using standard candle x-ray spectra to calibrate the strongly variable mos response · 2010. 3....
TRANSCRIPT
XMMEPICMOS
Steve Sembay ([email protected])Madrid 23/03/10
Using Standard Candle X-ray spectra to calibrate the strongly variable MOS response
“Calibration or just a mathematical exercise?”
Ties together three themes....
1) Computationally quick phenomenological RMF model2) Derivation of RMF model parameters via optimisation algorithm3) Use of “standard candle” spectra to constrain RMF solution
Wednesday, 24 March 2010
XMMEPICMOS
Steve Sembay ([email protected])Madrid 23/03/10
Di1 = N1 Σ Rij Aj1 Sj1
Di2 = N2 Σ Rij Aj2 Sj2
...
Din = Nn Σ Rij Ajn Sjn
Adjust parameters (using tnmin algorithm) which define rmf, R, and global normalisations, N, to minimise
Σ ((Oi - Di)/δOi)2 + Σ ((Oi - Di)/δOi)2 + ... + Σ ((Oi - Di)/δOi)2
Basic Scheme: For a given epoch and spatial region...
Wednesday, 24 March 2010
XMMEPICMOS
Steve Sembay ([email protected])Madrid 23/03/10
Previous Phenomenological Model: The VRMF Model
Blue Wing: Gaussian
Red Wing: Voigt Function
= Gaussian convolved with a Lorentian.
Dampening factor = 0 (Gaussian) > 0 (Lorentz-like)
Fit to Orsay Data
Wednesday, 24 March 2010
XMMEPICMOS
Steve Sembay ([email protected])Madrid 23/03/10
Frac in (red+orange) = 0.48Frac in orange = 0.52
Frac in (red+orange) = 0.53Frac in orange = 0.55
Frac in (red+orange) = 0.44Frac in orange = 0.23
Out of patch “wings (15”-40”)”
“core (0”-15”)”
New model adds a flat “shelf”
Evaluation time for 2400 x 2400array (5eV binning) ~ 3.5 seconds in IDL
Wednesday, 24 March 2010
XMMEPICMOS
Steve Sembay ([email protected])Madrid 23/03/10
Resolution = α1 + β1 x sqrt(e0)
Dampen= α2 exp( -(e0-β2) / γ2) for β2 > e0 = α2 β2 <= e0
i.e. tends to zero for large e0 (more Gaussian)
Parameters which define redistribution matrix, R
Wednesday, 24 March 2010
XMMEPICMOS
Steve Sembay ([email protected])Madrid 23/03/10
FLoss = α3 exp( -(e0-β3) / γ3) for β3 > e0 = α3 β3 <= e0
FLoss = FLoss_peak + FLoss_shelf
FLoss_peak= α4 exp( -(e0-β4) / γ4) for β4 > e0 = α4 β4 <= e0
EEloss/e0 = α5 for e0 < 300 eV = α6 for e0 > 400 eV
Wednesday, 24 March 2010
XMMEPICMOS
Steve Sembay ([email protected])Madrid 23/03/10
Total parameters = 13
Not counting parameters giving intensityof silicon fluorescence and escape peaks(fixed to previous calibration)
Time to derive one solution for a given set of input spectra ~ 3 to 6 hours.
Wednesday, 24 March 2010
XMMEPICMOS
Steve Sembay ([email protected])Madrid 23/03/10
“Standard Candle” Spectral Models
1) The white dwarf CAL83
2) The isolated neutron star RXJ 1856
3) The O star Zeta Puppis
4) The SNR 1ES0102
Wednesday, 24 March 2010
XMMEPICMOS
Steve Sembay ([email protected])Madrid 23/03/10
“Standard Candle” Spectral Models
1) The white dwarf CAL83
See next slides
2) The isolated neutron star RXJ 1856
phabs * (bb + bb) (V. Burwtiz pn model)
3) The O star Zeta Puppis
Frank’s RGS model
4) The SNR 1ES0102
The IACHEC WG model (Plucinsky et al.)
Wednesday, 24 March 2010
XMMEPICMOS
Steve Sembay ([email protected])Madrid 23/03/10
Lantz, T, et al. (2005) ApJ, 619, 517
Non-LTE Model atmosphere derivedfrom LETG and RGS (Rev 0068)
Model file converted to atable model
nH = 6.5 x 1020 cm-2 (abund wilm)
0
5×10!18
10!17
norm
alize
d cou
nts s!
