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Chandra X-Ray Observatory

CXC

1. ACIS Calibration: Recent Updates, Planned Updates, & Future Issues 2. E0102: Joint Fits with ACIS S3, MOS1/2 & pn

Paul Plucinsky, Joseph DePasquale, & Steve Snowden
Paul Plucinsky 1

EPIC Cal April 2007


Chandra X-Ray Observatory
1. Recent Updates to the ACIS Calibration
CALDB 3.3.0 released on 15 December 2006

CXC

· 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

Paul Plucinsky

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EPIC Cal April 2007


Chandra X-Ray Observatory
Planned Update: CTI Correction for Graded Mode for FI CCDs · 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

CXC

Mn-K flight grade 8 (left split) for S2 Bottom 256 rows Top 256 rows

Vikhlinin (SAO)

Paul Plucinsky

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EPIC Cal April 2007


Chandra X-Ray Observatory
Map of Good and Bad Grades

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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

Paul Plucinsky

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EPIC Cal April 2007


CXC Comparison of Graded Mode and Faint Mode CTI Correction

Chandra X-Ray Observatory

PossonBrown (SAO) Graded mode CTI correction provides most of the benefit o f th e F a i n t mode correction Fo r FI CCDs only !
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Paul Plucinsky

EPIC Cal April 2007


Chandra X-Ray Observatory
Continuous Clocking Mode Calibration
External Calibration Source: No CTI correction applied

CXC

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

Paul Plucinsky

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EPIC Cal April 2007


Chandra X-Ray Observatory
Update on Contaminant Buildup

CXC

Data: Grant (MIT) Model: O'Dell & Tennant (M S F C )

Paul Plucinsky

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EPIC Cal April 2007


Chandra X-Ray Observatory
Optical Depth Comparison

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C-K Marshall (MIT) inferred optical depth at 700 eV ECS Grant (MIT) Mn L E0102 DePasquale (SAO) OVIII Ly-a

Paul Plucinsky

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EPIC Cal April 2007


Chandra X-Ray Observatory
Future Issues: Focal Plane Operating Temperature

CXC

· 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

Paul Plucinsky

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EPIC Cal April 2007


Chandra X-Ray Observatory
2. E0102: Gratuitous Pretty Pictures of E0102
S3 Summed Data ~100 ks

CXC

RGS Spectrum (Pollock 2006)

Objective: develop a spectral model which can be used by RGS, HETG, EPIC & ACIS, etc.
Paul Plucinsky 10

EPIC Cal April 2007


Chandra X-Ray Observatory
Application of RGS Spectral Model
Dewey (MIT)

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Use RGS spectral model Construct a spatial model Compare simulation to d a ta Bright lines agree well

Paul Plucinsky

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EPIC Cal April 2007


Chandra X-Ray Observatory
MEG minus 1st order

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MgXI
Simulation

NeX NeIX

OVIII

OVII

Comparison

KS test

Paul Plucinsky

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EPIC Cal April 2007


Chandra X-Ray Observatory
MEG plus 1st order

CXC

MgXI
Simulation

NeX NeIX

OVIII

OVII

Comparison

KS test

Paul Plucinsky

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EPIC Cal April 2007


Chandra X-Ray Observatory
Joint Fit with Pollock Model to ACIS S3, MOS1/2 & pn

CXC

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

Paul Plucinsky

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EPIC Cal April 2007


Chandra X-Ray Observatory
Joint Fit with Pollock Model to ACIS S3, MOS1/2 & pn

CXC

Fit, Brems kT =0.60 keV NH=5.36e20 Line Es & widths frozen, norms free

Paul Plucinsky

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EPIC Cal April 2007


Chandra X-Ray Observatory
Individual Fit with Pollock Model to ACIS S3

CXC

Fit, Brems kT =0.60 keV NH=5.36e20 Line Es & widths frozen, norms free

Paul Plucinsky

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EPIC Cal April 2007


Chandra X-Ray Observatory
Individual Fit with Pollock Model to MOS1

CXC

Fit, Brems kT =0.60 keV NH=5.36e20 Line Es & widths frozen, norms free

Paul Plucinsky

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EPIC Cal April 2007


Chandra X-Ray Observatory

CXC

Individual Fit with Pollock Model to MOS1: Ne lines free
Fit, Brems kT =0.65 keV NH=5.36e20 Ne Line Es free, widths frozen, norms free

Paul Plucinsky

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EPIC Cal April 2007


Chandra X-Ray Observatory
Individual Fit with Pollock Model to pn

CXC

Fit, Brems kT =0.40 keV NH=5.36e20 Line Es frozen, widths frozen, norms free

Paul Plucinsky

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EPIC Cal April 2007


Chandra X-Ray Observatory
Where Do We Go From Here ?

CXC

· 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

Paul Plucinsky

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EPIC Cal April 2007


Chandra X-Ray Observatory
Let's Agree on a Model !!!!!!!
Purpose: to improve the low-energy response model of ACIS, MOS and pn CCD instruments

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1 2 3 4 5 6

) ) ) ) ) )

RGS and HETG agree on flux of bright lines RGS and HETG compromise on existence of weak lines RGS and HETG agree on widths for the lines Select a continuum model and absorption HETG team must analyze second epoch observations of E0102 Fit ACIS, MOS, and pn with the same model

Paul Plucinsky

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EPIC Cal April 2007