ETC Request ID: STIS.sp.1370717

Requested Signal/Noise Ratio = 5.000 at wavelength 1215.61 Å (per resolution element)

gives: Time = 2,044.7576 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.


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 0.007 30.21 5.50
    Background 0.002 6.29 2.51
        Sky 4.882e-04 2.00 1.41
        Dark Current 0.001 4.29 2.07
Total in selected region 0.009 36.50 6.04
Brightest Pixel (single exposure) (at 1215.95 Å) 0.031 64.15
Count rate entire detector 171.719

Buffer Time (sec) 11,646.97
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 1.535 3,139.633
    Background (sky+dark) 170.183 347,983.16

Encircled energy fraction 0.76


Instrument name: STIS
Mode: spectroscopic
Detector: FUVMAMA
Central Wavelength: 1222
Grating: [G140M] R ~ 10000
Aperture: 52X0.05
Glow region: low


Target: [point source]
Spectrum: User uploaded spectrum: spec_136.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 27.2