Skip to the navigation links
Last modified: 12 Jan 2010
Where are the PDFs?

Step-by-Step Guide to Creating ACIS Spectra for Pointlike Sources

CIAO 4.2 Science Threads



Overview

Last Update: 12 Jan 2010 - updated for CIAO 4.2: ObsID 459 file versions and corresponding minor changes to screen output; calibration update - the ACIS QE contamination model has been upgraded to vN0005.

Synopsis:

Using a combination of CIAO tools, we extract source and background spectra for a pointlike source. The background spectrum is grouped, if desired. The appropriate Response Matrix Files (RMFs) and Ancillary Response Files (ARFs) are also created for both source and background.

Purpose:

To generate source and background PI (PHA) spectra of a pointlike ACIS source and build the proper RMFs and ARFs.

Read this thread if:

you are working with any ACIS observation, whether imaging or grating data.

Calibration Updates:

Related Links:




Contents



Get Started

Sample ObsID used: 459 (HETG/ACIS-S, 3C 273)

File types needed: evt2; asol1; pbk0

Please ensure that you have set up ardlib to use the bad pixel file for your observation before following this thread.

Using Consistent Calibration: 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. This thread gives the syntax for both tools in the Calculate the RMFs section; it is up to the user to chose the appropriate method for the analysis.

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.



Downloading acis_fef_lookup

This thread uses the acis_fef_lookup script, which is part of the CIAO Scripts distribution. The CIAO scripts package should be the following version or newer:

unix% cat $ASCDS_CONTRIB/VERSION.CIAO_scripts
17 Apr 2009

Please check that you have at least this version of the scripts package installed before continuing. If you do not have the scripts installed or need to update to a newer version, refer to the Scripts page.



Extract Spectrum of Object

1. Determine Position of Source (ds9)

We need to define two regions, one for the source and another for the background. To do this, first display the data:

unix% ds9 acisf00459N004_evt2.fits &

In this example, we define the jet as the source with a rectangle (see FAQ on how to rotate shapes in ds9) and four 10-pixel radius circles for the background (from source-free parts of the data around the source). All the regions are shown in Figure 1. The background region can also be selected from a different chip or different event file, if desired.

To save the regions:

  1. Region → Save Regions... → Save As "3c273.reg" (source) and "3c273_bg.reg" (background). To select multiple regions for saving, hold down the <SHIFT> key and click on each one.
  2. After choosing "OK" in the region filename dialog, a format dialog is opened. Set the format to "CIAO" and the coordinate system to "Physical".
[Thumbnail image: The source region around the jet is a rotated rectangle; the background region is comprised of four circles.]

[Version: full-size]

[Print media version: The source region around the jet is a rotated rectangle; the background region is comprised of four circles.]

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.

The resulting region files will look something like this:

unix% more 3c273.reg
# Region file format: CIAO version 1.0
rotbox(4148.125,4043.625,7.58978,22.338761,44.516094)

unix% more 3c273_bg.reg
# Region file format: CIAO version 1.0
circle(4119,4014.75,10)
circle(4077,4025.75,10)
circle(4186.5,4023.25,10)
circle(4196.25,4064.5,10)

2. Extract Source and Background Spectra (dmextract)

In this example, we extract the spectra in pulse invariant (PI) space. This creates a histogram of number of counts vs. PI channel:

unix% punlearn dmextract
unix% pset dmextract infile="acisf00459N004_evt2.fits[sky=region(3c273.reg)][bin pi]"
unix% pset dmextract outfile=3c273.pi
unix% dmextract
Input event file  (acisf00459N004_evt2.fits[sky=region(3c273.reg)][bin pi]): 
Enter output file name (3c273.pi):

And for the background spectrum:

unix% pset dmextract infile="acisf00459N004_evt2.fits[sky=region(3c273_bg.reg)][bin pi]"
unix% pset dmextract outfile=3c273_bg.pi
unix% dmextract
Input event file  (acisf00459N004_evt2.fits[sky=region(3c273_bg.reg)][bin pi]): 
Enter output file name (3c273_bg.pi): 

You can check the parameter file that was used with plist dmextract.


