Skip to the navigation links
Last modified: 22 Mar 2010
Where are the PDFs?

Using specextract to Extract ACIS Spectra and Response Files for Extended Sources

CIAO 4.2 Science Threads



Overview

Last Update: 22 Mar 2010 - added "Special case: -110 C data on a front-illuminated chip" to the Creating RMFs: mkrmf vs mkacisrmf section

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.

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.

Calibration Updates:




Contents



How specextract Works

specextract runs the dmextract, mkwarf, mkrmf or mkacisrmf, 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.

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

As of CIAO 4.2, specextract uses the input event file to query the CALDB for a P2_RESP file, the calibration used by mkacisrmf. If a calibration file exists, specextract run mkacisrmf to create the RMF. This improvement means that specextract will choose mkacisrmf for all the valid observation cases listed above.

If there is no calibration match, mkrmf is used to create the RMF. At higher verbosities, a message of this form will be printed to the screen:

Cannot use mkacisrmf because no P2_RESP files were found
Please reprocess <filename> with acis_process_events if you wish to use mkacisrmf
Using mkrmf...

In this case, it is necessary to reprocess the data before running specextract if you wish to use mkacisrmf.

Special case: -110 C data on a front-illuminated chip

If the input file contains -110 C data and has the CTI-correction applied, specextract will always choose to use the mkacisrmf tool. However, if the source of interest is actually on a front-illuminated chip, the mkacisrmf step fails with an error:

unix% # mkacisrmf (CIAO 4.2): ERROR: No non-zero pixels map to valid
chip coordinates in the supplied wmap='src.pi[WMAP]' file

mkacisrmf infile=CALDB outfile=src.wrmf energy="0.3:11.0:0.01"
channel="1:1024:1" chantype=PI wmap=src.pi"[WMAP]" gain=CALDB
clobber=yes verbose=2 mode=h  failed.

Error: Failed to create RMF for evt2.fits[sky=region(src.reg)]

Removing products related to current input file only.

In this case, the user must run mkrmf independently to create the RMF file.



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.

Choosing a background file

The examples in this thread use a background region that was chosen from a from source-free area of the same chip as the source region. The source or a field of sources may cover the chip, however, making it impossible to select a local background. There are several options in this case:

  • Choose the background from another same-type chip that was on in the observation. If your source is on ACIS-S3 and ACIS-S1 (the other back-illuminated chip) was also turned on, define the background on ACIS-S1.

  • If using another chip from the observation is not an option, use one of the ACIS "Blank-Sky" Background Files (S-Lang or Python) which are distributed in the CALDB.

    If you plan on using one of the ACIS "blank-sky" background files from the CALDB with specextract, read the Using the ACIS "Blank-Sky" Background Files caveats before continuing.

  • Omit the background completely (i.e. leave the bkgfile blank)

Setting the energy range

The ACIS detector is calibrated over the range 0.224004 - 12 keV; choosing an energy range outside these values will result in errors from the tools called by script.

The default energy parameter value, 0.3:11.0:0.01, is suitable for most analyses.



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 acisf00869N003_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 so that they are fully compatible with the analysis tools.

[Thumbnail image: The source region and the background region are each a single ellipse.]

[Version: full-size]

[Print media version: The source region and the background region are each a single ellipse.]

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="acisf00869N003_evt2.fits[sky=region(simple.reg)]"
unix% pset specextract outroot=simple
unix% pset specextract bkgfile="acisf00869N003_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) (acisf00869N003_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      = acisf00869N003_evt2.fits[sky=region(simple.reg)][bin PI]
 VERBOSE: outfile     = simple.pi
 VERBOSE: Creating output file simple.pi
 VERBOSE: Write WMAP using acisf00869N003_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      = acisf00869N003_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 acisf00869N003_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.]

[Version: full-size]

[Print media version: The two event files used for spectral extraction are displayed in ds9 with the source and background regions overlaid.]

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
acisf01842N002_evt2.fits[sky=region(1842_src.reg)]
acisf01843N002_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
acisf01842N002_evt2.fits[sky=region(1842_bg.reg)]
acisf01843N002_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.


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.



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 for details.

To fit source and background spectra simultaneously with distinct RMFs and ARFs, follow the Independent Background Responses thread.



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.

  1. 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.

  2. 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.

  3. 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.

  4. A contaminant has accumulated on the optical-blocking filters of the ACIS detectors, as described in the ACIS QE Contamination 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 = acisf00869N003_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 = acisf00869N003_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
12 Jan 2010 updated for CIAO 4.2: specextract uses a CALDB query to decide which RMF tool should be used; calibration update - the ACIS QE contamination model has been upgraded to vN0005.
05 Mar 2010 added additional information to the Choosing a background file section
09 Mar 2010 The ACIS detector is calibrated over the range 0.224004 - 12 keV; choosing values outside this range will result in errors from specextract.
22 Mar 2010 added "Special case: -110 C data on a front-illuminated chip" to the Creating RMFs: mkrmf vs mkacisrmf section

Return to Threads Page: Top | All | Imag Spec

Where are the PDFs?
Last modified: 22 Mar 2010