandra/acis/p2_resp/acisD2000-01-29p2_respN0006.fits
WARNING: Did not find 'GRATTYPE' in supplied header, skipping it
CALDB -> /soft/ciao/CALDB/data/chandra/acis/det_gain/acisD2000-01-29gain_ctiN0006.fits
Total 17 regions to be processed:
1> reg# 1263 processed
2> reg# 1264 processed
3> reg# 1265 processed
4> reg# 1266 processed
5> reg# 1295 processed
6> reg# 1296 processed
7> reg# 1297 processed
8> reg# 1298 processed
9> reg# 1327 processed
10> reg# 1328 processed
11> reg# 1329 processed
12> reg# 1330 processed
13> reg# 1359 processed
14> reg# 1360 processed
15> reg# 1361 processed
16> reg# 1362 processed
17> reg# 1392 processed
Grouping src spectrum for item 1 of 1 in input list
Parameters for dmgroup:
infile = simple.pi[SPECTRUM]
outfile = simple_grp.pi
grouptype= NUM_CTS
xcolumn = channel
binspec =
ycolumn = counts
tabspec =
tabcolumn=
stopspec=
stopcolumn=
errcolumn=
grouptypeval= 15.000000
maxlength= 0.000000
clobber = no
verbose = 1
Updating header of simple.pi with RESPFILE and ANCRFILE keywords.
dmhedit: verbose set to 1
dmhedit: Input file = simple.pi
dmhedit: file list = none
dmhedit: key RESPFILE will be added.
dmhedit: verbose set to 1
dmhedit: Input file = simple.pi
dmhedit: file list = none
dmhedit: key ANCRFILE will be added.
Updating header of simple_grp.pi with RESPFILE and ANCRFILE keywords.
dmhedit: verbose set to 1
dmhedit: Input file = simple_grp.pi
dmhedit: file list = none
dmhedit: key RESPFILE will be added.
dmhedit: verbose set to 1
dmhedit: Input file = simple_grp.pi
dmhedit: file list = none
dmhedit: key ANCRFILE will be added.
Extracting bkg spectra for item 1 of 1 in input list
----------------------------------------------------------------------
Input Parameters
----------------------------------------------------------------------
VERBOSE: infile = acis_869_evt2.fits[sky=region(bg_simple.reg)][bin PI]
VERBOSE: outfile = simple_bkg.pi
VERBOSE: Creating output file simple_bkg.pi
VERBOSE: Write WMAP using acis_869_evt2.fits[sky=region(bg_simple.reg)][energy=300:2000][bin det=8]
Creating bkg ARF for item 1 of 1 in input list
Parameters for mkwarf:
infile = simple_bkg.pi[WMAP]
outfile = simple_bkg.warf
weightfile = simple_bkg.wfef
feffile = CALDB
egridspec = 0.3:11.0:0.01
spectrumfile =
threshold = 0
mirror = HRMA
ardlibpar = ardlib
clobber = no
verbose = 1
Creating bkg RMF for item 1 of 1 in input list
Using mkacisrmf...
*** mkacisrmf parameter inputs ***
input file: CALDB
output file: simple_bkg.wrmf
wmap file: simple_bkg.pi[WMAP]
energy: 0.3:11.0:0.01
channel: 1:1024:1
chantype: PI
ccd_id:
chipx:
chipy:
contour lvl: 100
log file:
gain file: CALDB
pixlib param. file: geom
threshold: 1.00e-06
clobber(1=yes, 0=no): 0
verbose level: 1
WARNING: Did not find 'GRATTYPE' in supplied header, skipping it
WARNING: Did not find 'CCD_ID' in supplied header, skipping it
CALDB -> /soft/ciao/CALDB/data/chandra/acis/p2_resp/acisD2000-01-29p2_respN0006.fits
WARNING: Did not find 'GRATTYPE' in supplied header, skipping it
CALDB -> /soft/ciao/CALDB/data/chandra/acis/det_gain/acisD2000-01-29gain_ctiN0006.fits
Total 5 regions to be processed:
1> reg# 1393 processed
2> reg# 1394 processed
3> reg# 1425 processed
4> reg# 1426 processed
5> reg# 1457 processed
Updating header of simple_bkg.pi with RESPFILE and ANCRFILE keywords.