3. Locate Centroids (dmstat)

Since the calibration varies across the chips, we need to locate the centroid (in chip coordinates) of the source and background regions. This information is needed to create the ARFs, as well as to select which FEF (FITS Embedded Function) to use in calculating the RMFs with mkrmf. For the source:

unix% dmstat "acisf00459N004_evt2.fits[sky=region(3c273.reg)][cols chipx,chipy,ccd_id,x,y]"
chip(chipx, chipy)[pixel]
    min:	( 260 350 )	      @:	( 153 443 )
    max:	( 311 392 )	      @:	( 164 25 )
   mean:	( 282.43352601 372.19845857 )
  sigma:	( 12.248821787 11.744761368 )
    sum:	( 146583 193171 )
   good:	( 519 519 )
   null:	( 0 0 )

ccd_id
    min:	7 	      @:	1 
    max:	7 	      @:	1 
   mean:	7 
  sigma:	0 
    sum:	3633 
   good:	519 
   null:	0 

sky(x, y)[pixel]
    min:	( 4138.565918 4035.0893555 )	      @:	( 365 164 )
    max:	( 4155.7944336 4052.7905273 )	      @:	( 167 314 )
   mean:	( 4144.2868365 4046.6510732 )
  sigma:	( 3.513813344 3.7447860531 )
    sum:	( 2150884.8682 2100211.907 )
   good:	( 519 519 )
   null:	( 0 0 )

The centroid of the source distribution is at chipx = 282.43 and chipy = 372.20. Note also that the source position is x = 4144.29 and y = 4046.65 and is on CCD 7 (ACIS-S3).

And for the background:

unix% dmstat "acisf00459N004_evt2.fits[sky=region(3c273_bg.reg)][cols chipx,chipy,ccd_id,x,y]"
chip(chipx, chipy)[pixel]
    min:	( 252 296 )	      @:	( 136 57 )
    max:	( 343 465 )	      @:	( 87 54 )
   mean:	( 293.6076555 382.18660287 )
  sigma:	( 20.953334771 50.746566221 )
    sum:	( 61364 79877 )
   good:	( 209 209 )
   null:	( 0 0 )

ccd_id
    min:	7 	      @:	1 
    max:	7 	      @:	1 
   mean:	7 
  sigma:	0 
    sum:	1463 
   good:	209 
   null:	0 

sky(x, y)[pixel]
    min:	( 4068.8461914 4005.0986328 )	      @:	( 9 51 )
    max:	( 4205.9257812 4074.0290527 )	      @:	( 173 86 )
   mean:	( 4140.4038366 4031.5951926 )
  sigma:	( 48.516897207 20.060247953 )
    sum:	( 865344.40186 842603.39526 )
   good:	( 209 209 )
   null:	( 0 0 )

The centroid of the background distribution is at chipx = 293.61 and chipy = 382.19. Again, note that the mean position is at x = 4140.40 and y = 4031.60 and is also on ACIS-S3. You can check the parameter file that was used with plist dmstat.



Calculate the RMFs

The observation used in this thread (ObsID 459) was taken at the -110 C focal plane temperature and the source is on ACIS-7, a back-illuminated chip. Therefore, it is possible to use mkacisrmf to create the RMF file, assuming the dataset was reprocessed with CALDB 3.4.3 or higher.

The syntax for both mkacisrmf and mkrmf are given in this section. Users should choose the appropriate tool for the data and calibration.

A. Using mkacisrmf (mkacisrmf)

The Creating ACIS RMFs with mkacisrmf thread has more details on using the mkacisrmf tool. This example is for -110 C data on a BI chip; users with -120 C data should refer to the mkacisrmf thread for the correct syntax for that case.

For the source:

unix% dmkeypar acisf00459N004_evt2.fits gainfile echo+
acisD1999-09-16gainN0006.fits

unix% punlearn mkacisrmf
unix% pset mkacisrmf infile=$CALDB/data/chandra/acis/p2_resp/acisD2000-01-29p2_respN0005.fits
unix% pset mkacisrmf outfile=3c273_mkacisrmf.rmf
unix% pset mkacisrmf energy=0.1:11.0:0.01
unix% pset mkacisrmf channel=1:1024:1
unix% pset mkacisrmf chantype=PI
unix% pset mkacisrmf wmap=none
unix% pset mkacisrmf ccd_id=7 chipx=282.43 chipy=372.20
unix% pset mkacisrmf gain=$CALDB/data/chandra/acis/det_gain/acisD1999-09-16gainN0006.fits

