Space Telescope Science Institute
COS Instrument Handbook
help@stsci.edu
Table of Contents Previous Next Index Print


Cosmic Origins SpectrographInstrument Handbookfor Cycle 22 > Chapter 1: An Introduction to COS > 1.3 COS Quick Reference Guide

1.3
Table 1.1: COS Instrument Characteristics
(G130M along-dispersion1)
1
Raw plate scale.

Table 1.2: COS Detector Characteristics
Cs2Te (semi-transparent)
MgF2 (re-entrant)
85 10 mm (two)
25.6 25.6 mm
16,384 1024 (two)
1024 1024
16,384 128 (two, ACCUM)
16,384 1024 (two, TIME-TAG)
1024 1024
6 24 μm
25 25 μm
6 10 pix
3 3 pix
Typical dark-count rate (away from SAA)1
2.77 / 1.39 cnt s–1 cm–2
4 10–6 / 2 10–6 cnt s–1 pix–1
2.56 10–4 / 1.28 10–4 cnt s–1 resel–1
170 cnt s–1 cm–2
1.06 10–3 cnt s–1 pix–1
9.54 10–3 cnt s–1 resel–1
Detector global count rate limit2
30,000 cnt s–1 (but counts lost at rates above ~21,000 cnt s–1)
~15,000 cnt s–1 per segment
~1.67 cnt s–1 pix–1
~40 cnt s–1 resel–1
~50 cnt s–1 pix–1
~180 cnt s–1 resel–1
7.4 μs
1
The dark-count rate values are projections to the middle of Cycle 22 (April 2015).
2
Count rates higher than these limits will trigger a detector shut-down. Bright-object screening limits are lower. See Chapter 10.
3
The FUV values are not applicable to the COS FUV G130M blue cenwaves, 1055 and 1096. The local count rate limit for these two modes is 0.2 cnt s1 pix1.

Table 1.3: COS Calibration Accuracies
Flat field quality (spectral S/N) per resel, using standard techniques
100:11
1
See Section 5.8.1.

Table 1.4: Useful Figures and Tables
HST focal plane and COS aperture

Cosmic Origins SpectrographInstrument Handbookfor Cycle 22 > Chapter 1: An Introduction to COS > 1.3 COS Quick Reference Guide

Table of Contents Previous Next Index Print