EPIC Calibration Meeting, Mallorca Low energy calibration with the Vela SNR K. Dennerl, 2009 March 31 Low energy calibration with the Vela SNR Mallorca,

EPIC Calibration Meeting, MallorcaEPIC Calibration Meeting, Mallorca Low energy calibration with the Vela SNRLow energy calibration with the Vela SNR K. Dennerl, 2009 March K. Dennerl, 2009 March 3131

Low energy calibration with the Vela SNRLow energy calibration with the Vela SNR

Mallorca, Spain, 2009 March 31 – April 1Mallorca, Spain, 2009 March 31 – April 1

EPIC Calibration & Operations Meeting


2001- 2007: 12 long FF observations,

several with different pointing coordinates and roll angles

fairly homogeneous illumination of the detector

Vela SNR: extended source with bright OVII emission

excellent calibration source


Monitoring the absolute energy scale @ 0.57 keV with the Vela SNR:


Monitoring the absolute energy scale @ 1.49 keV with the internal calibration source:


Vela SNR

internal calibration source

Comparison: trends at 0.57 keV and 1.49 keV

0.57 keV

1.49 keV


0.574 keV (Vela SNR)

1.486 keV (Al-K, scaled)

Comparison: trends at 0.57 keV and 1.49 keV


Internal calibration source onboard XMM-Newton / EPIC-pn

Al-K Mn-K

inhomogeneous irradiation at Mn-K, illumination of quadrant 3 very poor


0.40 – 0.74 keV

total exposure (after removing times of background flares):

~300 ks

photon map (singles)

exposure corrected map

Superposition of all Vela SNR observations in

FF mode

exposure map

maximum: 172 singles/pixel


0.40 – 0.74 keV

photon map

(singles)

adaptive binning into subareas of similar signal

Spatial properties of the absolute energy scale


vertical binning according to response matrices

horizontal binning adaptively, criterion: ~5000 single events within 400 – 740 eV (above background)

422 fields

Spatial properties of the absolute energy scale


removal of periods of enhanced background

correction for local energy shifts due to errors in the offset map (epreject)

correction for energy shifts between the individual observations

correction for out-of-time events

Preparations for a joint fit


Spectral model used ( E = 0.43 – 0.74 keV )

all line energies and widths coupled to reference line (O VII r)

relative line fluxes of O VII triplet fixed

continuum approximated by powerlow

8 fit parameters


Spectral model used ( E = 0.43 – 0.74 keV )



result:result:

energy scale spatially homogeneous within ±10 eV

however, also evidence for systematic shifts in a ring-like pattern



removal of periods of enhanced background

correction for local energy shifts due to errors in the offset map (epreject)

correction for energy shifts between the individual observations

correction for out-of-time events different binning, different spectral models

Checks for stability and reproducibility of the result






EPIC-Cal Meeting, Tübingen, Germany, 2003 Feb 3-5

9.874 keV (Ge-K)

1.186 keV (Ge-L)



9.874 keV (Ge-K)

1.186 keV (Ge-L)


Printed Circuit Board



9.874 keV (Ge-K)

1.186 keV (Ge-L)




EPIC-Cal Meeting, VILSPA, Spain, 2004 Mar 23-24


EPIC-Cal Meeting, Mallorca, Spain, 2009 March 31 – April 1


Comparison with Mn-K


Comparison with Mn-K


Mn-K


Correcting spatial inhomogeneities of the absolute energy scale

1. offsets in the energy scale due to errors in the offset map

2. column gain variations after launch

3. CTI changes due to residual light through the ventilation hole

20 adu image, rev 546

EPIC-Cal Meeting, MPE-Garching, Germany, 2006 May 4


EPIC-Cal Meeting, Mallorca, Spain, 2007 Nov 6-7






EPIC-Cal Meeting, Mallorca, Spain, 2007 Nov 6-7






EPIC-Cal Meeting, Mallorca, Spain, 2009 March 31 – April 1






Low energy calibration with the Vela SNRLow energy calibration with the Vela SNR

Mallorca, Spain, 2009 March 31 – April 1Mallorca, Spain, 2009 March 31 – April 1

EPIC Calibration & Operations Meeting

Documents

EPIC Calibration Meeting, Mallorca Low energy calibration with the Vela SNR K. Dennerl, 2009 March 31 Low energy calibration with the Vela SNR Mallorca,