unix% mkacisrmf
scatter/rsp matrix file (/soft/ciao/CALDB/data/chandra/acis/p2_resp/acisD2000-01-29p2_respN0005.fits):
RMF output file (3c273_mkacisrmf.rmf):
WMAP file (none):
energy grid in keV (lo:hi:bin) (0.1:11.0:0.01):
channel grids in pixel (min:max:bin) (1:1024:1):
channel type (PI|PHA) (PI):
filter CCD-ID (0:9) (7):
filter chipx in pixel (282):
ficlter chipy in pixel (372):
gain file (/soft/ciao/CALDB/data/chandra/acis/det_gain/acisD1999-09-16gainN0006.fits):

INFO: Effective user energy (keV) grids will be re-arranged in
     0.25000 - 11.00000


Single region, #2316 , processed.

For the background, repeat the command with the background chipx and chipy values:

unix% pset mkacisrmf outfile=3c273_bg_mkacisrmf.rmf
unix% pset mkacisrmf ccd_id=7 chipx=293.61 chipy=382.19

unix% mkacisrmf
scatter/rsp matrix file (/soft/ciao/CALDB/data/chandra/acis/p2_resp/acisD2000-01-29p2_respN0005.fits):
RMF output file (3c273_bg_mkacisrmf.rmf):
WMAP file (none):
energy grid in keV (lo:hi:bin) (0.1:11.0:0.01):
channel grids in pixel (min:max:bin) (1:1024:1):
channel type (PI|PHA) (PI):
filter CCD-ID (0:9) (7):
filter chipx in pixel (293):
ficlter chipy in pixel (382):
gain file (/soft/ciao/CALDB/data/chandra/acis/det_gain/acisD1999-09-16gainN0006.fits):

INFO: Effective user energy (keV) grids will be re-arranged in
     0.25000 - 11.00000


Single region, #2348 , processed.

You can check the parameter file that was used with plist mkacisrmf.

If you use mkacisrmf to create the RMFs, you can now continue to the Calculate the ARFs step.


B. Using mkrmf (acis_fef_lookup, mkrmf)

First acis_fef_lookup is needed to determine the correct FEFs. For the source:

unix% punlearn acis_fef_lookup
unix% acis_fef_lookup acisf00459N004_evt2.fits 7 280.29 373.73
/soft/ciao/CALDB/data/chandra/acis/fef_pha/acisD1999-09-16fef_phaN0002.fits[FUNCTION][ccd_id=7,chipx=257:288,chipy=353:384]

and for the background:

unix% acis_fef_lookup acisf00459N004_evt2.fits 7 293.61 382.19
/soft/ciao/CALDB/data/chandra/acis/fef_pha/acisD1999-09-16fef_phaN0002.fits[FUNCTION][ccd_id=7,chipx=289:320,chipy=353:384]

You can check the parameter file that was used with plist acis_fef_lookup.

Now that we have the FEFs, we can compute RMFs with mkrmf. It is important that the axes are defined correctly. The energy range (keV) for axis1 should cover the detector response range, which is ~0.2-12 keV for ACIS-S. The default for extraction in PI space is axis2=1:1024:1; in PHA space it would be 1:4096:2.

For the source:

unix% punlearn mkrmf
unix% pset mkrmf infile="/soft/ciao/CALDB/data/chandra/acis/fef_pha/acisD1999-09-16fef_phaN0002.fits[FUNCTION][ccd_id=7,chipx=257:288,chipy=353:384]"
unix% pset mkrmf outfile=3c273.rmf
unix% pset mkrmf axis1="energy=0.1:11.0:0.01"
unix% pset mkrmf axis2="pi=1:1024:1"
unix% mkrmf
name of FEF input file (/soft/ciao/CALDB/data/chandra/acis/fef_pha/acisD1999-09-16fef_phaN0002.fits
[FUNCTION][ccd_id=7,chipx=257:288,chipy=353:384]): 
name of RMF output file (3c273.rmf): 
axis-1(name=lo:hi:btype) (energy=0.1:11.0:0.01): 
axis-2(name=lo:hi:btype) (pi=1:1024:1): 

and for the background:

unix% pset mkrmf infile="/soft/ciao/CALDB/data/chandra/acis/fef_pha/acisD1999-09-16fef_phaN0002.fits[FUNCTION][ccd_id=7,chipx=289:320,chipy=353:384]"
unix% pset mkrmf outfile=3c273_bg.rmf
unix% pset mkrmf axis1="energy=0.1:11.0:0.01"
unix% pset mkrmf axis2="pi=1:1024:1"
unix% mkrmf
name of FEF input file (/soft/ciao/CALDB/data/chandra/acis/fef_pha/acisD1999-09-16fef_phaN0002.fits
[FUNCTION][ccd_id=7,chipx=289:320,chipy=353:384]): 
name of RMF output file (3c273_bg.rmf): 
axis-1(name=lo:hi:btype) (energy=0.1:11.0:0.01): 
axis-2(name=lo:hi:btype) (pi=1:1024:1): 

You can check the parameter file that was used with plist mkrmf.



Calculate the ARFs

1. Compute the Aspect Histogram (asphist)

We now need to create the aspect histogram, which is a binned representation of aspect motion during the observation:

unix% punlearn asphist
unix% pset asphist infile=@pcad_asol1.lis
unix% pset asphist outfile=3c273.asphist
unix% pset asphist evtfile="acisf00459N004_evt2.fits[ccd_id=7]"
unix% asphist
Aspect Solution List Files (@pcad_asol1.lis): 
Aspect Histogram Output File (3c273.asphist): 
Event List Files (acisf00459N004_evt2.fits[ccd_id=7]): 

In many cases, there will be more than one aspect solution file (pcad_asol1.fits) for an observation. All the files must be input to the infile parameter, either as a list or as a stack. Here we use:

unix% cat pcad_asol1.lis 
pcadf063874624N003_asol1.fits

You can check the parameter file that was used with plist asphist.


2. Compute the ARFs (mkarf)

The grating parameter in mkarf is set to reflect whether or not grating data is being used. For non-grating observations, this parameter is left at the default (NONE). You can double-check the grating information in the file header:

unix% dmkeypar acisf00459N004_evt2.fits GRATING echo+
HETG

In this case, since we are using an ACIS/HETG observation, mkarf will extract the 0th order spectrum and ARF. The sourcepixelx and sourcepixely were found in the Locate Centroids step. The energy grid (engrid) must be the same as that used for the axis in mkrmf, so the RMF file is used to define it.

To obtain an accurate ARF at the very edge of a CCD, subarray or window, it is necessary to include the mask file (msk1.fits).

unix% punlearn mkarf
unix% pset mkarf grating=HETG
unix% pset mkarf detsubsys=ACIS-S3
unix% pset mkarf outfile=3c273.arf
unix% pset mkarf asphistfile="3c273.asphist[ASPHIST]"
unix% pset mkarf obsfile="acisf00459N004_evt2.fits[EVENTS]"
unix% pset mkarf maskfile=acisf00459_000N003_msk1.fits
unix% pset mkarf pbkfile=acisf063875928N003_pbk0.fits
unix% pset mkarf dafile=CALDB
unix% pset mkarf engrid="grid(3c273_mkacisrmf.rmf[cols ENERG_LO,ENERG_HI])"
unix% pset mkarf sourcepixelx=4144.29
unix% pset mkarf sourcepixely=4046.65

Run mkarf for the source:

unix% mkarf
Aspect Histogram File (3c273.asphist[ASPHIST]): 
Output File Name (3c273.arf): 
Source X Pixel (4144.29): 
Source Y Pixel (4046.65): 
Energy grid spec (grid(3c273_mkacisrmf.rmf[cols ENERG_LO,ENERG_HI])): 
Name of fits file with obs info (evt file -- include extension) (acisf00459N004_evt2.fits[EVENTS]): 
Verbosity (0:5) (0): 
Detector Name (ACIS-S3): 
Grating for zeroth order ARF (NONE|LETG|HETG) (HETG): 
NONE, or name of ACIS window mask file (acisf00459_000N003_msk1.fits): 
NONE, or the name of the parameter block file (acisf063875928N003_pbk0.fits): 

and for the background:

