EPIC Calibration Meeting, MadridEPIC Calibration Meeting, Madrid Experience with combined FeExperience with combined Fe5555/Vela SNR calibration/Vela SNR calibration K. Dennerl, 2010 March K. Dennerl, 2010 March 2323
Experience with combined FeExperience with combined Fe5555 / Vela SNR calibration / Vela SNR calibration
Madrid, 2010 March 23-24Madrid, 2010 March 23-24
EPIC Calibration & Operations Meeting
NRCO 81
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
Internal calibration source onboard XMM-Newton / EPIC-pn
Al-K Mn-K
EPIC Calibration Meeting, MadridEPIC Calibration Meeting, Madrid Experience with combined FeExperience with combined Fe5555/Vela SNR calibration/Vela SNR calibration K. Dennerl, 2010 March K. Dennerl, 2010 March 2323
30 ks in 2000
210 ks in 2008
390 ks in 2010
1.4 Ms in 2015
30 ks in 2000
210 ks in 2008
390 ks in 2010
1.4 Ms in 201510 ks
30 ks
half-life of Fe55: 2.7 yr
activity in 2010:
7.7% of activity in 2000
Motivation: decay of the internal calibration source
EPIC Calibration Meeting, MadridEPIC Calibration Meeting, Madrid Experience with combined FeExperience with combined Fe5555/Vela SNR calibration/Vela SNR calibration K. Dennerl, 2010 March K. Dennerl, 2010 March 2323
NR
CO
81
EPIC Calibration Meeting, MadridEPIC Calibration Meeting, Madrid Experience with combined FeExperience with combined Fe5555/Vela SNR calibration/Vela SNR calibration K. Dennerl, 2010 March K. Dennerl, 2010 March 2323
NR
CO
81 0) offset map calculation
1) cal-closed
2) thin (Vela SNR)
3) cal-thin (Vela SNR)
EPIC Calibration Meeting, MadridEPIC Calibration Meeting, Madrid Experience with combined FeExperience with combined Fe5555/Vela SNR calibration/Vela SNR calibration K. Dennerl, 2010 March K. Dennerl, 2010 March 2323
NR
CO
81
EPIC Calibration Meeting, MadridEPIC Calibration Meeting, Madrid Experience with combined FeExperience with combined Fe5555/Vela SNR calibration/Vela SNR calibration K. Dennerl, 2010 March K. Dennerl, 2010 March 2323
EPIC Calibration Meeting, MadridEPIC Calibration Meeting, Madrid Experience with combined FeExperience with combined Fe5555/Vela SNR calibration/Vela SNR calibration K. Dennerl, 2010 March K. Dennerl, 2010 March 2323
Strategy:
1. start with regular Fe55 exposure
2. perform regular Vela observation
3. finish with Vela + Fe55 observation
Questions:
1. does Vela disturb the calibration exposure ?
2. does the internal calibration source disturb the Vela observation ?
same offset map used in all exposures,
all exposures performed in a contiguous mode, within one revolution
sequence: cal-closed thin cal-thin
NRCO 81
EPIC Calibration Meeting, MadridEPIC Calibration Meeting, Madrid Experience with combined FeExperience with combined Fe5555/Vela SNR calibration/Vela SNR calibration K. Dennerl, 2010 March K. Dennerl, 2010 March 2323
calclosed: 2009-10-24T22:35:25.790 2009-10-25T09:46:49.729thin: 2009-10-25T09:54:02.576 2009-10-25T21:14:05.294calthin: 2009-10-25T21:21:09.369 2009-10-26T08:53:37.906
red: 0.3 - 0.7 keV, 0 – 25 cts/pxgreen: 1.2 – 1.8 keV, 0 – 5 cts/pxblue: 5.0 – 7.0 keV, 0 – 4 cps/px
Spectra and images, derived from singles
cal-closed thin cal-thin
EPIC Calibration Meeting, MadridEPIC Calibration Meeting, Madrid Experience with combined FeExperience with combined Fe5555/Vela SNR calibration/Vela SNR calibration K. Dennerl, 2010 March K. Dennerl, 2010 March 2323
Does the presence of the Vela SNR (and the different filter wheel position) affect the calibration measurements with the internal Fe55 source ?
