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Chandra X-Ray Observatory CXC
Paul Plucinsky EPIC Cal April 20071
1.1. ACIS Calibration:ACIS Calibration: Recent Updates, Recent Updates,
Planned Updates, &Planned Updates, & Future IssuesFuture Issues
2.2. E0102: Joint Fits with ACIS S3, E0102: Joint Fits with ACIS S3,
MOS1/2 & MOS1/2 & pnpn
Paul Plucinsky, Joseph Paul Plucinsky, Joseph DePasqualeDePasquale,, & &
Steve SnowdenSteve Snowden
Chandra X-Ray Observatory CXC
Paul Plucinsky EPIC Cal April 20072
1. Recent Updates to the ACIS Calibration1. Recent Updates to the ACIS Calibration
• BI CCD CTI correction for -120 C (S3 & S1), need to have CIAO
3.4 also to apply the correction, BI CTI correction is now part of the
standard data processing
• Effective area correction around the Si K edge, ~4 % at 1.8 keV
• FI CCD ``dead area’’ correction to account for the area lost on
average in each frame to cosmic rays, 2.5-4.0% as a function of row
CALDB 3.3.0 released on 15 December 2006
Chandra X-Ray Observatory CXC
Paul Plucinsky EPIC Cal April 20073
Planned Update: CTI Correction for Graded Mode for FI Planned Update: CTI Correction for Graded Mode for FI CCDsCCDs
• Faint mode CTI correction adjusts the PH of each pixel in the 3x3
event island
• In Graded mode, only have x, y position of event, grade, and
summed PH
• Use grade and summed PH to determine the most likely charge
distribution based on ``average’’ images
• Use this information in an Graded mode CTI correction
Mn-K flight grade 8 (left split) for S2
Bottom 256 rows Top 256 rows
Vikhlinin (SAO)
Chandra X-Ray Observatory CXC
Paul Plucinsky EPIC Cal April 20074
Map ofMap of Good and Bad Grades Good and Bad Grades
Vikhlinin (SAO)
33 of 256 flight
grades are included
in the ASCA
G02346 grades
Create average
images for each
of these 33
grades for
multiple energies
Chandra X-Ray Observatory CXC
Paul Plucinsky EPIC Cal April 20075
Comparison of Graded Mode and Faint Mode CTI CorrectionComparison of Graded Mode and Faint Mode CTI Correction
Posson-
Brown
(SAO)
Graded mode
CTI correction
provides most
of the benefit
of the Faint
mode correction
For FI
CCDs only !
Chandra X-Ray Observatory CXC
Paul Plucinsky EPIC Cal April 20076
Continuous Clocking Mode Calibration Continuous Clocking Mode Calibration
Edgar (SAO)
In CC mode:
- row-to-row transfer
time is different so the
effects of CTI are
different
-- don’t know the y
position of the events,
but for some
observations you know
the y position of the
source
External Calibration Source: No CTI correction applied
Chandra X-Ray Observatory CXC
Paul Plucinsky EPIC Cal April 20077
Update on Contaminant BuildupUpdate on Contaminant Buildup
Data:
Grant (MIT)
Model:
O’Dell &
Tennant
(MSFC)
Chandra X-Ray Observatory CXC
Paul Plucinsky EPIC Cal April 20078
Optical DepthOptical Depth ComparisonComparison
C-K Marshall (MIT)
inferred optical
depth at 700 eV
ECS Grant (MIT)
Mn L
E0102 DePasquale
(SAO) OVIII Ly-a
Chandra X-Ray Observatory CXC
Paul Plucinsky EPIC Cal April 20079
Future Issues: Focal Plane Operating TemperatureFuture Issues: Focal Plane Operating Temperature
• current operating temperature is -119.7 C
• as the mission has progressed, the frequency and magnitude of
deviations from the desired temperature have increased
• it might become necessary to operate at a higher temperature, significant
impact for the FI CCDs
Chandra X-Ray Observatory CXC
Paul Plucinsky EPIC Cal April 200710
2. E0102: Gratuitous Pretty Pictures of E01022. E0102: Gratuitous Pretty Pictures of E0102
S3 Summed Data ~100 S3 Summed Data ~100 ksks RGS Spectrum (Pollock 2006)RGS Spectrum (Pollock 2006)
Objective:Objective: develop a spectral model which can be used by RGS, HETG,
EPIC & ACIS, etc.