1 Hz!1
Black (RGS1) Red (RGS2)CAL83 RGS Rev 0068
20 30 40 50 60 700
1
2
3
ratio
Wavelength (Å)
0
5×10!18
10!17
norm
alize
d cou
nts s!
1 Hz!1
Black (old rmf) Red (new rmf)CAL 83 MOS1 rev 0068
20 30 40 50 60 700.5
1
1.5
ratio
Wavelength (Å)
Wednesday, 24 March 2010
XMMEPICMOS
Steve Sembay ([email protected])Madrid 23/03/10
Lantz, T, et al. (2005) ApJ, 619, 517
Non-LTE Model atmosphere derivedfrom LETG and RGS (Rev 0068)
Model file converted to atable model
nH = 6.5 x 1020 cm-2 (abund wilm)
0
2×10−17
4×10−17
norm
alize
d cou
nts s−
1 Hz−1
Black (PN Thin) Red (PN Med)CAL 83 PN Rev 0068
20 30 40 50 60 700.5
1
1.5
ratio
Wavelength (Å)
Use instead best fit descriptive modelto PN = phabs * bb (abund wilm)
nH = 1.11 x 1021 cm-2
kT = 0.034 keV
Wednesday, 24 March 2010
XMMEPICMOS
Steve Sembay ([email protected])Madrid 23/03/10
Epoch 1: Revolution 0065 - 0156
“Pre-Patch”
Standards:
1E0102 (Rev 65)Cal 83 (Rev 68)Puppis (Rev 156)
Test Sources:
MS0737 (BL Lac) (Rev 63)3C 273 (Blazar) (Rev 94)
Wednesday, 24 March 2010
XMMEPICMOS
Steve Sembay ([email protected])Madrid 23/03/10
1.2931.2931.2511.482
1.2501.2541.2261.354
1.2221.1981.2341.750
1.1901.1651.2211.510
0
1
2
3no
rmal
ized
coun
ts s
−1 k
eV−1
Black (thin) Red (med) Green (thick)CAL 83 MOS1 Rev 0068 (current rmf)
0.2 0.5
−20
0
20
sign(
data−m
odel
) × !
"2
Energy (keV)
0
1
2
3
norm
alize
d co
unts
s−1
keV
−1
Black (thin) Red (med) Green (thick)CAL 83 MOS1 Rev 0068 (new rmf)
0.2 0.5
−20
0
20
sign(
data−m
odel
) × !
"2
Energy (keV)
0
1
2
3
norm
alize
d co
unts
s−1
keV
−1
Black (thin) Red (med) Green (thick)CAL 83 MOS2 Rev 0068 (current rmf)
0.2 0.5
−20
0
20
sign(
data−m
odel
) × !
"2
Energy (keV)
0
1
2
3
norm
alize
d co
unts
s−1
keV
−1
Black (thin) Red (med) Green (thick)CAL 83 MOS2 Rev 0068 (new rmf)
0.2 0.5
−20
0
20
sign(
data−m
odel
) × !
"2
Energy (keV)
Black (thin) Red (med) Green (thick)
M1 M2
Wednesday, 24 March 2010
XMMEPICMOS
Steve Sembay ([email protected])Madrid 23/03/10
0.972 - 0.9731.993 - 1.422
0.944 - 0.9462.235 - 1.697
1.063 - 1.0612.253 - 2.441
1.106 - 1.1081.859 - 1.567
0
5
10
norm
alize
d co
unts
s−1
keV
−1
Black (current RMF) Red (new RMF)1E0102 MOS2 Rev 0065
10.2 0.5
−20
0
20
sign(
data−m
odel
) × !
"2
Energy (keV)
0
1
2
3
norm
alize
d co
unts
s−1
keV
−1
Black (current RMF) Red (new RMF)Puppis MOS2 Rev 0156
10.2 0.5
−20
0
20
sign(
data−m
odel
) × !
"2
Energy (keV)
0
1
2
3
norm
alize
d co
unts
s−1
keV
−1Black (current RMF) Red (new RMF)
Puppis MOS1 Rev 0156
10.2 0.5
−20
0
20
sign(
data−m
odel
) × !
