Astronomical source definition

Spatial profile and brightness: (more info)
Choose one of point, extended or user-defined source profile and the brightness in any filter/wavelength
Point source (nominal PSF) with spatially integrated brightness (e.g. 19.3 mag or 2e-17 W/m²/µm)
Extended source having ...(When this option is selected the image quality selection in section 3 of the ITC is disabled.)
Gaussian profile with full width half maximum (including seeing) of arcsec and spatially integrated brightness of (e.g. 19.3 mag or 2e-17 W/m²/µm)
Uniform surface brightness (e.g. 21.6 mag/arcsec²)
with the above brightness normalisation applied in filter band

Spectral distribution: (more info)
Choose one SED, the redshift and extinction
Library spectrum of a non-stellar object
Single emission line at wavelength micron with line flux and line width km/s on a flat (in wavelength) continuum of flux density
Model black body spectrum with temperature K
Model power-law spectrum (S_lambda = lambda ^ )
User-defined spectrum read from file (size < 1MB)
with the spectrum mapped to a redshift z = or a radial velocity v = km/s


Instrument (Michelle) and telescope configuration

Instrument optical properties:
Filter: Focal plane unit:
Grating: Spectrum central wavelength: µm
Polarimetry: disabled enabled
Detector properties:
The following are the read noise and dark current values used by the ITC:
Read noise:   4,000 e- per pixel
Dark current:   270,000 e-/s per pixel
Telescope configuration: (more info)
Mirror coating: silver
Instrument port: up-looking (2 reflections) side-looking (3 reflections)
Wavefront sensor for tip-tilt compensation: PWFS (no OIWFS)


Observing condition constraints

Please read the explanatory notes for the meaning of the percentiles and to ensure that your selected conditions are appropriate for the observing wavelength. Further details are available on the observing condition constraints pages.
Image Quality: 20%/Best 70%/Good 85%/Poor Any
Cloud Cover: 50%/Clear 70%/Cirrus 80%/Cloudy Any
Water Vapor: 20%/Low 50%/Median 80%/High Any
Sky Background: 20%/Darkest 50%/Dark 80%/Grey Any/Bright (explanatory notes)
Airmass: <1.2 1.5 2.0


Details of observation

Calculation method: (more info)
Select the calculation method (note: second method is not available for spectroscopy)
Total S/N ratio resulting from a total time of secs and with a fraction of exposures that observe the source (number of individual exposures will be calculated from assumed frame time)
Total integration time to achieve a S/N ratio of and with a fraction of exposures that observe the source
Telescope offset:(more info)
Dither offset size: arcsec
Analysis method: (more info)
Software aperture that gives 'optimum' S/N ratio and with a sky aperture times the target aperture
Software aperture of diameter (or slit length) arcsec and with a sky aperture times the target aperture
For spectroscopy, autoscale or specify limits for plotted spectra (lower wavelength µm and upper wavelength µm)