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
Library spectrum of a star (300 nm - 6 µm)
Single emission line at wavelength µm 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 (GMOS South) and telescope configuration

Instrument optical properties: (more info)
Grating: Spectrum central wavelength: nm
Filter: Focal plane unit:
Detector properties: (more info)
CCD type: Hamamatsu array EEV legacy array
Detector binning:
  • Spatial: 1 (no binning) 2 pixels 4 pixels
         (For imaging this applies to both the x- and y-directions. For spectroscopy this corresponds to the y-direction.)
  • Spectral: 1 (no binning) 2 pixels 4 pixels
         (This corresponds to the x-direction for spectroscopy. It is unused for imaging.)
  • Region of Interest:
    Amp gain:    Amp read mode:
    Telescope configuration: (more info)
    Mirror coating: silver
    Instrument port: side-looking (3 reflections)
    Wavefront sensor for tip-tilt compensation: PWFS 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 arcsec
    Cloud Cover: 50%/Clear 70%/Cirrus 80%/Cloudy Any mag
    Water Vapor: 20%/Low 50%/Median 80%/High Any
    Sky Background: 20%/Darkest 50%/Dark 80%/Grey Any/Bright
    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 exposures each having an exposure time of secs and with a fraction of exposures that observe the source
    Imaging integration time to achieve a S/N ratio of using an exposure time for each exposure of secs and with a fraction of exposures that observe the source
    Imaging integration time to achieve a S/N ratio of
    Spectroscopy integration time to achieve a S/N ratio of measured at nm.
    Telescope offset:(more info)
    Dither offset size: arcsec
    Analysis method (non IFU): (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
    Analysis Method for Integral Field Unit (IFU) spectroscopy:
    Note: A single IFU element is a 0.2 arcsec diameter hexagon (more info)
    Number of IFU fibres for sky: (250 for IFU red/blue, 500 for IFU-2, 1 for IFU nod & shuffle)
    Select an individual IFU element offset by arcsec from the center
    Select multiple IFU elements along a radius with offsets of to arcsec
    Sum all IFU elements within arcsec of the center
    For spectroscopy, autoscale or specify limits for plotted spectra (lower wavelength µm and upper wavelength µm)