"2
Energy (keV)
0
5
10
norm
alize
d co
unts
s−1
keV
−1
Black (current RMF) Red (new RMF)1E0102 MOS1 Rev 0065
10.2 0.5
−20
0
20
sign(
data−m
odel
) × !
"2
Energy (keV)
Wednesday, 24 March 2010
XMMEPICMOS
Steve Sembay ([email protected])Madrid 23/03/10
1.0531.129
1.1411.094
1.1471.093
1.0571.135
0.01
0.1
1
norm
alize
d co
unts
s−1
keV
−1Black (PN) Red (MOS1 old RMF)
m0737 PN/MOS1 Rev 0063
10.2 0.5 2 5−20
−10
0
10
20
sign(
data−m
odel
) × !
"2
Energy (keV)
0.01
0.1
1
norm
alize
d co
unts
s−1
keV
−1
Black (PN) Red (MOS2 old RMF)m0737 PN/MOS2 Rev 0063
10.5 2 5−20
−10
0
10
20
sign(
data−m
odel
) × !
"2
Energy (keV)
0.01
0.1
1
norm
alize
d co
unts
s−1
keV
−1
Black (PN) Red (MOS2 new RMF)m0737 PN/MOS2 Rev 0063
10.5 2 5−20
−10
0
10
20
sign(
data−m
odel
) × !
"2
Energy (keV)
0.01
0.1
1
norm
alize
d co
unts
s−1
keV
−1
Black (PN) Red (MOS1 new RMF)m0737 PN/MOS1 Rev 0063
10.2 0.5 2 5−20
−10
0
10
20
sign(
data−m
odel
) × !
"2
Energy (keV)
Wednesday, 24 March 2010
XMMEPICMOS
Steve Sembay ([email protected])Madrid 23/03/10
1.0531.033
1.0201.001
1.0251.037
1.0601.042
0.1
1
10no
rmal
ized
coun
ts s
−1 k
eV−1
Black (PN) Red (MOS1 old RMF)3c273 PN/MOS1 Rev 0094
10.2 0.5 2 5−20
−10
0
10
20
sign(
data−m
odel
) × !
"2
Energy (keV)
0.1
1
10
norm
alize
d co
unts
s−1
keV
−1
Black (PN) Red (MOS1 old RMF)3c273 PN/MOS1 Rev 0094
10.2 0.5 2 5−20
−10
0
10
20
sign(
data−m
odel
) × !
"2
Energy (keV)
Black (PN) Red (MOS1 new RMF)
0.1
1
10
norm
alize
d co
unts
s−1
keV
−1
Black (PN) Red (MOS1 old RMF)3c273 PN/MOS2 Rev 0094
10.2 0.5 2 5−20
−10
0
10
20
sign(
data−m
odel
) × !
"2
Energy (keV)
0.1
1
10
norm
alize
d co
unts
s−1
keV
−1
Black (PN) Red (MOS1 old RMF)3c273 PN/MOS2 Rev 0094
10.2 0.5 2 5−20
−10
0
10
20
sign(
data−m
odel
) × !
"2
Energy (keV)
Black (PN) Red (MOS1 new RMF)
Wednesday, 24 March 2010
XMMEPICMOS
Steve Sembay ([email protected])Madrid 23/03/10
Epoch 2: Revolution 0795-0900
On-axis, “patch affected”
Standards:
RXJ1856 (Rev 878)Puppis (Rev 795)1E0102 (Rev 894-900)
Test Sources:
H1426 (BL Lac) (Rev 939)
Wednesday, 24 March 2010
XMMEPICMOS
Steve Sembay ([email protected])Madrid 23/03/10
1.116 - 1.0891.425 - 1.287
1.089 - 1.0751.312 - 1.139
0.920 - 1.0408.152 - 1.506
0.990 - 0.98616.64 - 2.458
0
2
4
6
norm
alize
d co
unts
s−1
keV
−1Black (current RMF) Red (new RMF)
RXJ1856 MOS1 Rev 0878 Thin
0.1 0.2 0.5
−20
0
20
sign(
data−m
odel
) × !
"2
Energy (keV)
0
2
4
6
8
norm
alize
d co
unts
s−1
keV
−1
Black (current RMF) Red (new RMF)RXJ1856 MOS2 Rev 0878 Thin
0.1 0.2 0.5
−20
0
20
sign(
data−m
odel
) × !
