jeremy j. drake, herman l. marshall and the cxc ... · chandra calibration status jeremy j. drake,...

CHANDRA CALIBRATION STATUSJEREMY J. DRAKE, HERMAN L. MARSHALL AND THE CXC CALIBRATION GROUP

Chandra Calibration

XMM-Newton

I A C H E C2 0 1 9

Chandra Calibration

XMM-Newton

I A C H E C2 0 1 9

Great waves IACHEC Buoys us through calibrating

To bring our fish home

CHANDRA CALIBRATION STATUS

REMINDER OF CHANDRA HARDWARE COMPONENTS

ACIS HRC

CHANDRA CALIBRATION UPDATE

OUTLINE

▸ Point Spread Function

▸ Secular trend or worsening PSF in HRC-S

▸ ACIS

▸ mid-chip gain droop; contamination

▸ HRC-S,I

▸ QE decline; gain decline

▸ HETG

▸ 0th to 1st order relative calibration

POINT SPREAD FUNCTION


HRC PSF (V. KASHYAP, P. ZHAO, D. JERIUS)

▸ The HRC-I PSF has remained stable over the mission

▸ HRC-S PSF is steadily increasing in width and appears about 10% larger now that at the start of the mission

▸ Degradation is possibly related to decline in gain

▸ Intrinsic detector psf?

▸ Degap drift?

Vinay Kashyap


PSF MONITORING

85% EE

50% EE

30% EE

10% EE

70% EE

ADVANCED CCD IMAGING SPECTROMETER (ACIS)

I0 I1

I2 I3


MID-CHIP GAIN DROOP (T. GAETZ) ECS


MID-CHIP GAIN DROOP FIX (T. GAETZ)

I0 I1

I2 I3

Al K

I3

~30 eV gain drop

Before correction


MID-CHIP GAIN DROOP FIX (T. GAETZ)

I0 I1

I2 I3

Al K

ACIS-I3 Mid-Chip “gain droop” (w/ trial gain, resp)chipy vs. chipx1.49 keV

-0.4 -0.3 -0.2 -0.1 0 0.1 0.2

T. Gaetz (CXC/SAO) Chandra ACIS-I3 Mid-Chip Gain Droop IACHEC 2019 11 / 12

I3

After correction

ACIS-I3 Mid-Chip “gain droop” (w/ trial gain, resp)chipy vs. chipx0.64 keV (coarse grid)

-0.8 -0.7 -0.6 -0.5 -0.4 -0.3 -0.2 -0.1 0 0.1

T. Gaetz (CXC/SAO) Chandra ACIS-I3 Mid-Chip Gain Droop IACHEC 2019 11 / 12


MID-CHIP GAIN DROOP (T. GAETZ)

I0 I1

I2 I3

Mn K (lower S/N)

I3

After correction


PROGRESS WITH TIME-DEPENDENT GAIN (R. DURHAM, P. PLUCINSKY)


FILTER CONTAMINATION LAYER (A, BOGDAN, H. MARSHALL, P. PLUCINSKY ET AL)

0.1

1

0.5 1 3

cts

s-1 k

eV-1

Energy (keV)

200020052010201320162019

ACIS-SA1795

0

0.5

1

1.5

2

2.5

3

3.5

2000 2005 2010 2015

τ (E

= 0

.66

keV)

Date

A1795 -- ACIS-IE0102 -- ACIS-I





0

0.5

1

1.5

2

2.5

3

3.5

2000 2005 2010 2015

τ (E

= 0

.66

keV)

Date

A1795 -- ACIS-SE0102 -- ACIS-S

HIGH RESOLUTION CAMERA

2000.0 2002.5 2005.0 2007.5 2010.0 2012.5 2015.0 2017.5

0.85

0.90

0.95

1.00

1.05

Rat

e/

2008

.5

HZ 43: HRC/LETG Count Rates

HRC-I: 0th

HRC-S: 0th

HRC-S: -1st: 57-157

HRC-S: +1st: 69-173

2002.5 2005.0 2007.5 2010.0 2012.5 2015.0 2017.5Date

0.7

0.8

0.9

1.0

1.1

1.2

Rat

e/

2008

.5HIGH RESOLUTION CAMERA

QUANTUM EFFICIENCY DECLINE (P. RATZLAFF, J. DRAKE, V. KASHYAP, B. WARGELIN)