comparison cal-closed cal-thin
EPIC Calibration Meeting, MadridEPIC Calibration Meeting, Madrid Experience with combined FeExperience with combined Fe5555/Vela SNR calibration/Vela SNR calibration K. Dennerl, 2010 March K. Dennerl, 2010 March 2323
Method: compare line position in 30 subfields* for every quadrant
*with sufficient photon statistics
errors determined
from the spread of
the line energies
EPIC Calibration Meeting, MadridEPIC Calibration Meeting, Madrid Experience with combined FeExperience with combined Fe5555/Vela SNR calibration/Vela SNR calibration K. Dennerl, 2010 March K. Dennerl, 2010 March 2323
cal-closed, quadrant 0 cal-thin (Vela SNR), quadrant 0
1179.1 ± 2.31178.5 ± 3.1 + 0.6 adu
all s
ing
les
EPIC Calibration Meeting, MadridEPIC Calibration Meeting, Madrid Experience with combined FeExperience with combined Fe5555/Vela SNR calibration/Vela SNR calibration K. Dennerl, 2010 March K. Dennerl, 2010 March 2323
cal-closed, quadrant 1 cal-thin (Vela SNR), quadrant 1
1178.5 ± 1.9
all s
ing
les
1179.6 ± 1.7 + 1.1 adu
EPIC Calibration Meeting, MadridEPIC Calibration Meeting, Madrid Experience with combined FeExperience with combined Fe5555/Vela SNR calibration/Vela SNR calibration K. Dennerl, 2010 March K. Dennerl, 2010 March 2323
cal-closed, quadrant 2 cal-thin (Vela SNR), quadrant 2
1178.3 ± 1.6
all s
ing
les
1178.8 ± 1.4 + 0.5 adu
EPIC Calibration Meeting, MadridEPIC Calibration Meeting, Madrid Experience with combined FeExperience with combined Fe5555/Vela SNR calibration/Vela SNR calibration K. Dennerl, 2010 March K. Dennerl, 2010 March 2323
cal-closed, quadrant 3 cal-thin (Vela SNR), quadrant 3
1177.9 ± 3.2
all s
ing
les
1178.0 ± 2.2 + 0.1 adu
EPIC Calibration Meeting, MadridEPIC Calibration Meeting, Madrid Experience with combined FeExperience with combined Fe5555/Vela SNR calibration/Vela SNR calibration K. Dennerl, 2010 March K. Dennerl, 2010 March 2323
Does the presence of the Vela SNR (and the different filter wheel position) affect the calibration measurements with the internal Fe55 source ?
comparison cal-closed cal-thin
quadrant 0: +0.6 adu
quadrant 1: +1.1 adu
quadrant 2: +0.5 adu
quadrant 3: +0.1 adu
quadrant 0: +0.6 adu
quadrant 1: +1.1 adu
quadrant 2: +0.5 adu
quadrant 3: +0.1 adu
yes, systematic shift of Mn-Kα to higher energies:
EPIC Calibration Meeting, MadridEPIC Calibration Meeting, Madrid Experience with combined FeExperience with combined Fe5555/Vela SNR calibration/Vela SNR calibration K. Dennerl, 2010 March K. Dennerl, 2010 March 2323
Does the presence of the Vela SNR (and the different filter wheel position) affect the calibration measurements with the internal Fe55 source ?
comparison cal-closed cal-thin
yes, systematic shift of Mn-Kα to higher energies:
quadrant 0: +0.6 adu
quadrant 1: +1.1 adu
quadrant 2: +0.5 adu
quadrant 3: +0.1 adu
quadrant 0: +0.6 adu
quadrant 1: +1.1 adu
quadrant 2: +0.5 adu
quadrant 3: +0.1 adu
Main difference: presence of additional
photons in cal-thin
could an inappropriate correction of
precursor induced CTI changes cause the
shift ?
same analysis with first singles..
