Source Count Rates

Table 5.5 shows measured HRI count rates for a sample of sources and compares these rates to that of the PSPC and the Einstein Observatory HRI and IPC.

Object ROSAT Einstein ROSAT Einstein

HRI HRI PSPC IPC

HZ 43 12.0 3.6 100 3.8

v AR Lac 0.65 0.69 7.4 1.3

v Cyg X-2 72 27.8 180 NA

v LMC X-1 3.8 1.3 10 10.55

v LMC X-3 2.6 2.7 NA NA

Cas A 17 6.3 57 61

Tycho 10.2 3.4 NA 22.3

Kepler 5.4 1.7 NA 7.3

E 0102.2-72.2 (SMC SNR) 0.96 0.25 NA 0.79

N132D 3.6 1.1 10.6 4.0

a A 2256 0.62 NA 1.7 0.34

v: variable source

a: the count rate for A 2256 is determined from the net emission within a 6' radius

Table 5.5: Comparison of X-ray count rates (counts/s) between the HRI/PSPC detectors of ROSAT and the HRI/IPC detectors of Einstein

	Object	ROSAT	Einstein	ROSAT	Einstein
		HRI	HRI	PSPC	IPC
	HZ 43	12.0	3.6	100	3.8
v	AR Lac	0.65	0.69	7.4	1.3
v	Cyg X-2	72	27.8	180	NA
v	LMC X-1	3.8	1.3	10	10.55
v	LMC X-3	2.6	2.7	NA	NA
	Cas A	17	6.3	57	61
	Tycho	10.2	3.4	NA	22.3
	Kepler	5.4	1.7	NA	7.3
	E 0102.2-72.2 (SMC SNR)	0.96	0.25	NA	0.79
	N132D	3.6	1.1	10.6	4.0
a	A 2256	0.62	NA	1.7	0.34
v: variable source
a: the count rate for A 2256 is determined from the net emission within a 6' radius