ETC Request ID: ACS.sp.905752

Requested Signal/Noise Ratio = 10.000 at wavelength 6500.00 Å (per resolution element)

gives: Time = 0.2508 seconds

gives: Time to Saturation (for a single exposure) = 228.81 seconds

Exposure time calculation HAD WARNINGS.

WARNING MESSAGE: Result of the calculation 0.0626971 seconds is less than the minimum exposure time for this detector (0.5 seconds)

WARNING MESSAGE: Electrons per pixel due to background (0.01) is less than the recommended threshold of 20 electrons to avoid poor charge transfer efficiency (CTE). In rare cases, post-flash may be recommended. Please see http://www.stsci.edu/hst/acs/performance/cte/cte_postflash.html.


Table of Source and Noise Counts per Pixel

Plots

Detailed Information Count rate Total counts Associated noise
(e-/s) (e-) (e-)
Counts (box 5 pixels high) (1 pix x pix) (2 pix resel x pix)
    Source 638.732 320.37 17.90
    Background 0.830 0.42 0.65
        Sky 0.799 0.40 0.63
        Dark Current 0.031 0.02 0.12
    Read Out 26.56
Total in selected region 639.562 320.79 32.04
Brightest Pixel (single exposure) (at 7400.00 Å) 370.173 23.21
Global Count Rates
    Source only 73,233.217 18,366.029
    Background (sky+dark) 2,784,913.051 698,423.41
Encircled energy fraction 0.88

Instrument name: ACS
Mode: spectroscopic
Detector: WFC
Grism: [G800L] Grism(R~100)
Gain: 2.0
# Frames: 4


Target: [point source]
Spectrum: Flat in units of Fλ
Extinction E(B-V): None
Normalization: Renormalized to vegamag = 15.0 in filter Johnson/V
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 25.1.1