ETC Request ID: STIS.sp.1177436

Exposure time (seconds) = 250.0000 at wavelength 1400.00 Å

gives: SNR = 117.0410 (per resolution element)

Exposure time calculation HAD WARNINGS.

WARNING MESSAGE: MAMA Bright limits: total count rate per image 21737.1 exceeds limit for irregularly-variable sources 40 percent of the bright limit 30000 counts per second

WARNING MESSAGE: Buffer time 92.0085 is less than minimum 99 seconds.


Table of Source and Noise Counts per Pixel

Plots

Detailed Information Count rate Total counts Associated noise
(counts/s) (counts) (counts)
Counts (box 7 pixels high) (1 pix x 7 pix) (2 pix resel x 7 pix)
    Source 27.398 13,699.13 117.04
    Background 0.001 0.53 0.72
        Sky 2.445e-12 1.22e-09 3.50e-05
        Dark Current 0.001 0.53 0.72
Total in selected region 27.399 13,699.65 117.05
Brightest Pixel (single exposure) (at 1244.10 Å) 21.974 5,493.52
Count rate entire detector 21,737.116
Buffer Time (sec) 92.01
For APT purposes, the recommended buffer time should be 4/5 of the buffer time calculated above. Please refer to the STIS Instrument Handbook for more details.
Global Count Rates
    Source only 21,466.815 5,366,703.843
    Background (sky+dark) 270.300 67,575.04
Encircled energy fraction 0.82

Instrument name: STIS
Mode: spectroscopic
Detector: FUVMAMA
Central Wavelength:
Grating: [G140L] R ~ 1000
Aperture: 52X0.2
Glow region: low


Target: [point source]
Spectrum: User uploaded spectrum: calibrated_uv_w3.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 26.1