EPIC Calibration Meeting, MadridEPIC Calibration Meeting, Madrid Experience with combined FeExperience with combined Fe5555/Vela SNR calibration/Vela SNR calibration K. Dennerl, 2010 March K. Dennerl, 2010 March 2323
cal-closed, quadrant 0 cal-thin (Vela SNR), quadrant 0
all f
irst
sin
gle
s
1178.5 ± 3.1 1179.2 ± 2.3 + 0.7 adu
EPIC Calibration Meeting, MadridEPIC Calibration Meeting, Madrid Experience with combined FeExperience with combined Fe5555/Vela SNR calibration/Vela SNR calibration K. Dennerl, 2010 March K. Dennerl, 2010 March 2323
cal-closed, quadrant 1 cal-thin (Vela SNR), quadrant 1
all f
irst
sin
gle
s
1179.7 ± 1.7 + 1.2 adu1178.5 ± 1.8
EPIC Calibration Meeting, MadridEPIC Calibration Meeting, Madrid Experience with combined FeExperience with combined Fe5555/Vela SNR calibration/Vela SNR calibration K. Dennerl, 2010 March K. Dennerl, 2010 March 2323
cal-closed, quadrant 2 cal-thin (Vela SNR), quadrant 2
all f
irst
sin
gle
s
1178.9 ± 1.3 + 0.5 adu1178.4 ± 1.6
EPIC Calibration Meeting, MadridEPIC Calibration Meeting, Madrid Experience with combined FeExperience with combined Fe5555/Vela SNR calibration/Vela SNR calibration K. Dennerl, 2010 March K. Dennerl, 2010 March 2323
cal-closed, quadrant 3 cal-thin (Vela SNR), quadrant 3
all f
irst
sin
gle
s
1178.4 ± 3.1 + 0.1 adu1178.3 ± 2.3
EPIC Calibration Meeting, MadridEPIC Calibration Meeting, Madrid Experience with combined FeExperience with combined Fe5555/Vela SNR calibration/Vela SNR calibration K. Dennerl, 2010 March K. Dennerl, 2010 March 2323
Does the presence of the Vela SNR (and the different filter wheel position) affect the calibration measurements with the internal Fe55 source ?
comparison cal-closed cal-thin
yes, systematic shift of Mn-Kα to higher energies:
quadrant 0: +0.6 adu
quadrant 1: +1.1 adu
quadrant 2: +0.5 adu
quadrant 3: +0.1 adu
quadrant 0: +0.6 adu
quadrant 1: +1.1 adu
quadrant 2: +0.5 adu
quadrant 3: +0.1 adu
singles
Main difference: presence of additional
photons in cal-thin:
could an inappropriate correction of
precursor induced CTI changes cause the
shift ?
same analysis with first singles..
Main difference: presence of additional
photons in cal-thin:
could an inappropriate correction of
precursor induced CTI changes cause the
shift ?
same analysis with first singles.. energy shift not
caused by (visible)
precursors
quadrant 0: +0.7 adu
quadrant 1: +1.2 adu
quadrant 2: +0.5 adu
quadrant 3: +0.1 adu
quadrant 0: +0.7 adu
quadrant 1: +1.2 adu
quadrant 2: +0.5 adu
quadrant 3: +0.1 adu
first singles
EPIC Calibration Meeting, MadridEPIC Calibration Meeting, Madrid Experience with combined FeExperience with combined Fe5555/Vela SNR calibration/Vela SNR calibration K. Dennerl, 2010 March K. Dennerl, 2010 March 2323
Does the presence of the Vela SNR (and the different filter wheel position) affect the calibration measurements with the internal Fe55 source ?
The systematic energy shift of Mn-Kα when the Vela SNR is in the FOV is not due to imperfect modeling of (visible) precursors.