unix% pset mkarf outfile=3c273_bg.arf
unix% pset mkarf engrid="grid(3c273_bg_mkacisrmf.rmf[cols ENERG_LO,ENERG_HI])"
unix% pset mkarf sourcepixelx=4140.40
unix% pset mkarf sourcepixely=4031.60
unix% mkarf 
Aspect Histogram File (3c273.asphist[ASPHIST]): 
Output File Name (3c273_bg.arf): 
Source X Pixel (4140.40): 
Source Y Pixel (4031.60): 
Energy grid spec (grid(3c273_bg_mkacisrmf.rmf[cols ENERG_LO,ENERG_HI])): 
Name of fits file with obs info (evt file -- include extension) (acisf00459N004_evt2.fits[EVENTS]): 
Verbosity (0:5) (0): 
Detector Name (ACIS-S3): 
Grating for zeroth order ARF (NONE|LETG|HETG) (HETG): 
NONE, or name of ACIS window mask file (acisf00459_000N003_msk1.fits): 
NONE, or the name of the parameter block file (acisf063875928N003_pbk0.fits): 

You can check the parameter file that was used with plist mkarf.



Update Spectrum Files

1. Group the Source Spectrum (dmgroup)

The source spectrum is grouped to have a minimum number of 15 counts per new channel:

unix% punlearn dmgroup
unix% pset dmgroup infile=3c273.pi
unix% pset dmgroup outfile=3c273_grp.pi
unix% pset dmgroup grouptype=NUM_CTS 
unix% pset dmgroup grouptypeval=15
unix% pset dmgroup xcolumn=channel
unix% pset dmgroup ycolumn=counts
unix% dmgroup
Input dataset name (3c273.pi): 
Output dataset name (3c273_grp.pi): 
Grouping type (NONE|BIN|SNR|NUM_BINS|NUM_CTS|ADAPTIVE|ADAPTIVE_SNR|BIN_WIDTH|MIN_SLOPE|MAX_SLOPE|BIN_FILE) (NUM_CTS): 
Grouping type value (15): 
Binning specification (): 
Name of x-axis (channel): 
Name of y-axis (counts): 

You can check the parameter file that was used with plist dmgroup.


2. Group the Background Spectrum (dmgroup)

The background spectrum is binned by a factor of 20:

unix% punlearn dmgroup
unix% pset dmgroup infile=3c273_bg.pi
unix% pset dmgroup outfile=3c273_bg_grp.pi
unix% pset dmgroup binspec=1:1024:20
unix% pset dmgroup grouptype=BIN
unix% pset dmgroup xcolumn=channel
unix% pset dmgroup ycolumn=counts
unix% dmgroup
Input dataset name (3c273_bg.pi): 
Output dataset name (3c273_bg_grp.pi): 
Grouping type (NONE|BIN|SNR|NUM_BINS|NUM_CTS|ADAPTIVE|ADAPTIVE_SNR|BIN_WIDTH|MIN_SLOPE|MAX_SLOPE|BIN_FILE) (BIN): 
Grouping type value (0): 
Binning specification (1:1024:20): 
Name of x-axis (channel): 
Name of y-axis (counts): 

You can check the parameter file that was used with plist dmgroup.


3. Update File Headers (dmhedit)

Finally, update the appropriate header keywords in the both the ungrouped and grouped source PHA files.

Note that the ungrouped background file name is used as the BACKFILE header keyword value. The source grouping is applied to the background grouping when fitting in Sherpa. For fitting only background data, or simultaneous fitting of source and background data, Sherpa can group background dynamically with the group functions; see the Fitting section of this thread for more information.

unix% punlearn dmhedit
unix% dmhedit infile=3c273.pi filelist="" operation=add key=BACKFILE value=3c273_bg.pi
unix% dmhedit infile=3c273.pi filelist="" operation=add key=RESPFILE value=3c273_mkacisrmf.rmf
unix% dmhedit infile=3c273.pi filelist="" operation=add key=ANCRFILE value=3c273.arf

unix% dmhedit infile=3c273_grp.pi filelist="" operation=add key=BACKFILE value=3c273_bg.pi
unix% dmhedit infile=3c273_grp.pi filelist="" operation=add key=RESPFILE value=3c273_mkacisrmf.rmf
unix% dmhedit infile=3c273_grp.pi filelist="" operation=add key=ANCRFILE value=3c273.arf

in the ungrouped background PHA file:

unix% dmhedit infile=3c273_bg.pi filelist="" operation=add key=RESPFILE value=3c273_bg_mkacisrmf.rmf
unix% dmhedit infile=3c273_bg.pi filelist="" operation=add key=ANCRFILE value=3c273_bg.arf

and in the linearly-grouped background PHA file:

unix% dmhedit infile=3c273_bg_grp.pi filelist="" operation=add key=RESPFILE value=3c273_bg_mkacisrmf.rmf
unix% dmhedit infile=3c273_bg_grp.pi filelist="" operation=add key=ANCRFILE value=3c273_bg.arf


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.



