ETC Request ID: STIS.sp.1330694

Exposure time (seconds) = 1,000.0000 at wavelength 1550.00 Å

gives: SNR = 40.7380 (per resolution element)

Exposure time calculation HAD WARNINGS.

WARNING MESSAGE: Buffer time 22.5911 is less than minimum 99 seconds.

WARNING MESSAGE: MAMA Bright limits: total count rate per image 88530.3 exceeds limit for irregularly-variable sources 40 percent of the bright limit 200000 counts per second


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 0.920 1,840.51 42.90
    Background 0.001 2.10 1.45
        Sky 3.260e-13 6.52e-10 2.55e-05
        Dark Current 0.001 2.10 1.45
Total in selected region 0.921 1,842.61 45.18
Brightest Pixel (single exposure) (at 1332.91 Å) 0.803 802.95
Count rate entire detector 88,530.251
Buffer Time (sec) 22.59
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 53,236.624 53,236,624.446
    Background (sky+dark) 157.418 157,418.16
Encircled energy fraction 0.95

Instrument name: STIS
Mode: spectroscopic
Detector: FUVMAMA
Central Wavelength: 1425
Grating: [E140M] R ~ 45800
Aperture: 0.2X0.2
Glow region: low


Target: [point source]
Spectrum: Flat in units of Fλ
Extinction E(B-V): None
Normalization: Flux 1.5e-11 flam at 1550.0 Å
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 27.1