"2
Energy (keV)
Black (current RMF) Red (new RMF)
0
1
2
norm
alize
d co
unts
s−1
keV
−1
Black (current RMF) Red (new RMF)Puppis MOS1 Rev 0795
10.2 0.5
−20
0
20
sign(
data−m
odel
) × !
"2
Energy (keV)
0
1
2
norm
alize
d co
unts
s−1
keV
−1
Black (current RMF) Red (new RMF)Puppis MOS1 Rev 0795
10.2 0.5
−20
0
20
sign(
data−m
odel
) × !
"2
Energy (keV)
“Core”
Wednesday, 24 March 2010
XMMEPICMOS
Steve Sembay ([email protected])Madrid 23/03/10
1.073 - 1.0711.298 - 1.216
1.029 - 1.0351.298 - 1.214
0.817 - 0.9063.994 - 1.058
0.962 - 0.9852.846 - 1.344
0
0.5
1
1.5
2
norm
alize
d co
unts
s−1
keV
−1Black (current RMF) Red (new RMF)
RXJ1856 MOS1 Rev 0878 Thin
0.1 0.2 0.5
−20
0
20
sign(
data−m
odel
) × !
"2
Energy (keV)
0
0.5
1
1.5
2
norm
alize
d co
unts
s−1
keV
−1
Black (current RMF) Red (new RMF)RXJ1856 MOS2 Rev 0878 Thin
0.1 0.2 0.5
−20
0
20
sign(
data−m
odel
) × !
"2
Energy (keV)
0
0.2
0.4
0.6
norm
alize
d co
unts
s−1
keV
−1
Black (current RMF) Red (new RMF)Puppis MOS1 Rev 0795
10.2 0.5
−20
0
20
sign(
data−m
odel
) × !
"2
Energy (keV)
0
0.2
0.4
0.6
norm
alize
d co
unts
s−1
keV
−1
Black (current RMF) Red (new RMF)Puppis MOS1 Rev 0795
10.2 0.5
−20
0
20
sign(
data−m
odel
) × !
"2
Energy (keV)
“Wings”
Wednesday, 24 March 2010
XMMEPICMOS
Steve Sembay ([email protected])Madrid 23/03/10
6.582 - 1.8364.728 - 1.713
1.325 - 1.173 2.060 - 2.121
0
1
2
norm
alize
d co
unts
s−1
keV
−1Black (current RMF) Red (new RMF)
1E0102 MOS1 Rev 0894−0900
10.2 0.5
−20
0
20
sign(
data−m
odel
) × !
"2
Energy (keV)
0
1
2
norm
alize
d co
unts
s−1
keV
−1
Black (current RMF) Red (new RMF)1E0102 MOS2 Rev 0894−0900
10.2 0.5
−20
0
20
sign(
data−m
odel
) × !
"2
Energy (keV)
0
2
4
6
norm
alize
d co
unts
s−1
keV
−1
Black (current RMF) Red (new RMF)1E0102 MOS1 Rev 0894−0900
10.2 0.5
−20
0
20
sign(
data−m
odel
) × !
"2
Energy (keV)
0
2
4
6
norm
alize
d co
unts
s−1
keV
−1
Black (current RMF) Red (new RMF)1E0102 MOS2 Rev 0894−0900
10.2 0.5
−20
0
20
sign(
data−m
odel
) × !
"2
Energy (keV)
“Core”
“Wings”
Wednesday, 24 March 2010
XMMEPICMOS
Steve Sembay ([email protected])Madrid 23/03/10
1.0330.987
1.0001.059
0.9961.065
1.0361.010
0.01
0.1
1
norm
alize
d co
unts
s−1
keV
−1Black (PN) Red (MOS1 old RMF)
H1426 PN/MOS1 Rev 0939
10.2 0.5 2 5−20
−10
0
10
20
sign(
data−m
odel
) × !
"2
Energy (keV)
0.01
0.1
1
norm
alize
d co
unts
s−1
keV
−1
Black (PN) Red (MOS1 new RMF)H1426 PN/MOS1 Rev 0939
10.2 0.5 2 5−20
−10
0
10
20
sign(
data−m
odel
) × !
"2
Energy (keV)
0.01
0.1
1
norm
alize
d co
unts
s−1
keV
−1
Black (PN) Red (MOS2 old RMF)H1426 PN/MOS2 Rev 0939
10.2 0.5 2 5−20
−10
0
10
20
sign(
data−m
odel
) × !