Analysis Caveats

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.

  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/dmextract.par


#--------------------------------------------------------------------
#
# DMEXTRACT -- extract columns or counts from an event list
#
#--------------------------------------------------------------------
        infile = acisf00459N004_evt2.fits[sky=region(3c273_bg.reg)][bin pi] Input event file 
       outfile = 3c273_bg.pi      Enter output file name
          (bkg = )                Background region file or fixed background (counts/pixel/s) subtraction
        (error = gaussian)        Method for error determination(poisson|gaussian|<variance file>)
     (bkgerror = gaussian)        Method for background error determination(poisson|gaussian|<variance file>)
      (bkgnorm = 1.0)             Background normalization
          (exp = )                Exposure map image file
       (bkgexp = )                Background exposure map image file
      (sys_err = 0)               Fixed systematic error value for SYS_ERR keyword
          (opt = pha1)            Output file type: pha1 
     (defaults = ${ASCDS_CALIB}/cxo.mdb -> /soft/ciao/datacxo.mdb) Instrument defaults file
         (wmap = )                WMAP filter/binning (e.g. det=8 or default)
      (clobber = no)              OK to overwrite existing output file(s)?
      (verbose = 0)               Verbosity level
         (mode = ql)              
    


Parameters for /home/username/cxcds_param/dmstat.par


        infile = acisf00459N004_evt2.fits[sky=region(3c273.reg)][cols chipx,chipy,ccd_id,x,y] Input file specification
   out_columns = chipx,chipy,ccd_id,x,y Output Column Label
       out_min = 252,296,7,4068.8461914,4005.0986328 Output Minimum Value
   out_min_loc = 136,57,1,9,51    Output Minimum Location Value
       out_max = 343,465,7,4205.9257812,4074.0290527 Output Maximum Value
   out_max_loc = 87,54,1,173,86   Output Maxiumum Location Value
      out_mean = 293.6076555,382.18660287,7,4140.4038366,4031.5951926 Output Mean Value
    out_median =                  Output Median Value
     out_sigma = 20.953334771,50.746566221,0,48.516897207,20.060247953 Output Sigma Value
       out_sum = 61364,79877,1463,865344.40186,842603.39526 Output Sum of Values
      out_good = 209,209,209,209,209 Output Number Good Values
      out_null = 0,0,0,0,0        Output Number Null Values
    out_cnvrgd =                  Converged?
 out_cntrd_log =                  Output Centroid Log Value
out_cntrd_phys =                  Output Centriod Phys Value
out_sigma_cntrd =                  Output Sigma Centriod Value
     (centroid = yes)             Calculate centroid if image?
       (median = no)              Calculate median value?
        (sigma = yes)             Calculate the population standard deviation?
         (clip = no)              Calculate stats using sigma clipping?
       (nsigma = 3)               Number of sigma to clip
      (maxiter = 20)              Maximum number of iterations
      (verbose = 1)               Verbosity level
         (mode = ql)
    


Parameters for /home/username/cxcds_param/mkacisrmf.par


        infile = /soft/ciao/CALDB/data/chandra/acis/p2_resp/acisD2000-01-29p2_respN0005.fits scatter/rsp matrix file
       outfile = 3c273_bg_mkacisrmf.rmf RMF output file
          wmap = none             WMAP file
        energy = 0.1:11.0:0.01    energy grid in keV (lo:hi:bin)
       channel = 1:1024:1         channel grids in pixel (min:max:bin)
      chantype = PI               channel type
        ccd_id = 7                filter CCD-ID
         chipx = 293              filter chipx in pixel
         chipy = 382              ficlter chipy in pixel
          gain = /soft/ciao/CALDB/data/chandra/acis/det_gain/acisD1999-09-16gainN0006.fits gain file
     (asolfile = )                aspect solution file or a stack of asol files
      (obsfile = )wmap -> none)   obs file
      (logfile = )                log file
      (contlvl = 100)             # contour level
      (geompar = geom)            pixlib geometry parameter file
       (thresh = 1e-06)           low threshold of energy cut-off probability
      (clobber = no)              overwrite existing output file (yes|no)?
      (verbose = 0)               verbosity level (0 = no display)
         (mode = ql)
    


