ETC Request ID: STIS.sp.1036577

Requested Signal/Noise Ratio = 50.000 at wavelength 7000.00 Å (per resolution element)

gives: Time = 91.9906 seconds

gives: Time to Saturation (for a single exposure) = 2,897.56 seconds

Exposure time calculation HAD WARNINGS.

WARNING MESSAGE: Partial overlap between instrument throughput band and target spectrum. Please doublecheck the wavelength range covered by the selected spectrum, and the instrument documentation for the selected filter.

WARNING MESSAGE: "Electrons per pixel due to background (0.83) 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

Plots

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 20.467 3,765.54 61.36
    Background 0.127 23.46 4.84
        Sky 0.001 0.27 0.52
        Dark Current 0.126 23.18 4.81
    Read Out 43.39
Total in selected region 20.594 3,788.99 75.31
Brightest Pixel (single exposure) (at 6799.10 Å) 41.414 1,904.86
Global Count Rates
    Source only 14,071.318 1,294,428.384
    Background (sky+dark) 19,017.198 1,749,402.65
Encircled energy fraction 0.90

Instrument name: STIS
Mode: spectroscopic
Detector: CCD
Central Wavelength:
Grating: [G750L] R ~ 500
Aperture: 52X0.2
Gain: 4.0
# Frames: 2
Binning: dispersion: 1, spatial: 1
Dark: medium


Target: [point source]
Spectrum: Non-stellar Objects QSO (SDSS based) [800, 8554.5 Å z=0]
Extinction E(B-V): Milky Way Diffuse (Rv=3.1) = 0.015 applied before normalization
Normalization: Flux 6e-15 flam at 4392.0 Å
Redshift: z=0.0353
Emission Lines: None


Selected background:
  Sky Background:
    Level:

Table of Source and Noise Counts per Pixel

Plots

These results were computed using: ETC version 25.2