ETC Request ID: STIS.sp.640598
Exposure time (seconds) = 750.0000 at wavelength 2796.00 Å
gives: SNR = 161.3466 (per resolution element)
Exposure time calculation HAD WARNINGS.
WARNING MESSAGE: MAMA Bright limits: total count rate per image 184704 exceeds limit for irregularly-variable sources 40 percent of the bright limit 200000 counts per second
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 | 17.837 | 26,755.40 | 163.57 |
| Background | 0.013 | 18.90 | 4.35 |
| Sky | 1.072e-09 | 1.61e-06 | 1.27e-03 |
| Dark Current | 0.013 | 18.90 | 4.35 |
| Total in selected region | 17.850 | 26,774.30 | 165.83 |
| Brightest Pixel (single exposure) (at 2796.20 Å) | 25.086 | 18,814.84 | |
| Count rate entire detector | 184,703.670 | ||
| Buffer Time (sec) | |||
| 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 | 156,386.856 | 117,290,142.298 | |
| Background (sky+dark) | 1,887.437 | 1,415,577.64 | |
| Encircled energy fraction | 0.93 | ||
| Instrument name: | STIS |
| Mode: | spectroscopic |
| Detector: | NUVMAMA |
| Central Wavelength: | 2713 |
| Grating: | [E230H] R ~ 114000 |
| Aperture: | 0.2X0.09 |
| Target: [point source] | |
| Spectrum: | User uploaded spectrum: ALPCEN-B-UV.dat |
| Extinction E(B-V): | None |
| Normalization: | None |
| 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 22.2