Parameters for /home/username/cxcds_param/acis_fef_lookup.par


        infile = acisf00459N004_evt2.fits   Source file (event or spectrum)
        chipid = 7                ACIS chip number
         chipx = 293              ACIS chip x coordinate
         chipy = 382              ACIS chip y coordinate
       outfile = /soft/ciao/CALDB/data/chandra/acis/fef_pha/
acisD1999-09-16fef_phaN0002.fits[FUNCTION][ccd_id=7,chipx=289:320,chipy=353:384] FEF file to use
      (verbose = 0)               Verbose level
         (mode = ql)              
    


Parameters for /home/username/cxcds_param/mkrmf.par


        infile = /soft/ciao/CALDB/data/chandra/acis/fef_pha/
acisD1999-09-16fef_phaN0002.fits[FUNCTION][ccd_id=7,chipx=289:320,chipy=353:384] name of FEF input file
       outfile = 3c273_bg.rmf     name of RMF output file
         axis1 = energy=0.1:11.0:0.01 axis-1(name=lo:hi:btype)
         axis2 = pi=1:1024:1      axis-2(name=lo:hi:btype)
      (logfile = STDOUT)          name of log file
      (weights = )                name of weight file
       (thresh = 1e-5)            low threshold of energy cut-off probability
       (outfmt = legacy)          RMF output format (legacy|cxc)
      (clobber = no)              overwrite existing output file (yes|no)?
      (verbose = 0)               verbosity level (0 = no display)
        (axis3 = none)            axis-3(name=lo:hi:btype)
        (axis4 = none)            axis-4(name=lo:hi:btype)
        (axis5 = none)            axis-5(name=lo:hi:btype)
         (mode = ql)              
    


Parameters for /home/username/cxcds_param/asphist.par


#--------------------------------------------------------------------------
#
#       Parameter file for the ASPECT HISTOGRAM Tool
#
#--------------------------------------------------------------------------
        infile = @pcad_asol1.lis  Aspect Solution List Files
       outfile = 3c273.asphist    Aspect Histogram Output File
       evtfile = acisf00459N004_evt2.fits[ccd_id=7] Event List Files
       dtffile =                  Live Time Correction List Files for HRC
      (geompar = geom)            Parameter file for Pixlib Geometry files
       (res_xy = 0.5)             Aspect Resolution x and y in arcsec
     (res_roll = 600.)            Aspect Resolution roll in arcsec
      (max_bin = 10000.)          Maximal number of bins
      (clobber = no)              Clobber output
      (verbose = 0)               Verbose
         (mode = ql)              
    


Parameters for /home/username/cxcds_param/mkarf.par


   asphistfile = 3c273.asphist[ASPHIST] Aspect Histogram File
       outfile = 3c273_bg.arf     Output File Name
  sourcepixelx = 4140.4           Source X Pixel
  sourcepixely = 4031.6           Source Y Pixel
        engrid = grid(3c273_bg_mkacisrmf.rmf[cols ENERG_LO,ENERG_HI]) Energy grid spec
       obsfile = acisf00459N004_evt2.fits[EVENTS] Name of fits file with obs info (evt file -- include extension)
#
       pbkfile = acisf063875928N003_pbk0.fits NONE, or the name of the parameter block file
     detsubsys = ACIS-S3          Detector Name
       grating = HETG             Grating for zeroth order ARF
      maskfile = acisf00459_000N003_msk1.fits NONE, or name of ACIS window mask file
       verbose = 0                Verbosity
#
       (dafile = CALDB            NONE, CALDB, or name of ACIS dead-area calibration file
#
       (mirror = HRMA)            Mirror Name
#
(ardlibparfile = ardlib.par)      name of ardlib parameter file
      (geompar = geom)            Parameter file for Pixlib Geometry files
      (clobber = no)              Overwrite existing files?
#
         (mode = ql)              Enter mode for parameter file.
    


