There is a script called xmmspec.csh which will then extract a source and background spectrum, make an arf and rmf file, group the spectrum, and associate the response files so the output can be read directly into xspec or sherpa.
For example, I defined source and background regions for my mos1 data, called mos1source70arcs.reg and mos1bg200arcs.reg and then use xmmspec as follows:
xun4> xmmspec.csh mos1_clean_evt.fits mos1source70arcs.reg mos1bg200arcs.reg
none rmfgen mos1spec_ |& tee mos1spec_log.txt
--------------------XMMSPEC.CSH version 1---------------------
Input was /exgal1/bjm/scripts/xmmspec.csh mos1_clean_evt.fits
mos1source70arcs.reg mos1bg200arcs.reg none rmfgen mos1spec_
Attempting to detect previous filtering from table statistics...
events were filtered between pattern(s) 0 - 12
Instrument is EMOS1 - using PI = 0-11999 channels in 15 channels bins
single and double events (pattern <= 12) are in use.
Centre of region is (x,y) = 30464,26400 - If the region is not simple this
may be incorrect.
Extracting source spectrum...
evselect table=mos1_clean_evt.fits:EVENTS withspectrumset=yes
spectrumset=mos1spec_spec.fits energycolumn=PI spectralbinsize=15
withspecranges=true specchannelmin=0 specchannelmax=11999 writedss=yes
expression=(circle(30464,26400,1400,X,Y))
source spectrum written to mos1spec_spec.fits
Extracting background spectrum...
evselect table=mos1_clean_evt.fits:EVENTS withspectrumset=yes
spectrumset=mos1spec_bgspec.fits energycolumn=PI spectralbinsize=15
withspecranges=true specchannelmin=0 specchannelmax=11999 writedss=yes
expression=(circle(23520,26624,4000,X,Y))
background spectrum written to mos1spec_bgspec.fits
Generating RMF...
rmfgen spectrumset=mos1spec_spec.fits rmfset=mos1spec_rmf.fits threshold=1e-5
withenergybins=false pnline=0
RMF written to mos1spec_rmf.fits
Making detector map to weight ARF...
evselect table=mos1_clean_evt.fits:EVENTS destruct=false withfilteredset=true
withimageset=true imageset=mos1spec_detmap.fits xcolumn=DETX ycolumn=DETY
imagebinning=binSize ximagebinsize=120 yimagebinsize=120
expression=(circle(30464,26400,1400,X,Y)) writedss=true updateexposure=true
** evselect: warning (NoWCS), No WCS information available for image column DETX.
** evselect: warning (NoWCS), No WCS information available for image column DETY.
detector map written to mos1spec_detmap.fits
arfgen spectrumset=mos1spec_spec.fits arfset=mos1spec_arf.fits detmaptype=dataset
detmaparray=mos1spec_detmap.fits: extendedsource=yes withrmfset=true
rmfset=mos1spec_rmf.fits setbackscale=yes withbadpixcorr=true
badpixlocation=mos1_clean_evt.fits withfilteredset=true
filteredset=mos1spec_detmap_filter.fits withsourcepos=yes sourcecoords=pos
sourcex=30464 sourcey=26400
** arfgen::attcalc: warning (outOfImageRange), 401 events ( of 110885 ) out
of range of image
ARF written to mos1spec_arf.fits
Computing BACKSCAL for background spectrum...
backscale spectrumset=mos1spec_bgspec.fits withbadpixcorr=yes
badpixlocation=mos1_clean_evt.fits
Associating background spectrum and grouping counts into bins >= 20 using rmf
mos1spec_rmf.fits and arf mos1spec_arf.fits
Output written to mos1spec_spec_grppha.fits
----------------------------------------------------------------------------------
Now I repeat this for mos2 and the pn camera. Note that rmfgen and arfgen may
take a longish time to run (maybe even a few hours). The script gives you the
choice to use one of the pre-generated rmfs that come as part of the
calibration, however I've had problems with these giving me strange flux
estimates later on, so I generally use rmfgen.
xun4> xspec
Xspec 11.1.0 12:15:29 10-Jan-2002
For documentation, notes, and fixes see http://xspec.gsfc.nasa.gov/
Plot device not set, use "cpd" to set it
Type "help" or "?" for further information
XSPEC>data mos1spec_spec_grppha.fits mos2spec_spec_grppha.fits
Net count rate (cts/s) for file 1 8.2745E-02+/- 2.5138E-03( 61.4% total)
using response (RMF) file... mos1spec_rmf.fits
using auxiliary (ARF) file... mos1spec_arf.fits
using background file... mos1spec_bgspec.fits
Net count rate (cts/s) for file 2 9.4467E-02+/- 2.6441E-03( 63.6% total)
using response (RMF) file... mos2spec_rmf.fits
using auxiliary (ARF) file... mos2spec_arf.fits
using background file... mos2spec_bgspec.fits
2 data sets are in use
XSPEC>cpd /xw
XSPEC>setplot energy
XSPEC>ignore 0-0.3
XSPEC>ignore 8.0-**
XSPEC>plot data
XSPEC>model wabs*mekal
Model: wabs[1]( mekal[2] )
Input parameter value, delta, min, bot, top, and max values for ...