dmhedit: verbose set to 1
dmhedit: Input file = simple_bkg.pi
dmhedit: file list = none
dmhedit: key RESPFILE will be added.
dmhedit: verbose set to 1
dmhedit: Input file = simple_bkg.pi
dmhedit: file list = none
dmhedit: key ANCRFILE will be added.
Updating header of simple.pi with BACKFILE keyword.
dmhedit: verbose set to 1
dmhedit: Input file = simple.pi
dmhedit: file list = none
dmhedit: key BACKFILE will be added.
Updating header of simple_grp.pi with BACKFILE keyword.
dmhedit: verbose set to 1
dmhedit: Input file = simple_grp.pi
dmhedit: file list = none
dmhedit: key BACKFILE will be added.
The contents of the parameter file may be checked with plist specextract.
Examining the Output Files
The number of files created depends on if a background event file was provided and if source and/or background grouping was specified. In this case, the output files are:
Source: simple.pi ungrouped spectrum simple.warf weighted ARF simple.wfef FEF weight file simple.wrmf weighted RMF simple_grp.pi grouped spectrum Background: simple_bkg.pi ungrouped spectrum simple_bkg.warf weighted ARF simple_bkg.wfef FEF weight file simple_bkg.wrmf weighted RMF
The FEF weight files (.wfef) are required as input to mkrmf; they are created by mkwarf before the scripts determines whether to use mkrmf or mkacisrmf. After the RMFs are created, these files are no longer needed.
Extracting Multiple Spectra
In this example, we show how specextract can create multiple output spectra from a single run of the script.
Build Source Regions and Background Regions
This example uses the two observations of G21.5-09. Both observations will be processed by specextract at the same time, producing two sets of output files; this is explained further in the Run specextract section.
We define have defined a source and background region for each observation:
unix% cat 1842_src.reg # Region file format: CIAO version 1.0 circle(2249.5,4221.5,102.0092) unix% cat 1842_bg.reg # Region file format: CIAO version 1.0 circle(2565.5,4129.5,40) unix% cat 1843_src.reg # Region file format: CIAO version 1.0 circle(1635.5,4113.5,135.11408) unix% cat 1843_bg.reg # Region file format: CIAO version 1.0 circle(2129.5,4007.5,40)
The regions are shown displayed on the event files in Figure 2; ObsID 1842 is in the top frame ObsID 1843 is in the bottom frame. The source region is in white and the background region is in green in each frame.
![[Thumbnail image: The two event files used for spectral extraction are displayed in ds9 with the source and background regions overlaid.]](multi.png)
[Version: full-size]
Figure 2: Extraction regions on the event files
ObsID 1842 is displayed in the top frame and ObsID 1843 is displayed in the bottom frame.
Run specextract
The event files are input to the script as a stack; this syntax means that a separate spectrum will be created for each of the file/region pairs:
unix% cat multi_src.lis 1842_evt2.fits[sky=region(1842_src.reg)] 1843_evt2.fits[sky=region(1843_src.reg)]
When working with stack inputs to specextract, the source and background stacks must contain the same number of items, unless you are not extracting background spectra. Make sure that the background file definitions are in the same order as the source files:
unix% cat multi_bg.lis 1842_evt2.fits[sky=region(1842_bg.reg)] 1843_evt2.fits[sky=region(1843_bg.reg)]
When applying the ACIS dead area correction, the same number of parameter block files is also required:
unix% cat multi_pbk.lis acisf084281294N002_pbk0.fits acisf084272477N002_pbk0.fits
Finally, create a stack of output root names:
unix% cat multi_out.lis 1842 1843
If you prefer, you may just give a string as the outroot and specextract will create output files designated as "src1", "src2", "bkg1", "bkg2", etc.
