ETC Request ID: STIS.sp.1371620

Exposure time (seconds) = 7,200.0000 at wavelength 2500.00 Å

gives: SNR = 8.1867 (per resolution element)

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 0.011 155.73 12.48
    Background 0.014 201.60 14.20
        Sky 7.002e-09 1.01e-04 0.01
        Dark Current 0.014 201.60 14.20
Total in selected region 0.025 357.33 19.02
Brightest Pixel (single exposure) (at 2681.81 Å) 0.011 76.34
Count rate entire detector 2,303.916
Buffer Time (sec) 868.09
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 168.098 1,210,302.396
    Background (sky+dark) 2,097.156 15,099,519.89
Encircled energy fraction 0.93

Instrument name: STIS
Mode: spectroscopic
Detector: NUVMAMA
Central Wavelength: 2707
Grating: [E230M] R ~ 30000
Aperture: 0.2X0.2


Target: [point source]
Spectrum: User uploaded spectrum: WD1145+017_UV-cols.txt
Extinction E(B-V): None
Normalization: Flux 5e-15 flam at 1340.0 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