ETC Request ID: STIS.sp.1029594

Exposure time (seconds) = 1,000.0000 at wavelength 9000.00 Å

gives: SNR = 13.3225 (per resolution element)

gives: Time to Saturation (for a single exposure) = 34,780.73 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 (9.7) 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 0.292 584.58 24.18
    Background 0.132 264.50 16.26
        Sky 0.006 12.50 3.53
        Dark Current 0.126 252.00 15.87
    Read Out 32.81
Total in selected region 0.425 849.08 43.88
Brightest Pixel (single exposure) (at 5819.10 Å) 0.949 474.40
Global Count Rates
    Source only 988.108 988,108.433
    Background (sky+dark) 20,299.709 20,299,709.13
Encircled energy fraction 0.74

Instrument name: STIS
Mode: spectroscopic
Detector: CCD
Central Wavelength:
Grating: [G750L] R ~ 500
Aperture: 52X2
Gain: 1.0
# Frames: 2
Binning: dispersion: 1, spatial: 1
Dark: medium


Target: [point source]
Spectrum: User uploaded spectrum: wd2341+322.etc
Extinction E(B-V): None
Normalization: Renormalized to abmag = 17.47 in filter Sloan/I
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 25.2