Chandra X-Ray Observatory CXC
Paul Plucinsky EPIC Cal April 200711
Application of RGS Spectral ModelApplication of RGS Spectral Model Dewey (MIT)
Use RGS
spectral model
Construct a
spatial model
Compare
simulation to
data
Bright lines
agree well
Chandra X-Ray Observatory CXC
Paul Plucinsky EPIC Cal April 200712
MEG minus
1st order
Simulation
Comparison
KS test
OVIII OVIINeIXNeXMgXI
Chandra X-Ray Observatory CXC
Paul Plucinsky EPIC Cal April 200713
MEG plus
1st order
Simulation
Comparison
KS test
MgXI NeX NeIX OVIII OVII
Chandra X-Ray Observatory CXC
Paul Plucinsky EPIC Cal April 200714
Joint Fit with Pollock Model to ACIS S3, MOS1/2 & Joint Fit with Pollock Model to ACIS S3, MOS1/2 & pnpn
SAS 7.0, latest CCF
Many thanks
Steve !!
No fit, adopt
Pollock
RGS model
Brems kT = 0.36
keV
CCD spectra prefer
a harder continuum
NH=5.36e20
Line Es and
widths frozen,
Norms free
Chandra X-Ray Observatory CXC
Paul Plucinsky EPIC Cal April 200715
Joint Fit with Pollock Model to ACIS S3, MOS1/2 & Joint Fit with Pollock Model to ACIS S3, MOS1/2 & pnpn
Fit, Brems
kT =0.60 keV
NH=5.36e20
Line Es &
widths
frozen,
norms free
Chandra X-Ray Observatory CXC
Paul Plucinsky EPIC Cal April 200716
Individual Fit with Pollock Model to ACIS S3Individual Fit with Pollock Model to ACIS S3
Fit, Brems
kT =0.60 keV
NH=5.36e20
Line Es &
widths
frozen,
norms free
Chandra X-Ray Observatory CXC
Paul Plucinsky EPIC Cal April 200717
Individual Fit with Pollock Model toIndividual Fit with Pollock Model to MOS1MOS1
Fit, Brems
kT =0.60 keV
NH=5.36e20
Line Es &
widths
frozen,
norms free
Chandra X-Ray Observatory CXC
Paul Plucinsky EPIC Cal April 200718
Individual Fit with Pollock Model toIndividual Fit with Pollock Model to MOS1: MOS1: Ne Ne lines freelines free
Fit, Brems
kT =0.65 keV
NH=5.36e20
Ne Line Es
free,
widths
frozen,
norms free
Chandra X-Ray Observatory CXC
Paul Plucinsky EPIC Cal April 200719
Individual Fit with Pollock Model to Individual Fit with Pollock Model to pnpn
Fit, Brems
kT =0.40 keV
NH=5.36e20
Line Es
frozen,
widths
frozen,
norms free
Chandra X-Ray Observatory CXC
Paul Plucinsky EPIC Cal April 200720
Where Do We Go From Here ?Where Do We Go From Here ?
• Dewey analysis needs to be updated with latest response files for
HRMA/ACIS/HETG
• Line-based analysis needs to be updated with the latest response
files for HRMA/HETG/ACIS
• RGS data need to be re-analyzed with new background model for
RGS
• RGS and HETG teams agree on a model well before the IACHEC
meeting in California
• ACIS, MOS, and pn use the new model to fit the CCD spectra
Chandra X-Ray Observatory CXC
Paul Plucinsky EPIC Cal April 200721
LetLet’’s Agree on a Model !!!!!!!s Agree on a Model !!!!!!!
Purpose: to improve the low-energy response model of ACIS, MOS
and pn CCD instruments
1) RGS and HETG agree on flux of bright lines
2) RGS and HETG compromise on existence of weak lines
3) RGS and HETG agree on widths for the lines
4) Select a continuum model and absorption
5) HETG team must analyze second epoch observations of E0102
6) Fit ACIS, MOS, and pn with the same model