STIS Instrument Handbook for Cycle 24

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6.6	Tabular Sky Backgrounds

We provide a table of the “high” sky background numbers as plotted in Figure 6.1, for easy reference. See the text and the caption in Figure 6.1 for more details. The high sky values are defined as the earthshine at 38° from the limb and by the high zodiacal light of mV = 22.1 arcsec-2. The contributions of the geocoronal emission lines are tabulated separately in Table 6.5.

Table 6.4: High Sky Background (excluding geocoronal emission lines)

Wavelength å	High Earthshine erg/s/cm2/ å/arcsec2	High Zodiacal Light erg/s/cm2/ å/arcsec2	Total Background erg/s/cm2/ å/arcsec2
1000	2.41e-23	9.69e-29	2.41e-23
1100	4.38e-22	1.04e-26	4.38e-22
1200	4.01e-23	1.08e-25	4.03e-23
1300	7.41e-25	6.59e-25	1.40e-24
1400	4.29e-25	2.55e-24	2.98e-24
1500	4.16e-25	9.73e-24	1.01e-23
1600	2.55e-25	2.35e-22	2.35e-22
1700	7.89e-25	7.21e-21	7.21e-21
1800	9.33e-23	1.53e-20	1.54e-20
1900	4.39e-22	2.25e-20	2.29e-20
2000	1.01e-21	3.58e-20	3.68e-20
2100	1.60e-21	1.23e-19	1.25e-19
2200	7.49e-22	2.21e-19	2.22e-19
2300	3.32e-22	1.81e-19	1.81e-19
2400	2.50e-22	1.83e-19	1.83e-19
2500	2.39e-22	2.53e-19	2.53e-19
2600	5.62e-22	3.06e-19	3.06e-19
2700	6.77e-21	1.01e-18	1.02e-18
2800	2.03e-21	2.88e-19	2.90e-19
2900	4.32e-20	2.08e-18	2.12e-18
3000	9.34e-20	1.25e-18	1.35e-18
3100	2.07e-19	1.50e-18	1.70e-18
3200	3.60e-19	2.30e-18	2.66e-18
3300	4.27e-19	2.95e-18	3.38e-18
3400	6.40e-19	2.86e-18	3.50e-18
3500	8.20e-19	2.79e-18	3.61e-18
3600	1.06e-18	2.74e-18	3.80e-18
3700	1.22e-18	3.32e-18	4.54e-18
3800	1.23e-18	3.12e-18	4.35e-18
3900	1.52e-18	3.34e-18	4.86e-18
4000	2.38e-18	4.64e-18	7.01e-18
4250	2.38e-18	4.65e-18	7.03e-18
4500	2.86e-18	5.58e-18	8.44e-18
4750	2.79e-18	5.46e-18	8.25e-18
5000	2.63e-18	5.15e-18	7.77e-18
5250	2.67e-18	5.37e-18	8.04e-18
5500	2.58e-18	5.34e-18	7.92e-18
5750	2.54e-18	5.40e-18	7.94e-18
6000	2.42e-18	5.25e-18	7.67e-18
6250	2.26e-18	5.02e-18	7.28e-18
6500	2.17e-18	4.92e-18	7.09e-18
6750	2.07e-18	4.79e-18	6.87e-18
7000	1.93e-18	4.55e-18	6.48e-18
7250	1.85e-18	4.43e-18	6.29e-18
7500	1.74e-18	4.23e-18	5.97e-18
7750	1.63e-18	4.04e-18	5.67e-18
8000	1.56e-18	3.92e-18	5.49e-18
8250	1.48e-18	3.76e-18	5.23e-18
8500	1.35e-18	3.50e-18	4.85e-18
8750	1.31e-18	3.43e-18	4.74e-18
9000	1.22e-18	3.23e-18	4.44e-18
9250	1.15e-18	3.07e-18	4.21e-18
9500	1.10e-18	2.98e-18	4.08e-18
9750	1.04e-18	2.86e-18	3.91e-18
10,000	1.00e-18	2.78e-18	3.78e-18
10,250	9.54e-19	2.67e-18	3.63e-18
10,500	9.04e-19	2.56e-18	3.46e-18
10,750	8.41e-19	2.41e-18	3.25e-18
11,000	8.03e-19	2.31e-18	3.11e-18

Table 6.5: Geocoronal (Airglow) Emission Lines

Wavelength (å)	ID	Line Width (å)	Intensity
			High		Average		Low
			kilo- Rayleighs	erg/s/cm2/ arcsec2	kilo- Rayleighs	erg/s/cm2/ arcsec2	kilo- Rayleighs	erg s/cm2/ arcsec2
1216	Lyα	0.04	~20	6.1e-13	~10	3.05e-13	2	6.1e-14
13021	O I	0.013	~2	5.7e-14	~1	2.85e-14	0.013	3.8e-16
1356	O I]	0.013	~0.2	5e-15	~0.1	2.50e-15	~ 0.001	3e-17
2471	[O II]	0.023	< 0.2	3e-15	<0.1	1.50e-15	< 0.001	1.5e-17

1

Blend of 1302.2, 1304.9, and 1306.0 with intensity ratio 3:2:1.