experience with combined fe 55 / tycho snr calibration

EPIC Calibration Meeting, MallorcaEPIC Calibration Meeting, Mallorca Experience with combined FeExperience with combined Fe5555/Tycho SNR /Tycho SNR calibrationcalibration

K. Dennerl, 2008 April 8K. Dennerl, 2008 April 8

Experience with combined FeExperience with combined Fe5555 / Tycho SNR calibration / Tycho SNR calibration

Mallorca, Spain, 2008 April 7 - 8Mallorca, Spain, 2008 April 7 - 8

EPIC Calibration & Operations Meeting

NRCO 71



Internal calibration source onboard XMM-Newton / EPIC-pn

Al-K Mn-K



30 ks in 2000

210 ks in 2008

10 ks

30 ks



General plan:

1. start with ‘normal’ Tycho observation

2. add the internal calibration source

3. finish with ‘normal’ calclosed observation

Unfortunately, this sequence was scheduled as three independent observations, performed in a non-contiguous mode

superposition with short-term changes in the absolute energy scale

no firm conclusions about potential changes of the absolute energy scale possible

however: general idea about ‘calopen’ observations


does the internal calibration source disturb the Tycho observation ?

does Tycho disturb the calclosed measurement ?



1) Tycho FF Medium, 2007-12-30 / 19:55 – 2007-12-31 / 03:37, 27 ks




2) Tycho FF Cal Medium, 2008-01-01 / 19:58 – 2008-01-02 / 09:59, 50 ks




3) Calclosed, 2008-01-03 / 01:06 – 2008-01-03 / 08:11, 25 ks




1) Tycho FF Medium, 2007-12-30 / 19:55 – 2007-12-31 / 03:37, 27 ks



2) Tycho FF Cal Medium, 2008-01-01 / 19:58 – 2008-01-02 / 09:59, 50 ks



3) Calclosed, 2008-01-03 / 01:06 – 2008-01-03 / 08:11, 25 ks



5.75 6.00 keV

adu

Narrow-line images at Mn-K: 5.70 – 6.05 keV

ΔE = 350 eV



Narrow-line images at Mn-K: 5.70 – 6.05 keV

Tycho CalClosed Tycho + CalClosed

scaled to the same exposure time ΔE = 0.35 keV



ΔE = 0.35 keV ΔE = 1.0 keV

ΔE = 2.0 keV ΔE = 5.0 keV

Tycho + CalClosed

all energy bands centered on Mn-K



1.25 1.50 1.75 keV

adu

Narrow-line images at Al-K: 1.375 – 1.575 keV

ΔE = 200 eV



Narrow-line images at Al-K: 1.375 – 1.575 keV

Tycho CalClosed Tycho + CalClosed

scaled to the same exposure time ΔE = 0.20 keV



calclosed



Tycho



Tycho + calclosed



calc

lose

d

Mn-K



Tyc

ho +

cal

clos

ed

Mn-K



calc

lose

d

Al-K



Tyc

ho +

cal

clos

ed

Al-K



25 macro pixels,

20-29 singles per macro pixel

CTI determination: Illustration of the Template Cross Correlation method (EPIC pn)



calclosed

CTI



Tycho + calclosed

CTI




Tycho + calclosed seems ok for Mn-K, but not for Al-K

Tycho better suited for LW than for FF

Calclosed & LW no useful combination

are there celestial calibration targets which are better suited for a combined Fe55 exposure ?



Vela SNR



Vela SNR (62 ks)



calclosed (25 ks)



Vela SNR + calclosed (scaled to 62 ks)




Vela + calclosed might be an interesting alternative:

• the parts of the Vela SNR covered by the FOV are similarly extended as the internal calibration source

• the X-ray surface brightness of the Vela SNR is similar to that of the internal calibration source

• the X-ray spectrum of the Vela SNR is almost complementary to that of the internal calibration source

But the Al-K region would need to be checked in detail..

Vela + calclosed might be an interesting alternative:

• the parts of the Vela SNR covered by the FOV are similarly extended as the internal calibration source

• the X-ray surface brightness of the Vela SNR is similar to that of the internal calibration source

• the X-ray spectrum of the Vela SNR is almost complementary to that of the internal calibration source

But the Al-K region would need to be checked in detail..

experience with combined fe 55 / tycho snr calibration

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