"2
Energy (keV)
0.01
0.1
1
norm
alize
d co
unts
s−1
keV
−1
Black (PN) Red (MOS2 new RMF)H1426 PN/MOS2 Rev 0939
10.2 0.5 2 5−20
−10
0
10
20
sign(
data−m
odel
) × !
"2
Energy (keV)
Wednesday, 24 March 2010
XMMEPICMOS
Steve Sembay ([email protected])Madrid 23/03/10
Epoch 3: Revolution 1265-1335
Off axis (Still on CCD1)
Standards:
1E0102 (Rev 1265)RXJ1856 (Rev 1335)
Test Sources:
REJ 2248 (AGN) (Rev 1361)
Wednesday, 24 March 2010
XMMEPICMOS
Steve Sembay ([email protected])Madrid 23/03/10
0.878 - 0.8833.624 - 1.590
0.908 - 0.9133.380 - 2.139
0.902 - 1.03634.74 - 1.324
0.874 - 0.95925.24 - 1.503
0
2
4
6
8
norm
alize
d co
unts
s−1
keV
−1
Black (current RMF) Red (new RMF)1E0102 MOS1 Rev 1265
10.2 0.5−40
−20
0
20
40
sign(
data−m
odel
) × !
"2
Energy (keV)
0
2
4
6
8
norm
alize
d co
unts
s−1
keV
−1
Black (current RMF) Red (new RMF)1E0102 MOS2 Rev 1265
10.2 0.5
−20
0
20
sign(
data−m
odel
) × !
"2
Energy (keV)
0
5
10
norm
alize
d co
unts
s−1
keV
−1Black (current RMF) Red (new RMF)
RXJ1856 MOS1 Rev 1335
0.1 10.2 0.5
−20
0
20
sign(
data−m
odel
) × !
"2
Energy (keV)
0
5
10
norm
alize
d co
unts
s−1
keV
−1
Black (current RMF) Red (new RMF)RXJ1856 MOS2 Rev 1335
0.1 10.2 0.5
−20
0
20
sign(
data−m
odel
) × !
"2
Energy (keV)
Wednesday, 24 March 2010
XMMEPICMOS
Steve Sembay ([email protected])Madrid 23/03/10
1.0341.254
1.0531.166
1.0791.225
1.0601.186
0.01
0.1
1
norm
alize
d co
unts
s−1
keV
−1Black (PN) Red (MOS1 old RMF)
REJ2248 PN/MOS1 Rev 1361
10.2 0.5 2 5−20
−10
0
10
20
sign(
data−m
odel
) × !
"2
Energy (keV)
0.01
0.1
1
norm
alize
d co
unts
s−1
keV
−1
Black (PN) Red (MOS1 new RMF)REJ2248 PN/MOS1 Rev 1361
10.2 0.5 2 5−20
−10
0
10
20
sign(
data−m
odel
) × !
"2
Energy (keV)
0.01
0.1
1
norm
alize
d co
unts
s−1
keV
−1
Black (PN) Red (MOS2 old RMF)REJ2248 PN/MOS2 Rev 1361
10.2 0.5 2 5−20
−10
0
10
20
sign(
data−m
odel
) × !
"2
Energy (keV)
0.01
0.1
1
norm
alize
d co
unts
s−1
keV
−1
Black (PN) Red (MOS2 new RMF)REJ2248 PN/MOS2 Rev 1361
10.2 0.5 2 5−20
−10
0
10
20
sign(
data−m
odel
) × !
"2
Energy (keV)
Wednesday, 24 March 2010
XMMEPICMOS
Steve Sembay ([email protected])Madrid 23/03/10
Epoch 4: Revolution 1616-1636
On-axis, “patch affected”
Standards:
RXJ1856 (Rev 1616)1E0102 (Rev 1636)
Test Sources:
3C 273 (BL Lac) (Rev 1649)
Wednesday, 24 March 2010
XMMEPICMOS
Steve Sembay ([email protected])Madrid 23/03/10
1.560 - 1.8741.955 - 1.770
0.821 - 0.97518.13 - 2.495
0.892 - 0.89428.09 - 7.000
0
1
2
3
norm
alize
d co
unts
s−1
keV
−1
Black (current RMF) Red (new RMF)1E0102 MOS1 Rev 1636
10.2 0.5
−20
0
20
sign(
data−m
odel
) × !
