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CrossCalibration between XMMNewton and Chandra
Herman L. Marshall Chandra Xray Center, MIT Kavli Institute


Overview
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XMM/Chandra Crosscalibration telecons: · continuing monthly meetings · formed web pages comparing fits Began effort to crosscal formally 2 · Goal: achieve = 1 for all cal sources · prototyping methodology continues Attending meetings for joint cal discussions · this EPIC cal meeting · multiobservatory crosscal meeting in June (Reykjavik) Implementing crosscal with Suzaku in May
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May 5, 2006

HLM -- XMM/Chandra


XMM/Chandra Blazar Observations to Date

From http://space.mit.edu/ASC/calib/crosscal/ May 5, 2006
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From XMM team: XMMSOCCALTN0052 (Stuhlinger et al. 2006) May 5, 2006
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From XMM team: XMMSOCCALTN0052 (Stuhlinger et al. 2006) May 5, 2006
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Comparing XMM and Chandra
XMM web pages
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Fit results internal for now

data page: http://xmm.esac.esa.int/~xmmdoc/EPIC_CROSSC

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XMM report: XMMSOCCALTN0052 (Stuhlinger et al. 2006) CXC web page: http://space.mit.edu/ASC/calib/crosscal/ XMM whiteboard used for some reports Results agree generally but not within errors

May 5, 2006

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Sample XMMChandra Comparison (XMM side)
Comparing indices is difficult

From http://xmm.esac.esa.int/~xmmdoc/EPIC_CROSSCAL/cross_cal_data.php

May 5, 2006

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Sample XMMChandra Comparison (HETGS side)

From http://space.mit.edu/ASC/calib/crosscal/

May 5, 2006

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Sample XMMChandra Comparison (HETGS side)

From http://space.mit.edu/ASC/calib/crosscal/

May 5, 2006

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Caveats: XMMChandra Comparison (HETGS side)
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Variability: affects one observation of PKS 2155304 (but not 1H 1426+428 and 3C 273) Different models used by ESAC and CXC
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broken PL vs. smooth PL HETGS fits without 2PL

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Residuals: compare for complete story Bowtie: models extrapolated to low SNR Have not achieved
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= 1 for bright sources
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May 5, 2006

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Formalizing CrossCalibration
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Goal: achieve
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/ = 1 for all cal sources
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Premise: Users want

/ = 1 if model fits

Local adjustments, Ajn g(x; j) > overdetermined system, reducing 2 Ajn depend on instrument n,
j

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fixed
n

Compare instruments by comparing Aj Minimize where
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Method proposed: Use penalty function
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May 5, 2006

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Formalizing CrossCalibration
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Test cases · Mk 421: bright, 100 ks · XTE J1118+480: bright 24 ks g(x) = Gaussian, = 2е, 2е apart, starting at 1е Results · OK amplitudes (figure) 2 · min / · separately: 2.20, 1.14 · jointly: 2.62, 1.48 Conclusions · Need more Gaussians · or different basis functions · or adaptive functions ...
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Work in Progress
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Joint web page population · Coordinate modeling between projects · Process all Chandra cal data uniformly · Will add analysis of 1E 010272 Developing joint analysis methodology · Primary goals may not be achievable soon · Must define secondary goals Setting up crosscal with XMM and Suzaku · Target: PKS 2155304 · This week · Will use LETG/HRC Chandra grating observations of PKS 2155 · Aug `06 -- independent of XMM, Suzaku · To be used for Chandra internal crosscal
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May 5, 2006

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Overview
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Formed web pages comparing fits General but not statistical agreement
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Results need revision and analysis

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Prototyping formal crosscal methodology Attending meetings for joint cal discussions
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Improves approach to data handling Refines analysis and methodology

Implementing crosscal with Suzaku in May
May 5, 2006
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