ETC Request ID: STIS.sp.847905
Exposure time (seconds) = 537.0000 at wavelength 1425.00 Å
gives: SNR = 55.1514 (per resolution element)
Exposure time calculation HAD WARNINGS.
WARNING MESSAGE: MAMA Bright limits: total count rate per image 128586 exceeds limit for irregularly-variable sources 40 percent of the bright limit 200000 counts per second
WARNING MESSAGE: Buffer time 15.5538 is less than minimum 99 seconds.
Table of Source and Noise Counts per Pixel
| Detailed Information | Count rate | Total counts | Associated noise |
| (counts/s) | (counts) | (counts) | |
| Counts (box 7 pixels high) | (1 pix x pix) | (2.0 pix resel x pix) | |
| Source | 3.289 | 3,532.34 | 59.43 |
| Background | 0.001 | 1.13 | 1.06 |
| Sky | 6.523e-15 | 7.01e-12 | 2.65e-06 |
| Dark Current | 0.001 | 1.13 | 1.06 |
| Total in selected region | 3.290 | 3,533.47 | 64.05 |
| Brightest Pixel (single exposure) (at 1344.93 Å) | 1.273 | 683.38 | |
| Count rate entire detector | 128,585.857 | ||
| Buffer Time (sec) | 15.55 | ||
| For APT purposes, the recommended buffer time should be 4/5 of the buffer time calculated above. Please refer to the STIS Instrument Handbook for more details. | |||
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| Global Count Rates | |||
| Source only | 77,366.528 | 41,545,825.688 | |
| Background (sky+dark) | 157.327 | 84,484.37 | |
| Encircled energy fraction | 0.94 | ||
| Instrument name: | STIS |
| Mode: | spectroscopic |
| Detector: | FUVMAMA |
| Central Wavelength: | 1425 |
| Grating: | [E140M] R ~ 45800 |
| Aperture: | 0.2X0.06 |
| Glow region: | low |
| Target: [point source] | |
| Spectrum: | Castelli-Kurucz Models O3V 45000 4.5 |
| Extinction E(B-V): | Milky Way CCM (Rv=4.0) = 0.514 applied before normalization |
| Normalization: | Flux 3.4e-11 flam at 1500.0 Å |
| Redshift: | None |
| Emission Lines: | None |
| Selected background: | |
| Sky Background: | |
| Level: |
Table of Source and Noise Counts per Pixel
These results were computed using: ETC version 24.2