HRC-S High voltage increase



HRC-S Gain Decline



HZ43 LETG+HRC-S Empirical QEU Corrections

60 80 100 120 140 160 1800.75

0.80

0.85

0.90

0.95

1.00

1.05

1.10

1.15

Obs/

Pre

d

20708: 2018-05-27 - 2018-09-26

60 80 100 120 140 160 1800.75

0.80

0.85

0.90

0.95

1.00

1.05

1.10

1.1520706: 2018-09-26 -

-ve 1st order+ve 1st order

Corrections expressed relative to 2.35%/yr grey decline

HIGH RESOLUTION CAMERA - SPECTROSCOPY


Gain-related problems for PI-base background filtering

2012 2013 2014 2015 2016 2017 2018 2019Date

0.4

0.5

0.6

0.7

0.8

0.9

1.0

Rat

e:Filte

red

/U

nfilter

ed

167A < TG MLAM < 169A

169A < TG MLAM < 171A

171A < TG MLAM < 173A

173A < TG MLAM < 175A

• +ve order long wavelength source signal now same PI as lowest PI background events

• PI-base bg filtering removes significant signal

HIGH ENERGY TRANSMISSION GRATING (HETG)

0TH:1ST ORDER CALIBRATION (N. SCHULZ)

▸ Use multiple HETG+ACIS-S sources in M31 that are not piled up in 0th order to calibrate 0th relative to first order

▸ Simultaneous diskbb+powerlaw model fits

M31centerwithChandraHETG:

R.Supperetal.2001,A&A,373,63:SoEdiffuseemissionatM31bulge(~1039ergs-1)

S.eleetal.2011,A&A,534,55:Shireyetal.2001,A&A,365,L195:Powerlawindex=-1.82,NH=6.7x1020cm-2

Needtomodeldispersedso-backgroundinChandraHETGspectra!!!



Simultaneousmodelfitstoboth:zero-orderandHETGfirstorderSourcemodel:columndensity*(diskblackbody+powerlaw)kTandindex.ed/fixed,normaliza.onsvariableHETG:applyaverageM31diffusebackgroundandallowfor20%varia.ons

2×10−3 4×10−3 6×10−3 8×10−3

2×10

−34×

10−3

6×10

−38×

10−3

CCD norm: diskbb

HET

G n

orm

: dis

kbb

5×10−5 10−4 1.5×10−4

5×10

−510

−41.

5×10

−4

CCD norm: powerlaw

HET

G n

orm

: pow

erla

w

ThesmallsymbolsareindividualsourcesThelargefilledcircleistheall6sourcestackedresult.

Individual sources

Stacked spectrum

Agreement to 8% from individual sources, 2-3% from stacked

0th

1st

0th

CHANDRA CALIBRATION UPDATE

SUMMARY

▸ Chandra calibration challenges are as a result of aging and decline of instrument performance and accumulation of contamination on ACIS

▸ HRC-S PSF is increasing and this behavior is not currently understood.

▸ ACIS mid-chip gain droop calibration coming shortly

▸ ACIS contamination model is being regularly updated: slower rate of increase seen last year is not born out in newer data.

▸ Continuing HRC-S QE secular changes are being calibrated (HV increase on HRC-S is only a matter of time).

▸ HETG 0th vs 1st order calibration is looking good - few % - at energies above 1.5 keV; need more data for lower E.

SUPPLEMENTARY MATERIAL


PSF MONITORING: WARM HRMA



5 10 15 20

1010

0M31 stack[m31stack], 3441 ks, MEG + HEG

Counts/bin

Wavelength(A)

Stackedsourcespectrum

StackedM31diffusebackgroundspectrum

jeremy j. drake, herman l. marshall and the cxc ... · chandra calibration status jeremy j. drake,...

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