Could this be a temporal effect due to, e.g., temperature changes ?
Splitting the exposures into pieces of the same length (~600s) and monitoring the line energy (from the whole detector) with XSPEC..
EPIC Calibration Meeting, MadridEPIC Calibration Meeting, Madrid Experience with combined FeExperience with combined Fe5555/Vela SNR calibration/Vela SNR calibration K. Dennerl, 2010 March K. Dennerl, 2010 March 2323
Does the presence of the Vela SNR (and the different filter wheel position) affect the calibration measurements with the internal Fe55 source ?
Splitting the exposures into pieces of the same length (~600s) and monitoring the line energy (from the whole detector) with XSPEC..
cal-closed, all singles cal-thin, all singles
1σ errors determined from Δχ2 = +1
Mn-K
EPIC Calibration Meeting, MadridEPIC Calibration Meeting, Madrid Experience with combined FeExperience with combined Fe5555/Vela SNR calibration/Vela SNR calibration K. Dennerl, 2010 March K. Dennerl, 2010 March 2323
Does the presence of the Vela SNR (and the different filter wheel position) affect the calibration measurements with the internal Fe55 source ?
Splitting the exposures into pieces of the same length (~600s) and monitoring the line energy (from the whole detector) with XSPEC..
cal-closed, first singles cal-thin, first singles
1σ errors determined from Δχ2 = +1
Mn-K
EPIC Calibration Meeting, MadridEPIC Calibration Meeting, Madrid Experience with combined FeExperience with combined Fe5555/Vela SNR calibration/Vela SNR calibration K. Dennerl, 2010 March K. Dennerl, 2010 March 2323
cal-closed, first singles cal-thin, first singles
cal-closed, all singles cal-thin, all singles
the energy shift happens between the observations
EPIC Calibration Meeting, MadridEPIC Calibration Meeting, Madrid Experience with combined FeExperience with combined Fe5555/Vela SNR calibration/Vela SNR calibration K. Dennerl, 2010 March K. Dennerl, 2010 March 2323
an energy shift happens also at Al-K
cal-closed, all singles cal-thin, all singles
Does the presence of the Vela SNR (and the different filter wheel position) affect the calibration measurements with the internal Fe55 source ?
Splitting the exposures into pieces of the same length (~600s) and monitoring the line energy (from the whole detector) with XSPEC..
1σ errors determined from Δχ2 = +1
Al-K
EPIC Calibration Meeting, MadridEPIC Calibration Meeting, Madrid Experience with combined FeExperience with combined Fe5555/Vela SNR calibration/Vela SNR calibration K. Dennerl, 2010 March K. Dennerl, 2010 March 2323
cal-closed, all singles
spectrum over the full detector and the whole time interval
cal-thin, all singles
spectrum over the full detector and the whole time interval
E = (5.8945 +/ - 0.0005) keV E = (5.8995 +/ - 0.0005) keV
from total exposures:from total exposures:
+ (5.0 ± 0.7) eV
EPIC Calibration Meeting, MadridEPIC Calibration Meeting, Madrid Experience with combined FeExperience with combined Fe5555/Vela SNR calibration/Vela SNR calibration K. Dennerl, 2010 March K. Dennerl, 2010 March 2323
cal-closed, all singles
spectrum over the full detector and the whole time interval
cal-thin, all singles
spectrum over the full detector and the whole time interval
from total exposures:from total exposures:
E = (1.4920 +/- 0.0004) keV E = (1.4965 +/- 0.0007) keV+ (4.5 ± 0.8) eV
EPIC Calibration Meeting, MadridEPIC Calibration Meeting, Madrid Experience with combined FeExperience with combined Fe5555/Vela SNR calibration/Vela SNR calibration K. Dennerl, 2010 March K. Dennerl, 2010 March 2323
Does the presence of the internal Fe55 source affect the calibration measurements with the Vela SNR ?