unix% pset specextract outroot=multi
Set the parameters:
unix% punlearn specextract unix% pset specextract infile=@multi_src.lis unix% pset specextract outroot=@multi_out.lis unix% pset specextract bkgfile=@multi_bg.lis unix% pset specextract pbkfile=@multi_pbk.lis unix% pset specextract grouptype=BIN binspec=10
The source spectra will be grouped into bins of 10 channels each.
Note that this method allows you to input as many event file/region file pairs as you like, but the same grouping will be applied to all of them. The tool is run with verbose=0 for no screen output:
unix% specextract Source events file(s) (@multi_src.lis): Output directory path + root name for output files (multi): pbkfile input to mkwarf (@multi_pbk.lis):
The contents of the parameter file may be checked with plist specextract.
Examining the Output Files
The number of files created depends on if a background event file was provided and if source and/or background grouping was specified. In this case, the output files are:
Source 1 (1842_src.reg): 1842.pi ungrouped spectrum 1842.warf weighted ARF 1842.wfef FEF weight file 1842.wrmf weighted RMF 1842_grp.pi grouped spectrum Source 2 (1843_src.reg): 1843.pi 1843.warf 1843.wfef 1843.wrmf 1843_grp.pi Background 1 (1842_bg.reg): 1842_bkg.pi 1842_bkg.warf 1842_bkg.wfef 1842_bkg.wrmf Background 2 (1843_bg.reg): 1843_bkg.pi 1843_bkg.warf 1843_bkg.wfef 1843_bkg.wrmf
If one string is provided for the outroot parameter, the script simply numbers the output to match the order in which the files were input: src1 = 1842_src.reg and src2 = 1843_src.reg. Similarly, the background files are bkg1 and bkg2.
More Information on the Output Files
Which RMF tool was used?
When specextract is run with verbose greater than zero, the status messages printed to the screen report which tool was used to create the RMF, mkacisrmf or mkrmf. This information is also recorded in the FITS file that is created. Use the dmhistory tool to read the file history:
unix% dmhistory simple.wrmf all mkacisrmf infile="CALDB" outfile="simple.wrmf" wmap="simple.pi[WMAP]" energy="0.3:11.0:0.01" channel="1:1024:1" chantype="PI" ccd_id="0" chipx="0" chipy="0" gain="CALDB" asolfile="" obsfile="simple.pi[WMAP]"logfile="" contlvl="100" geompar="geom" thresh="1e-06" clobber="no" verbose="1" unix% dmhistory 1842.wrmf all mkrmf infile="CALDB" outfile="1842.wrmf" axis1="energy=0.3:11.0:0.01" axis2="pi=1:1024:1" logfile="" weights="1842.wfef" thresh="1e-05" outfmt="legacy" clobber="no" verbose="0" axis3="none" axis4="none" axis5="none"
The single spectrum example created the RMF with mkacisrmf, while the multiple spectra example used mkrmf. Refer back to the Creating RMFs section for information on how the script decides which tool to use.
If specextract used mkrmf, but you know the calibration is good enough for mkacisrmf, read the Running mkacisrmf Independently section.
