Results

The absolute flux at the ACIS filter in photons per second per centimeter squared is shown in Table  4.34. The statistical error of the flux rates presented is generally 0.1 percent, with a worse case of 0.5 percent.
 
 

Table 4.34: Estimated High Speed Tap Flux at ACIS Focal Plane Corrected for Pileup, Filter Efficiency, and CCD Efficiency in photons per second per centimeter squared in the line.

 

Science Runs	Energy	i0	i1	i2	i3	s0	s1	s2	s3	s4	s5
70 71	525	18.1	18.3	18.2	17.3	18.6	26.2	18.9	24.6	18.1	18.0
88 89	705	23.7	23.3	23.5	23.8	23.6	40.0	24.4	39.9	25.7	23.8
111 112	1487	171.7	171.7	172.2	172.4	171.7	172.7	172.5	174.5	173.1	172.4
72 75	1740	39.5	39.6	39.8	39.7	39.6	41.4	39.5	41.7	39.6	39.3
107 108	2166	73.2	73.6	73.8	73.6	73.2	76.3	74.4	78.9	73.6	74.3
120 122 123	4509	64.7	66.0	65.0	65.9	76.8	68.6	74.0	75.1	70.8	69.3
77 78 83 84	6399	78.3	79.1	79.5	79.4	79.5	73.4	79.0	76.1	78.8	78.5
92 93	8040	242.9	244.4	240.4	245.7	254.1	230.9	246.4	233.2	243.4	247.8

The relative efficiencies of the ACIS flight devices compared to s2 are shown in Table  4.35.
 
 

Table 4.35: High Speed Tap Based Quantum Efficiencies Relative to the s2 Detector

 

Science Runs	Energy	i0	i1	i2	i3	s0	s1	s2	s3	s4	s5
70 71	525	0.755	0.805	0.825	0.887	0.922	3.311	1.000	3.216	0.843	0.807
88 89	705	0.559	0.867	0.684	0.652	0.851	3.193	1.000	3.173	0.914	0.854
111 112	1487	0.967	0.949	0.962	0.972	0.978	1.076	1.000	1.161	0.984	0.975
72 75	1740	0.965	0.967	0.976	0.971	0.948	0.672	1.000	1.042	0.956	0.943
107 108	2166	0.944	0.957	0.970	0.958	0.964	1.282	1.000	1.328	0.975	0.964
120 122 123	4509	1.002	1.007	0.995	0.999	0.998	0.843	1.000	0.969	1.003	0.994
77 78 83 84	6399	0.949	0.950	0.957	0.954	0.951	0.604	1.000	0.750	0.992	0.976
92 93	8040	0.901	0.906	0.891	0.911	0.936	0.489	1.000	0.638	0.990	0.976

The ratio of ACIS counts to SSD 5 counts is shown in Table  4.36. The SSD 5 count rates used are from "flux_d3" column of ftp://es81-server1.msfc.nasa.gov/xrayastronomy/QE_energy_total.rdb, which was last updated August 13, 1997.
 

Table 4.36: ACIS Count Rate Divided by SSD 5 Count Rate

 

Science Runs	Energy	i0	i1	i2	i3	s0	s1	s2	s3	s4	s5
70 71	525	3.621	3.862	3.960	4.256	4.422	15.887	4.798	15.430	4.044	3.870
88 89	705	0.790	1.224	0.966	0.921	1.201	4.508	1.412	4.479	1.290	1.205
111 112	1487	0.977	0.958	0.972	0.982	0.988	1.087	1.010	1.173	0.994	0.985
72 75	1740	1.156	1.158	1.169	1.163	1.135	0.805	1.198	1.249	1.145	1.129
107 108	2166	0.782	0.793	0.804	0.794	0.799	1.063	0.829	1.100	0.808	0.799
120 122 123	4509	0.785	0.789	0.780	0.783	0.782	0.661	0.784	0.760	0.787	0.780
77 78 83 84	6399	0.792	0.793	0.799	0.796	0.793	0.504	0.834	0.626	0.828	0.815
92 93	8040	0.617	0.620	0.610	0.624	0.641	0.335	0.685	0.437	0.678	0.668