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ENERGY-CHANNEL Conversion Table

(for FTOOLS 4.1, pca_e2c_e03v04.fits, and Epoch 4)

This table contains information about the channel-energy relationship for RXTE PCA data for the three gain epochs of the mission so far (Epoch 1 = launch through 3/21/96; Epoch 2 = 3/21/96 - 4/15/96; Epoch 3 = 4/15/96 - 3/22/99; Epoch 4 = 3/22/99 - present). In each case the data were generated for the full PCA with all detectors and layers added, using FTOOLS 4.1 and the energy-to-channel file pca_e2c_e03v04.fits (except epoch 4, which used a new, not-yet-released version.) If you have used earlier versions of the response matrix generation tools, you will notice small differences between your values and the values given here. (The energy-channel conversion for FTOOLS 3.7 is available for comparison.)

The PCA onboard electronics bin up the channels differently depending on which configuration has been requested. The first column contains the ORIGINAL (or absolute) channels, while the second column contains the channel binning for Standard 2 data (which is the type of data most RXTE analysts start on). Subsequent columns give the maximum energy bound for each channel.

IMPORTANT NOTES:

  • Remember that when you perform channel selection, the extractors require you to supply the ORIGINAL channel boundaries, regardless of the mode of data you are analyzing (Std2, Binned, Event, GoodXenon etc). For further details see the ABC guide, or the cookbook recipe "Creating and plotting light curves, hardness ratios and color-color diagrams."

  • The information in this table is useful for most cases, but should be considered only approximate (within a few percent). If you are performing analysis for which the exact values of the energy boundaries are critical, or if you are analyzing data from separate layers and detectors, you should generate a response matrix for your particular dataset and examine the channel-energy information contained in the first extension of the FITS file.

  • Note that the response matrix generator in FTOOLS 4.1 now accounts for the slow gain drift in the PCA. This gain shift amounts to ~ 1 % over two years. The Epoch 3 and 4 values given in the table below are computed for the beginning of each epoch.



EPOCH:                    1      2       3       4
START DATE:               -    3/21/96 4/15/96 3/22/99
STOP DATE:             3/21/96 4/15/96 3/22/99  -
(stop time:)           (18:33) (23:05) (17:37)  

        
          CHANNEL      E_MAX   E_MAX   E_MAX   E_MAX
       (Abs)  (Std2)    keV     keV     keV     keV
               
