ETC Request ID: STIS.sp.1035904
Requested Signal/Noise Ratio = 500.000 at wavelength 9500.00 Å (per resolution element)
gives: Time = 171.7575 seconds
gives: Time to Saturation (for a single exposure) = 286.43 seconds
Exposure time calculation HAD WARNINGS.
WARNING MESSAGE: "Electrons per pixel due to background (1.5) is less than the recommended threshold of 20 electrons to avoid poor charge transfer efficiency (CTE). We suggest you consider CTE mitigation strategies described in the STIS Instrument Handbook."
Table of Source and Noise Counts per Pixel
| Detailed Information | Count rate | Total counts | Associated noise |
| (e-/s) | (e-) | (e-) | |
| Counts (box 7 pixels high) | (1 pix x 7 pix) | (2 pix resel x 7 pix) | |
| Source | 733.335 | 251,911.41 | 501.91 |
| Background | 0.126 | 43.30 | 6.58 |
| Sky | 4.701e-05 | 0.02 | 0.13 |
| Dark Current | 0.126 | 43.28 | 6.58 |
| Read Out | 43.39 | ||
| Total in selected region | 733.461 | 251,954.70 | 503.82 |
| Brightest Pixel (single exposure) (at 9050.55 Å) | 418.944 | 35,978.40 | |
|
|
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| Global Count Rates | |||
| Source only | 1,225,516.112 | 210,491,582.214 | |
| Background (sky+dark) | 18,882.328 | 3,243,181.51 | |
| Encircled energy fraction | 0.68 | ||
| Instrument name: | STIS |
| Mode: | spectroscopic |
| Detector: | CCD |
| Central Wavelength: | 9336 |
| Grating: | [G750M] R ~ 5000 |
| Aperture: | 52X0.1 |
| Gain: | 4.0 |
| # Frames: | 2 |
| Binning: | dispersion: 1, spatial: 1 |
| Dark: | medium |
| Target: [point source] | |
| Spectrum: | Bruzual Synthetic Stellar Spectra O7 V |
| Extinction E(B-V): | Milky Way Diffuse (Rv=3.1) = 1.96 applied before normalization |
| Normalization: | Renormalized to vegamag = 5.2 in filter Johnson/J |
| 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 25.2