Header keywords
The RESPFILE and ANCRFILE header keywords in the source and background spectra have been updated, as well as the BACKFILE in the source spectra only. For example, in the single source output files:
unix% dmlist simple_grp.pi header | grep FILE 0110 BACKFILE simple_bkg.pi String 0111 CORRFILE none String 0112 RESPFILE simple.wrmf String 0113 ANCRFILE simple.warf String unix% dmlist simple_bkg.pi header | grep FILE 0112 BACKFILE none String 0113 CORRFILE none String 0114 RESPFILE simple_bkg.wrmf String 0115 ANCRFILE simple_bkg.warf String
If stack inputs were used, the source and background file header values are matched up appropriately:
unix% dmlist 1842_grp.pi header |grep FILE 0098 BACKFILE 1842_bkg.pi String 0099 CORRFILE none String 0100 RESPFILE 1842.wrmf String 0101 ANCRFILE 1842.warf String unix% dmlist 1843_grp.pi header |grep FILE 0098 BACKFILE 1843_bkg.pi String 0099 CORRFILE none String 0100 RESPFILE 1843.wrmf String 0101 ANCRFILE 1843.warf String
This means that when the spectra are read into Sherpa, all the supporting files will automatically be read as well; the background (if available) will be defined, as will the source and background response files.
Running mkacisrmf Independently
Users with "good enough" calibration who wish to run mkacisrmf to create new RMF response files should now follow the Using mkacisrmf with the specextract script section of the Creating ACIS RMFs with mkacisrmf thread.
This also applies to users with GRADED mode data on chips S1 or S3 (the back-illuminated chips), as explained in the ACIS GRADED Mode Data section of that thread.
Fitting
If you would like to fit the background-subtracted source spectrum using a common RMF and ARF for source and background, simply read the source spectrum FITS file into Sherpa, subtract the background, and fit it. See the Introduction to Fitting PHA Spectra thread (S-Lang or Python) for details.
To fit source and background spectra simultaneously with distinct RMFs and ARFs, follow the Independent Background Responses thread (S-Lang or Python).
Caveats
Using the ACIS "Blank-Sky" Background Files
Subtracting the Background
If you intend to subtract the background spectrum (i.e. not fit it), then you do not need to create a background RMF and ARF. You may simply use dmextract to create the spectrum. In this case, leave the bkgfile parameter blank so that specextract will only create the source spectrum and responses.
Analysis at the edges of ACIS CCDs
Users should be cautious about analyzing the data for sources near the edges of the ACIS CCDs.
-
For X-rays passing through the mirrors, the very bottom of each CCD is obscured by the frame store. As a result, some of the events in rows with CHIPY <= 8 are not detected. (The set of rows affected varies from CCD to CCD.) Since the CIAO tools do not compensate for this effect, the ARFs and exposure maps for sources in these regions may be inaccurate.
-
For sources within about thirty-two pixels of any edge of a CCD, the source may be dithered off the CCD during part of an observation. The aspect histogram, which is used to create ARFs and exposure maps, is designed to compensate for this effect.
The aspect histogram is not used by specextract. To include this information, it is necessary to run the tool mkwarf independently and supply the aspect information.
-
An ARF calculated at the edge of a chip will not be accurate. The response tools for spectral extraction (specifically the ARF) assume that 100% of the PSF is enclosed - i.e. on the chip - all the time, which may not be the case. The amount of error introduced depends on how close the source is to the edge, the morphology of the source, and the characteristics of the PSF, which depends on the source spectrum.
-
A contaminant has accumulated on the optical-blocking filters of the ACIS detectors, as described in the ACIS QE Degradation why topic. Since there is a gradient in the temperature across the filters (the edges are colder), there is a gradient in the amount of material on the filters. (The contaminant is thicker at the edges.) Within about 100 pixels of the outer edges of the ACIS-I and ACIS-S arrays, the gradient is relatively steep. Therefore, the effective low-energy (' 1 keV) detection efficiency may vary within the dither pattern in this region. The ARF and instrument map tools are designed to read a calibration file which describes this spatial dependence.
