Table 4: HRMA PRF/Encircled Energy/Effective Areaa
1
)
E)
2.
2.1 Encircled Energy Photometry
This will be used for fitting observed data to a brightness distribution, and to find the absolute flux from an extended region. We need to know the absolute value of the height of the PRF, which is normalized by the pinhole EE measurements.
Encircled energy is defined as flux contained in a circle defined by a mechanical aperture or a region defined in data analysis on an imaging detector.
= angle about the Z axis;
= "tilt"angle, an angle about an axis in the horizontal plane that rotates when
rotates, and is coincident with the Y axis when
= 0.
= roll angle, which will not be varied, but should be set up to be the same as in flight with respect to the SI.
Encircled energy for each aperture, off-axis angle, temperature and energy.
Accuracy: 1%, so we can derive the on-orbit encircled energy to 2%, up to the diameter that encloses 99% of the energy. At larger diameters, we don't care, because the error will be less than 1%.
Sunyaev-Zeldovich, and other experiments where the absolute flux is important. The angular sizes of these objects could be from
1
arcsec to arc minutes.
= 0 arcmin,
= 0 arcmin,
= 0° 15 Pinholesb : 0.1, 0.16, 0.22, 0.34, 0.6, 0.76, 0.96, 1.1, 1.4, 1.7, 2.8, 13, 40, 200, 800 arcsec.
2.1.1
EE(20, 100:2,20:13,1,20,1)
= {[(15 x (6 x 20 + 342) + (100 x 2+ 20 x 13)) x 1+0] x 20 + 900 x 19}x 1 + 0 = 45.8 hr
10 Pinholes: 0.1, 0.16, 0.22, 0.34, 0.6, 0.76, 0.96, 1.7, 2.8, 13 arcsec
={[(10
x
(6
x
20+ 342)
+(
100
x
2
+
20
x
8))
x
1+0] x4+900x3}x3+86400x2 = 66.8 hr
Deep survey; cluster and supernova remnant surface brightness mapping
11 energies: Be K, C K, Cr L, Cu L, Al K, Ag L, Ti K
, Cr K, Fe K, CuK, Ge K
={[(5 x (6 x 20+ 342) +( 20 x 5)) x 10+600 x 9] x11+900x10}x1+0 = 92.6 hr
={[(5 x (6 x 20+ 342) +( 20 x 5)) x 36+600 x 35] x4+900x3}x1+0= 120.5 hr
2.2 Inner Point Response Function Imaging
2D mapping of the details of the inner part of the image, including
azimuthal structure.
Accuracy: 1% of the measured value out to 3 arcsec, 2%from 3 to 20 arcsec, .
At 100 c s-1 pixel-1 in the HSI, the XGA can give enough flux to achieve that rate out to 10-2 of the peak intensity of the image, 3 arcsec. Therefore, we can run at maximum counting rates to that angle. 2 x 104 counts (100 c s-1 pixel-1) in inner, 5000 in outer. Total time alotted is 1400 sec per exposure, to be broken down later into a series of shorter exposures at different source intensities.
Details of structure of strong near-point sources; detection of faint
sources and extended structure near strong point sources (limit:
0.01 Crab).
0.12 arcsec cells within 2 arcsec
25 energies (see Table 15 ).
2.2.1
hsiimage(1400,200,1,1,3) +hsiimage(1400,0,1,25,3)
= {[(5.5+1400+ 1.6 x 200)]} x 3+{[(5.5+1400)] x 25+900 x (24-1)} x 3 = 48.6 hr
High Speed Imager
(HRC or ACIS would be much slower, since this experiment is count rate limited.), BND(FPCs, SSS), FMS
2.2.2
hsiimage(1400, 0, 5, 11, 3)
= {[(5.5+1400)x5 +600 x 4] x 11+900 x 10} x 3, sec = 93.9 hr
2.2.4
hsiimage(1400, 0, 15, 4,3)
={[(5.5+400)
x
15+600
x
14]
x
4+900
x
3}
x
3 = 50.5 hr
2.3 Outer Point Response Function Imaging
2D mapping of the qualitative features of the outer part of the image.
Accuracy: 15%of the measured point response from 20 to 60 arcsec. => 44 cnts/pixel, needs 67 sec/exposure.
For interstellar dust scattering, we need to distinguish between dust on the mirror and dust between us and the source.
Details of structure of strong, extended sources. Limit:
0.01 Crab).
8 arc sec cells from 16-60 arcsec; 30 arc sec cells from 1-6 arcmin;12 azimuth locations
25 energies (see Table 15 ).
2.3.2
hsiimage(67, 0, 5, 11, 3) =
2.3.4
hsiimage(67, 0, 25, 4, 3) =
2.4 Wing Scans
Record wings of PRF at angles > 6 arcmin off-axis, to edge of detector(HRC).
Accuracy: 1% of the measured value, or 10-5 of peak intensity, whichever is greater.
This may be a null experiment, if the wing flux is low enough
Why do we need this? I presume to be able to confront models of scattering from dust on the mirror, and interstellar scattering
3 arcmin cells from 6-17 arcmin; at large angles, use an annulus 5' x 17' = 4.5e-5 sr
10 energies (see Table 15 ).
2.4.1
hsiimage(350,200,1,1,1) + hsiimage(350,0,1,10,1)
= {[(5.5 +350)]}+{[(5.5 +350)] x 10+900 x 9}= 3.3 hr, done during sHRMA/HRC calibration, so not counted here.
2.5 X-ray ghost images, inner
Imaging detector used for quick survey, 0.006 mm resolution, out to 1.8 mm diameter.
Needed to avoid aliasing of images near strong sources outside the field of view.
2.5.1
hsiimage(500,200,24,2,1)
= {[(5.5+500+1.6x200) x 24+ 600 x (24-1)]x2+900x(2-1)} = 18.9 hr
2.6 Fluorescence
Spectroscopic measurements of fluorescence from sources outside the field of view.
Needed to avoid contamination of spectra from fluorescence of elements of AXAF by strong sources outside the field of view.
2.6.1
1.6 x 200 + hsiimage(3600, 0, 9, 1, 1) = 1.6 x 200+{[(5.5 +3600) x 9+600 x 8]}