ETC Request ID: STIS.sp.1369096

Exposure time (seconds) = 600.0000 at wavelength 1700.00 Å

gives: SNR = 26.9091 (per resolution element)

Exposure time calculation HAD WARNINGS.

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

WARNING MESSAGE: Buffer time 22.5911 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 0.663 795.12 28.20
    Background 0.001 1.26 1.12
        Sky 1.166e-11 1.40e-08 1.18e-04
        Dark Current 0.001 1.26 1.12
Total in selected region 0.664 796.38 29.55
Brightest Pixel (single exposure) (at 1332.91 Å) 0.803 481.77
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 31,941,974.667
    Background (sky+dark) 157.418 94,450.90

Encircled energy fraction 0.94


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 1700.0 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 27.2