"2
Energy (keV)
0
1
2
3
norm
alize
d co
unts
s−1
keV
−1
Black (current RMF) Red (new RMF)1E0102 MOS2 Rev 1636
10.2 0.5
−20
0
20
sign(
data−m
odel
) × !
"2
Energy (keV)
0
2
4
6no
rmal
ized
coun
ts s
−1 k
eV−1
Black (current RMF) Red (new RMF)RXJ1856 MOS1 Rev 1616
0.1 0.2 0.5
−20
0
20
sign(
data−m
odel
) × !
"2
Energy (keV)
0
2
4
6
norm
alize
d co
unts
s−1
keV
−1
Black (current RMF) Red (new RMF)RXJ1856 MOS2 Rev 1616
0.1 0.2 0.5
−20
0
20
sign(
data−m
odel
) × !
"2
Energy (keV)
“Core”
Wednesday, 24 March 2010
XMMEPICMOS
Steve Sembay ([email protected])Madrid 23/03/10
3.647 - 1.5043.509 - 1.614
0.733 - 0.9355.390 - 0.992
0.907 - 0.9382.964 - 2.015
0
2
4
norm
alize
d co
unts
s−1
keV
−1
Black (current RMF) Red (new RMF)1E0102 MOS1 Rev 1636
10.2 0.5
−20
0
20
sign(
data−m
odel
) × !
"2
Energy (keV)
0
2
4
6
norm
alize
d co
unts
s−1
keV
−1
Black (current RMF) Red (new RMF)1E0102 MOS2 Rev 1636
10.2 0.5
−20
0
20
sign(
data−m
odel
) × !
"2
Energy (keV)
0
0.5
1
1.5
2no
rmal
ized
coun
ts s
−1 k
eV−1
Black (current RMF) Red (new RMF)RXJ1856 MOS1 Rev 1616
0.1 0.2 0.5
−20
0
20
sign(
data−m
odel
) × !
"2
Energy (keV)
0
0.5
1
1.5
2
norm
alize
d co
unts
s−1
keV
−1
Black (current RMF) Red (new RMF)RXJ1856 MOS2 Rev 1616
0.1 0.2 0.5
−20
0
20
sign(
data−m
odel
) × !
"2
Energy (keV)
“Wings”
Wednesday, 24 March 2010
XMMEPICMOS
Steve Sembay ([email protected])Madrid 23/03/10
1.0290.970
0.9590.953
0.9421.003
1.0271.024
0.1
1
10no
rmal
ized
coun
ts s
−1 k
eV−1
Black (PN) Red (MOS1 old RMF)3c273 PN/MOS1 Rev 1649
10.2 0.5 2 5−20
−10
0
10
20
sign(
data−m
odel
) × !
"2
Energy (keV)
0.1
1
10
norm
alize
d co
unts
s−1
keV
−1
Black (PN) Red (MOS1 new RMF)3c273 PN/MOS2 Rev 1649
10.2 0.5 2 5−20
−10
0
10
20
sign(
data−m
odel
) × !
"2
Energy (keV)
0.1
1
10
norm
alize
d co
unts
s−1
keV
−1
Black (PN) Red (MOS1 old RMF)3c273 PN/MOS2 Rev 1649
10.2 0.5 2 5−20
−10
0
10
20
sign(
data−m
odel
) × !
"2
Energy (keV)
0.1
1
10
norm
alize
d co
unts
s−1
keV
−1
Black (PN) Red (MOS1 new RMF)3c273 PN/MOS2 Rev 1649
10.2 0.5 2 5−20
−10
0
10
20
sign(
data−m
odel
) × !
"2
Energy (keV)
Wednesday, 24 March 2010
XMMEPICMOS
Steve Sembay ([email protected])Madrid 23/03/10
Conclusions:
1) The MOS has a strongly variable on-axis response and needsto calibrated against “something” given that we have no physical model of the response which explains the changes we see.
2) The best we can do is probably pick models of astrophysical sources for which there is some consensus within the communityof what these models should be....i.e. so-called “standard candles”
3) We have a mathematical model of the response which looks togive a good fit to a chosen subset of these “standard candles”
4) If we adopt this route we need to make the ALL the “standard candle” models publically available to the community (i.e. XSPEC xcm files) with documentation as to how these models were derived.
Wednesday, 24 March 2010