Parameters for /home/username/cxcds_param/dmgroup.par


        infile = 3c273.pi         Input dataset name
       outfile = 3c273_grp.pi     Output dataset name
     grouptype = NUM_CTS          Grouping type
  grouptypeval = 15               Grouping type value
       binspec =                  Binning specification
       xcolumn = channel          Name of x-axis
       ycolumn = counts           Name of y-axis
      (tabspec = )                Tab specification
    (tabcolumn = )                Name of tab column
     (stopspec = )                Stop specification
   (stopcolumn = )                Name of stop column
    (errcolumn = )                Name of error column
      (clobber = no)              Clobber existing output file?
      (verbose = 0)               Verbosity level
    (maxlength = 0)               Maximum size of groups (in channels)
         (mode = ql)              
    


Parameters for /home/username/cxcds_param/dmgroup.par


        infile = 3c273_bg.pi      Input dataset name
       outfile = 3c273_bg_grp.pi  Output dataset name
     grouptype = BIN              Grouping type
  grouptypeval = 0                Grouping type value
       binspec = 1:1024:20        Binning specification
       xcolumn = channel          Name of x-axis
       ycolumn = counts           Name of y-axis
      (tabspec = )                Tab specification
    (tabcolumn = )                Name of tab column
     (stopspec = )                Stop specification
   (stopcolumn = )                Name of stop column
    (errcolumn = )                Name of error column
      (clobber = no)              Clobber existing output file?
      (verbose = 0)               Verbosity level
    (maxlength = 0)               Maximum size of groups (in channels)
         (mode = ql)              
    

History

14 Dec 2004 updated for CIAO 3.2: created Using Consistent Calibration and Downloading acis_fef_lookup sections
23 Jun 2005 CIAO 3.2.2 patch: new calibration for mkacisrmf is available (see the Using Consistent Calibration: mkrmf vs mkacisrmf section); change to asphist parameter file
15 Dec 2005 updated for CIAO 3.3: Calculate the RMFs section has been updated to show syntax for both mkrmf and mkacisrmf; default value of dmextract error and bkgerror parameters is "gaussian"; updated syntax for asphist (GTI filter is associated with the event file rather than the aspect solution); parameter file changes (dmextract, dmstat)
01 Feb 2006 added link to specextract thread
05 Apr 2006 changed specextract thread link to psextract thread link
14 Jun 2006 corrected link in "Calibration Updates"; clarified information on GRADED mode data
01 Dec 2006 updated for CIAO 3.4: acis_fef_lookup version 1.19 (changes for CTI lookup); parameter file updates for mkarf (obsfile parameter is set to event file instead of aspect histogram file)
02 Feb 2007 updated for CALDB 3.3.0.1 patch
26 Feb 2007 acis_fef_lookup v1.20: Script issues a warning to use mkacisrmf instead of mkrmf when running with CTI-corrected data on certain chips.
06 Mar 2007 added ACIS dead area correction section and example of setting the pbkfile and dafile parameters
11 Apr 2007 fixed typo in mkarf parameter file listing: as of CIAO 3.4, obsfile parameter takes the event file as input instead of redirecting to the asphistfile value.
23 Jan 2008 updated for CIAO 4.0: apply the ACIS dead area correction in the mkarf step (application of the dead area correction is turned on by default); acis_fef_lookup v1.21 (updated to to run under S-Lang v2; functionality is unchanged); when available, links point to 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
24 Oct 2008 added asolfile parameter to mkacisrmf commands
09 Feb 2009 updated for CIAO 4.1: image converted to inline; Sherpa link points to 4.1 website; acis_fef_lookup vCIAO 4.1 - 1.0 (rewritten to be compatible with CALDB 4.1); input data must have a CTI_APP keyword; corrected mkacisrmf commands to use point source syntax
19 Feb 2009 moved Sherpa information from the summary into the Fitting section syntax
06 May 2009 check the version of the CIAO scripts package instead of the individual script
21 May 2009 added explanation of why ungrouped background filename is used in the BACKFILE header keyword of the grouped source spectrum
12 Jan 2010 updated for CIAO 4.2: ObsID 459 file versions and corresponding minor changes to screen output; calibration update - the ACIS QE contamination model has been upgraded to vN0005.

Return to Threads Page: Top | All | Imag Spec

Where are the PDFs?
Last modified: 12 Jan 2010