	0-4	0	1.28	1.55	1.83	2.18
	5	1	1.55	1.86	2.19	2.62
	6	2	1.81	2.17	2.54	3.06
	7	3	2.07	2.48	2.90	3.50
	8	4	2.34	2.79	3.27	3.94
	9	5	2.60	3.10	3.63	4.38
	10	6	2.86	3.40	3.99	4.82
	11	7	3.13	3.71	4.35	5.26
	12	8	3.39	4.02	4.71	5.70
	13	9	3.66	4.33	5.07	6.14
	14	10	3.92	4.64	5.43	6.58
	15	11	4.19	4.95	5.79	7.02
	16	12	4.45	5.26	6.16	7.46
	17	13	4.71	5.57	6.52	7.90
	18	14	4.98	5.88	6.88	8.34
	19	15	5.24	6.19	7.24	8.78
	20	16	5.51	6.50	7.61	9.22
	21	17	5.78	6.81	7.97	9.66
	22	18	6.00	7.12	8.34	10.1
	23	19	6.31	7.45	8.70	10.5
	24	20	6.57	7.75	9.06	10.9
	25	21	6.84	8.06	9.43	11.4
	26	22	7.10	8.37	9.79	11.8
	27	23	7.37	8.68	10.16	12.3
	28	24	7.64	9.00	10.52	12.7
	29	25	7.90	9.31	10.89	13.2
	30	26	8.17	9.62	11.25	13.6
	31	27	8.44	9.93	11.62	14.0
	32	28	8.71	10.25	11.99	14.5
	33	29	8.97	10.56	12.35	14.9
	34	30	9.24	10.87	12.72	15.4
	35	31	9.51	11.19	13.09	15.8
	36	32	9.78	11.50	13.45	16.3
	37	33	10.04	11.81	13.82	16.7
	38	34	10.31	12.13	14.19	17.2
	39	35	10.58	12.44	14.56	17.6
	40	36	10.85	12.76	14.92	18.0
	41	37	11.12	13.07	15.29	18.5
	42	38	11.39	13.39	15.66	18.9
	43	39	11.66	13.70	16.03	19.4
	44	40	11.92	14.02	16.40	19.8
	45	41	12.19	14.33	16.77	20.3
	46	42	12.46	14.65	17.14	20.7
	47	43	12.73	14.97	17.51	21.2
	48	44	13.00	15.28	17.88	21.6
	49	45	13.27	15.60	18.25	22.1
	50	46	13.54	15.92	18.62	22.5
	51	47	13.81	16.23	18.99	23.0
	52	48	14.08	16.55	19.36	23.4
	53	49	14.35	16.87	19.73	23.9
	54-5	50	14.90	17.50	20.48	24.8
	56-7	51	15.44	18.14	21.22	25.7
	58-9	52	15.98	18.77	21.97	26.6
	60-1	53	16.53	19.41	22.71	27.5
	62-3	54	17.07	20.05	23.46	28.4
	64-5	55	17.62	20.69	24.21	29.3
	66-7	56	18.16	21.33	24.96	30.2
	68-9	57	18.71	21.97	25.71	31.1
	70-1	58	19.26	22.61	26.47	32.0
	72-3	59	19.80	23.26	27.22	32.9
	74-5	60	20.35	23.90	27.97	33.8
	76-7	61	20.90	24.55	28.73	34.7
	78-9	62	21.45	25.19	29.49	35.6
	80-1	63	22.00	25.84	30.24	36.5
	82-3	64	22.55	26.48	31.00	37.4
	84-5	65	23.11	27.13	31.76	38.3
	86-7	66	23.66	27.78	32.52	39.2
	88-9	67	24.21	28.43	33.29	40.1
	90-1	68	24.77	29.08	34.05	41.1
	92-3	69	25.32	29.73	34.81	42.0
	94-5	70	25.88	30.39	35.58	42.9
	96-7	71	26.43	31.04	36.34	43.8
	98-9	72	26.99	31.69	37.11	44.7
	100-1	73	27.55	32.35	37.88	45.6
	102-3	74	28.11	33.00	38.65	46.6
	104-5	75	28.67	33.66	39.42	47.5
	106-7	76	29.23	34.32	40.20	48.4
	108-9	77	29.79	34.98	40.97	49.3
	110-1	78	30.35	35.64	41.74	50.2
	112-3	79	30.91	36.30	42.52	51.2
	114-5	80	31.48	36.96	43.30	52.1
	116-7	81	32.04	37.62	44.08	53.0
	118-9	82	32.60	38.29	44.86	54.0
	120-1	83	33.17	38.95	45.64	54.9
	122-3	84	33.74	39.62	46.42	55.8
	124-5	85	34.30	40.28	47.20	56.7
	126-7	86	34.87	40.95	47.99	57.7
	128-9	87	35.44	41.62	48.77	58.6
	130-1	88	36.01	42.29	49.56	59.5
	132-3	89	36.58	42.96	50.35	60.5
	134-5	90	37.15	43.63	51.14	61.4
	136-8	91	38.01	44.64	52.32	62.8
	139-41	92	38.87	45.65	53.51	64.2
	142-4	93	39.73	46.66	54.70	65.6
	145-7	94	40.59	47.68	55.90	67.0
	148-50	95	41.46	48.70	57.10	68.4
	151-3	96	42.32	49.72	58.30	69.9
	154-6	97	43.19	50.74	59.50	71.3
	157-9	98	44.06	51.76	60.71	72.7
	160-2	99	44.94	52.79	61.92	74.1
	163-5	100	45.81	53.82	63.13	75.5
	166-8	101	46.69	54.85	64.34	77.0
	169-71	102	47.57	55.88	65.56	78.4
	172-4	103	48.45	56.92	66.78	79.8
	175-7	104	49.33	57.96	68.01	81.3
	178-80	105	50.21	59.00	69.24	82.7
	181-3	106	51.10	60.04	70.47	84.1
	184-6	107	51.99	61.09	71.70	85.6
	187-9	108	52.88	62.14	72.94	87.0
	190-2	109	53.77	63.19	74.18	88.5
	193-5	110	54.66	64.24	75.42	89.9
	196-8	111	55.56	65.30	76.67	91.4
	199-201	112	56.46	66.36	77.92	92.8
	202-4	113	57.36	67.42	79.18	94.3
	205-7	114	58.26	68.48	80.43	95.7
	208-10	115	59.16	69.55	81.69	97.2
	211-3	116	60.07	70.62	82.96	98.7
	214-6	117	60.98	71.69	84.22	100.
	217-9	118	61.89	72.76	85.49	101.
	220-2	119	62.80	73.84	86.77	103.
	223-5	120	63.71	74.92	88.05	104.
	226-8	121	64.63	76.00	89.33	106.
	229-31	122	65.55	77.09	90.61	107.
	232-4	123	66.47	78.18	91.90	109.
	235-7	124	67.40	79.27	93.19	110.
	238-41	125	68.63	80.73	94.92	112.
	242-5	126	69.87	82.19	96.66	114.
	246-9	127	71.11	83.66	98.40	116.
	250-5	128	72.98	85.87	101.02	119.