ETC Request ID: STIS.sp.1364943

Requested Signal/Noise Ratio = 10.000 at wavelength 2500.00 Å (per resolution element)

gives: Time = 3.4277 seconds

gives: Time to Saturation (for a single exposure) = 236.55 seconds

Exposure time calculation HAD WARNINGS.

WARNING MESSAGE: "Electrons per pixel due to background (0.045) 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 54.967 376.82 19.41
    Background 0.182 1.25 1.12
        Sky 2.394e-07 1.64e-06 1.28e-03
        Dark Current 0.182 1.25 1.12
    Read Out 32.28
Total in selected region 55.149 378.07 37.68
Brightest Pixel (single exposure) (at 3050.80 Å) 139.503 239.09
Global Count Rates
    Source only 86,228.445 295,567.474
    Background (sky+dark) 27,263.847 93,452.99
Encircled energy fraction 0.95

Instrument name: STIS
Mode: spectroscopic
Detector: CCD
Central Wavelength:
Grating: [G230LB] R ~ 700
Aperture: 52X0.05
Gain: 1.0
# Frames: 2
Binning: dispersion: 1, spatial: 1
Dark: medium


Target: [point source]
Spectrum: User uploaded spectrum: qcomb_spec.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

Plots

These results were computed using: ETC version 27.2