Parameters for /home/username/cxcds_param/specextract.par
infile = acis_869_evt2.fits[sky=region(simple.reg)] Source events file(s)
outroot = simple Output directory path + root name for output files
pbkfile = acisf078247287N003_pbk0.fits pbkfile input to mkwarf
(bkgfile = acis_869_evt2.fits[sky=region(bg_simple.reg)]) Background events file(s)
(dafile = CALDB) dafile input to mkwarf
(ptype = PI) PI or PHA
(grouptype = NUM_CTS) Spectrum grouping type (same as grouptype in dmgroup)
(binspec = 15) Spectrum grouping specification (NONE,1:1024:10,etc)
(bkg_grouptype = NONE) Background spectrum grouping type (NONE, BIN, SNR, NUM_BINS, NUM_CTS, or ADAPTIVE)
(bkg_binspec = ) Background spectrum grouping specification (NONE,10,etc)
(energy = 0.3:11.0:0.01) Energy grid
(channel = 1:1024:1) RMF binning attributes
(energy_wmap = 300:2000) Energy Range for WMAPs
(binwmap = det=8) Binning factor for WMAPs
(clobber = no) OK to overwrite existing output file?
(verbose = 0) Debug Level(0-5)
(mode = ql)
|
Parameters for /home/username/cxcds_param/specextract.par
infile = @multi_input.lis Source events file(s)
outroot = @multi_out.lis Output directory path + root name for output files
pbkfile = @multi_pbk.lis pbkfile input to mkwarf
(bkgfile = @multi_bkg.lis) Background events file(s)
(dafile = CALDB) dafile input to mkwarf
(ptype = PI) PI or PHA
(grouptype = BIN) Spectrum grouping type (same as grouptype in dmgroup)
(binspec = 10) Spectrum grouping specification (NONE,1:1024:10,etc)
(bkg_grouptype = NONE) Background spectrum grouping type (NONE, BIN, SNR, NUM_BINS, NUM_CTS, or ADAPTIVE)
(bkg_binspec = ) Background spectrum grouping specification (NONE,10,etc)
(energy = 0.3:11.0:0.01) Energy grid
(channel = 1:1024:1) RMF binning attributes
(energy_wmap = 300:2000) Energy Range for WMAPs
(binwmap = det=8) Binning factor for WMAPs
(clobber = no) OK to overwrite existing output file?
(verbose = 0) Debug Level(0-5)
(mode = ql)
|
History
| 01 Feb 2006 | new for CIAO 3.3 |
| 15 Feb 2006 | created Running mkacisrmf Independently section |
| 31 Mar 2006 | specextract use update added to Overview |
| 05 Apr 2006 | In light of the specextract usage change, the thread has been rewritten to use extended sources in the examples |
| 14 Apr 2006 | added Analysis at the edges of ACIS CCDs caveat |
| 24 May 2006 | added new information to Using the ACIS "Blank-Sky" Background Files caveat |
| 14 Jun 2006 | corrected link in "Calibration Updates"; clarified information on GRADED mode data |
| 18 Dec 2006 | updated for CIAO 3.4: new calibration files in CALDB 3.3.0; Extracting Multiple Spectra section uses a stack of output file roots (new feature in CIAO 3.4); output files in one-output case no longer have "src1" or "bkg1" included in the filename; mkrmf no longer prints messages at verbose=0; CIAO version in warnings |
| 06 Mar 2007 | added ACIS dead area correction section |
| 22 Jan 2008 | updated for CIAO 4.0: ACIS dead area correction parameters added to the specextract.par file: pbkfile and dafile (dead area correction is turned on by default); new ACIS blank-sky background file in CALDB 3.4.0 eliminate the header keyword issue; available links point to the Sherpa Beta website; removed outdated calibration updates |
| 31 Mar 2008 | updated for CALDB 3.4.3: use mkacisrmf for -110 BI chips if TGAIN calibration has been applied |
| 26 Jun 2008 | updated Analysis at the edges of ACIS CCDs caveats (aspect information not taken into account by specextract) |
| 04 Feb 2009 | updated for CIAO 4.1: images are inline; Sherpa link updated to 4.1 website; screen output changed with CALDB 4; input data must have a CTI_APP keyword |
| 17 Feb 2009 | added "for Extended Sources" to the title |