comparison thin cal-thin
EPIC Calibration Meeting, MadridEPIC Calibration Meeting, Madrid Experience with combined FeExperience with combined Fe5555/Vela SNR calibration/Vela SNR calibration K. Dennerl, 2010 March K. Dennerl, 2010 March 2323
thin, all singles
spectrum over the full detector and the whole time interval
cal-thin, all singles
spectrum over the full detector and the whole time interval
from total exposures:from total exposures:
E = ( 0.5862 +/- 0.0004) keV E = (0.5865 +/- 0.0004) keV
+ (0.3 ± 0.6) eV
EPIC Calibration Meeting, MadridEPIC Calibration Meeting, Madrid Experience with combined FeExperience with combined Fe5555/Vela SNR calibration/Vela SNR calibration K. Dennerl, 2010 March K. Dennerl, 2010 March 2323
no energy shift happens at OVII between thin and cal-thin
thin, all singles cal-thin, all singles
Splitting the exposures into pieces of the same length (~600s) and monitoring the line energy (from the whole detector) with XSPEC..
1σ errors determined from Δχ2 = +1
Does the presence of the internal Fe55 source affect the calibration measurements with the Vela SNR ?OVII
EPIC Calibration Meeting, MadridEPIC Calibration Meeting, Madrid Experience with combined FeExperience with combined Fe5555/Vela SNR calibration/Vela SNR calibration K. Dennerl, 2010 March K. Dennerl, 2010 March 2323
E = (0.5862 +/- 0.0004) keV E = (0.5865 +/- 0.0004) keV
E = (1.4920 +/- 0.0004) keV E = (1.4965 +/- 0.0007) keVE = (1.493 +/- 0.002) keV
E = (5.8945 +/ - 0.0005) keV E = (5.8995 +/ - 0.0005) keV
Summary: line energies (all singles, whole detector)
cal-closed thin cal-thin
+ (0.3 ± 0.6) eV
+ (4.5 ± 0.8) eV
+ (5.0 ± 0.7) eV
EPIC Calibration Meeting, MadridEPIC Calibration Meeting, Madrid Experience with combined FeExperience with combined Fe5555/Vela SNR calibration/Vela SNR calibration K. Dennerl, 2010 March K. Dennerl, 2010 March 2323
cal-closed thin cal-thin
Summary of NRCO 81
Changing from cal-closed to cal-thin, with the Vela SNR in the FOV, increases the energies of Al-K and Mn-K by ~ 5 eV.
No change in the line energy is observed at the OVII emission from the Vela SNR, if the detector is additionally irradiated with the internal calibration source.
EPIC Calibration Meeting, MadridEPIC Calibration Meeting, Madrid Experience with combined FeExperience with combined Fe5555/Vela SNR calibration/Vela SNR calibration K. Dennerl, 2010 March K. Dennerl, 2010 March 2323
Conclusions from NRCO 81
The change observed between cal-closed and cal-thin is not caused by deficiencies in the code for the precursor correction.
It is, however, possible that photons/particles penetrating the thin filter release additional charge in the CCDs which is below the low energy threshold and thus not transmitted, but still capable of reducing the charge transfer losses by trap saturation.
Independent of its origin, the fact that an energy shift is observed between the cal-closed and cal-thin observation indicates that cal-thin conditions may be more appropriate for exposures with the internal calibration source.
Cal-thin (and probably also cal-medium and cal-thick) observations of suitable targets offer promising opportunities for future calibration exposures. The Vela SNR is definitively suited for such a purpose.
EPIC Calibration Meeting, MadridEPIC Calibration Meeting, Madrid Experience with combined FeExperience with combined Fe5555/Vela SNR calibration/Vela SNR calibration K. Dennerl, 2010 March K. Dennerl, 2010 March 2323
Experience with combined FeExperience with combined Fe5555 / Vela SNR calibration / Vela SNR calibration
Madrid, 2010 March 23-24Madrid, 2010 March 23-24
EPIC Calibration & Operations Meeting
NRCO 81