XMMEPICSOC

Richard SaxtonBackground, Operations & Calibration (BOC) meeting

Madrid, 23/03/10-24/03/10

Recent changes in Epic-related

SAS spectral tasks

Richard Saxton

XMMEPICSOC

Richard SaxtonBackground, Operations & Calibration (BOC) meeting

Madrid, 23/03/10-24/03/10

SPECGROUP

Define the useful range of spectral channels Group channels according to statistical criteria Set keywords for spectral fitting programs Currently works on EPIC and RGS spectra (others ?) Enhanced version of GRPPHA

A new SAS task to:

A new SAS task designed to:

XMMEPICSOC

Richard SaxtonBackground, Operations & Calibration (BOC) meeting

Madrid, 23/03/10-24/03/10

Setting bad channelsBad ranges pre-defined in XMM_SPECQUAL CCF.

Screenshot

Of

CCF blocks

specgroup spectrumset=myspec.ds setbad=CCF

Or can be set explicitely:

specgroup spectrumset=myspec.ds setbad=“0.0-0.4 10.0-25.0” units=KEV rmfset=epn.rmf

specgroup spectrumset=myspec.ds setbad=“0-10 1100-1200”

MOS, PN

RGS

XMMEPICSOC

Richard SaxtonBackground, Operations & Calibration (BOC) meeting

Madrid, 23/03/10-24/03/10

Screenshot

Of

CCF blocks

MOS, PN

RGS

XMMEPICSOC

Richard SaxtonBackground, Operations & Calibration (BOC) meeting

Madrid, 23/03/10-24/03/10

Grouping options Manually set the ranges

specgroup spectrumset=myspec.ds ranges=“0-10 11-20 1100-1200” Regular binning

specgroup spectrumset=myspec.ds regbinstart=1 regbinwid=10

Group by counts

specgroup spectrumset=myspec.ds mincounts=25

Group by signal to noise

specgroup spectrumset=myspec.ds minsn=5

Group by ratio to background

specgroup spectrumset=myspec.ds backgndset=mybgd.ds minratio=3 Combination

specgroup spectrumset=myspc.ds minsn=5 ranges=“0:10 1100:1200”

XMMEPICSOC

Richard SaxtonBackground, Operations & Calibration (BOC) meeting

Madrid, 23/03/10-24/03/10

End bin options

Set ungrouped pixels bad:

specgroup spectrumset=myspec.ds minsn=5 lastbin=setbad

Add them to the adjacent group

specgroup spectrumset=myspec.ds mincounts=25 lastbin=addtogroup

Set them as an independent group

specgroup spectrumset=myspec.ds minsn=5 lastbin=owngroup

Group from low or high energies

specgroup spectrumset=myspec.ds minsn=4 hightolow=yes

XMMEPICSOC

Richard SaxtonBackground, Operations & Calibration (BOC) meeting

Madrid, 23/03/10-24/03/10

Energy resolution Use fraction of resolution defined in CCF

specgroup spectrumset=myspec.ds minsn=5 oversample=3

rmfset=mymos.rmf

This ensures that any one group is

at least as wide as the energy resolution

at the central energy of the group divided

by the oversampling factor.

Energy resolution is stored in the

XMM_SPECQUAL CCF:MOS PN

XMMEPICSOC

Richard SaxtonBackground, Operations & Calibration (BOC) meeting

Madrid, 23/03/10-24/03/10

MOS PN

XMMEPICSOC

Richard SaxtonBackground, Operations & Calibration (BOC) meeting

Madrid, 23/03/10-24/03/10

Keyword setting

By default the program sets the BACKFILE, ANCRFILE, RESPFILE keywords to either “NONE”or to the values given on the command line.

specgroup spectrumset=myspec.ds arfset=myarf.ds rmfset=myrmf.ds

will set the arf and rmf filenames as given and will set BACKFILE to

NONE.

These are needed for XSPEC 12 to load the file.

XMMEPICSOC

Richard SaxtonBackground, Operations & Calibration (BOC) meeting

Madrid, 23/03/10-24/03/10

CAL file issues

We read the energy resolution and bad channel ranges from an XMM CCF for the MOS, PN and RGS instruments. Task should be usable for other instruments, e.g. Chandra. There is a need for a mission-independent calibration file format !

XMMEPICSOC

Richard SaxtonBackground, Operations & Calibration (BOC) meeting

Madrid, 23/03/10-24/03/10

• Elliptical parameterisation of the 2-d stacked PSFs. Released in SAS 10.

• Parameters stored in XRTn_XPSF_010.CCF files

- King fn: core radius, slope, ellipticity

- as function of (instrument), energy, off-axis angle

• Phi (azimuthal) dependence = rotation of ellipse

ELLIPTICAL King function

0°45° 90°

XMMEPICSOC

Richard SaxtonBackground, Operations & Calibration (BOC) meeting

Madrid, 23/03/10-24/03/10

• Elliptical parameterisation of the 2-d stacked PSFs. Released in SAS 10.

• 1-D PSF ‘ELLBETA’ mode – King profile (r0, alpha), ellipticity – fn(instr, E, theta) + Gaussian (FWHM, norm) – used in ARF generation/spectral fitting for elliptical regions.

• Phi (azimuthal) dependence = rotation of ellipse

• ---------------------------------------------------------------

• eregionanalyse calculates the optimum ellipse

• arfgen recognises the optimum ellipse region and calculates the encircled-energy correction using the ELLBETA model. A non-optimum ellipse uses the ‘HIGH’ accuracy PSF model.

• These tasks packaged up in xmmselect “OGIP spectral products’

Producing optimum ellipse

XMMEPICSOC

Richard SaxtonBackground, Operations & Calibration (BOC) meeting

Madrid, 23/03/10-24/03/10

efluxerefluxer spectrumset=mysrc.ds arfset=mysrc.arf rrmset=mysrc.rmf

backgndset=mybgd.ds fluxedset=mysrc_fluxed.ds