Current: 1 0.001 0 0 1E+05 1E+06
wabs:nH>0.0138
Current: 1 0.01 0.001 0.001 100 100
mekal:kT>7
Current: 1 -0.01 1E-06 1E-05 1E+19 1E+20
mekal:nH>0.001
Current: 1 -0.01 0 0 1E+03 1E+03
mekal:Abundanc>0.3
Current: 0 -0.01 0 0 10 10
mekal:Redshift>0.888
Current: 1 -1 0 0 1 1
mekal:Switch>
Current: 1 0.01 0 0 1E+24 1E+24
mekal:norm>
---------------------------------------------------------------------------
---------------------------------------------------------------------------
Model: wabs[1]( mekal[2] )
Model Fit Model Component Parameter Unit Value
par par comp
1 1 1 wabs nH 10^22 1.3800E-02 +/- 0.
2 2 2 mekal kT keV 7.000 +/- 0.
3 3 2 mekal nH cm-3 1.0000E-03 frozen
4 4 2 mekal Abundanc 0.3000 frozen
5 5 2 mekal Redshift 0.8880 frozen
6 6 2 mekal Switch 1.000 frozen
7 7 2 mekal norm 1.000 +/- 0.
---------------------------------------------------------------------------
---------------------------------------------------------------------------
Chi-Squared = 1.3758436E+09 using 211 PHA bins.
Reduced chi-squared = 6614632. for 208 degrees of freedom
Null hypothesis probability = 0.
XSPEC>freeze 1
Number of variable fit parameters = 2
XSPEC>fit 1000
Chi-Squared Lvl Fit param # 1 2 3 4
5 6 7
232.120 -3 1.3800E-02 9.237 1.0000E-03 0.3000
0.8880 1.000 1.1865E-03
227.303 -4 1.3800E-02 10.11 1.0000E-03 0.3000
0.8880 1.000 1.2840E-03
226.436 -5 1.3800E-02 10.37 1.0000E-03 0.3000
0.8880 1.000 1.2146E-03
225.918 -6 1.3800E-02 10.37 1.0000E-03 0.3000
0.8880 1.000 1.2686E-03
225.590 -7 1.3800E-02 10.37 1.0000E-03 0.3000
0.8880 1.000 1.2265E-03
225.399 -8 1.3800E-02 10.37 1.0000E-03 0.3000
0.8880 1.000 1.2592E-03
225.279 -9 1.3800E-02 10.37 1.0000E-03 0.3000
0.8880 1.000 1.2337E-03
225.208 -10 1.3800E-02 10.38 1.0000E-03 0.3000
0.8880 1.000 1.2536E-03
225.164 -11 1.3800E-02 10.37 1.0000E-03 0.3000
0.8880 1.000 1.2381E-03
225.138 -12 1.3800E-02 10.37 1.0000E-03 0.3000
0.8880 1.000 1.2502E-03
225.122 -13 1.3800E-02 10.37 1.0000E-03 0.3000
0.8880 1.000 1.2408E-03
225.112 -14 1.3800E-02 10.37 1.0000E-03 0.3000
0.8880 1.000 1.2481E-03
---------------------------------------------------------------------------
Variances and Principal axes :
2 7
1.40E+00 | -1.00 0.00
2.17E-09 | 0.00 -1.00
---------------------------------------------------------------------------
---------------------------------------------------------------------------
Model: wabs[1]( mekal[2] )
Model Fit Model Component Parameter Unit Value
par par comp
1 1 1 wabs nH 10^22 1.3800E-02 frozen
2 2 2 mekal kT keV 10.37 +/- 1.183
3 3 2 mekal nH cm-3 1.0000E-03 frozen
4 4 2 mekal Abundanc 0.3000 frozen
5 5 2 mekal Redshift 0.8880 frozen
6 6 2 mekal Switch 1.000 frozen
7 7 2 mekal norm 1.2481E-03 +/- 0.4694E-04
---------------------------------------------------------------------------
---------------------------------------------------------------------------
Chi-Squared = 225.1121 using 211 PHA bins.
Reduced chi-squared = 1.077091 for 209 degrees of freedom
Null hypothesis probability = 0.212
XSPEC>plot data
XSPEC>error 2 1.0
Parameter Confidence Range ( 1.000)
2 9.28255 11.5644
XSPEC>new 1 0.0
2 variable fit parameters
Chi-Squared = 228.0797 using 211 PHA bins.
Reduced chi-squared = 1.091290 for 209 degrees of freedom
Null hypothesis probability = 0.174
XSPEC>flux 0.5 2.0
Model flux 1.6547E-04 photons ( 2.6600E-13 ergs)cm**-2 s**-1 ( 0.500- 2.000) DtSet : 1
Model flux 1.6547E-04 photons ( 2.6600E-13 ergs)cm**-2 s**-1 ( 0.500- 2.000) DtSet : 2
XSPEC>flux 0.0 10.0
Lower range 0. reset by matrix bound to 0.205
Model flux 3.9504E-04 photons ( 7.7979E-13 ergs)cm**-2 s**-1 ( 0.205- 10.000) DtSet : 1
Lower range 0. reset by matrix bound to 0.205
Model flux 3.9504E-04 photons ( 7.7979E-13 ergs)cm**-2 s**-1 ( 0.205- 10.000) DtSet : 2