TRISPEC Sensitivity (UKIRT f/36)

These are preliminary results estimated from the UKIRT observartion at August 2000. The following sensitivities is based on the mesured throughput, readnoise, dark current of  TRISPEC, the sky brightness, and the predicted photon noise. Please note that because of  the poor weather condition and the some uncertainty of  the detecter gain, the some uncertainty can be still remained in the following sensitivities.

Imaging mode:

Surface Brightness

1 sigma magnitudes;  per pixel
Filter Exposure Time (seconds)
  1 10 60 100 600 3600
V 22.4 24.7 26.0 26.4 27.4 28.4
J 20.9 23.1 24.4 24.6 25.7 26.7
Ks 19.7 21.8 23.1 23.4 24.4 25.4

Point source

10 sigma magnitudes;
seeing: 0.9" (V), 0.7" (J, Ks); aperture: 2" (V), 1.8" (J, Ks)
Filter Exposure Time (seconds)
  1 10 60 100 600 3600
V 16.5 18.8 20.2 20.6 21.6 22.6
J 16.0 19.6 19.5 19.8 20.8 21.8
Ks 14.8 17.0 18.3 18.6 19.6 20.6

 

Imaging polarimetry mode:

Surface Brightness

283 sigma (polarization accuracy of 0.5%) magnitudes;  per pixel
Filter Exposure Time (seconds)
  1 10 60 100 600 3600
V 16.3 18.6 19.9 20.3 21.3 22.3
J 14.8 17.0 18.3 18.5 19.6 20.6
Ks 13.6 15.7 17.0 17.3 18.3 19.3

Point Source

 283 sigma (polarization accuracy of 0.5%) magnitudes;
seeing: 0.9" (V), 0.7" (J, Ks); aperture: 2" (V), 1.8" (J, Ks)
Filter Exposure Time (seconds)
  1 10 60 100 600 3600
V 12.9 15.2 16.6 17.0 18.0 19.0
J 12.4 16.0 15.9 16.2 17.2 18.2
Ks 11.2 13.4 14.7 15.0 16.0 17.0

 

Spectroscopy mode with the low dispersion grisms:

Point Source

10 sigma magnitudes;
0.88" slit; seeing: 0.8" (0.55, 1.25µm), 0.7" (2.15µm);  aperture: 2.1"(0.55µm), 2"(1.25, 2,15µm)
wavelength (µm) Exposure Time (seconds)
  1 10 60 100 600 3600
0.55 12.7 15.2 17.0 17.5 18.9 20.0
1.25 12.3 14.7 16.5 17.0 18.2 19.3
2.15 10.0 12.5 14.2 14.6 15.8 16.9

 

Spectro-polarimetry mode with the low dispersion grisms:

Point Source

 283 sigma (polarization accuracy of 0.5%) magnitudes;
0.88 slit; seeing: 0.8" (0.55, 1.25µm), 0.7" (2.15µm);  aperture: 2.1"(0.55µm), 2"(1.25, 2,15µm)
wavelength (µm) Exposure Time (seconds)
  1 10 60 100 600 3600
0.55 9.1 11.6 13.4 13.9 15.3 16.4
1.25 8.7 11.1 12.9 13.4 14.6 15.7
2.15 6.4 8.9 10.6 11.0 12.2 13.3

Notes


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Last Modification Date: 2000/09/26
Last Modification Author: Makoto Watanabe <watanabe@z.phys.nagoya-u.ac.jp>