Exposure Time Calculator - Spectroscopic mode

This exposure calculator predicts the signal-to-noise ratio achieved with LIRIS for a given exposure time and observing conditions. By default the sky brightness and  the  detector integration time are changed with filter.
To run the program enter values below and click on 'Submit'. You may set signal-to-noise and obtain the corresponding exposure time, or viceversa.

Input flux distribution
Source Magnitude mag [mag/arcsec²] Source Type
Continuum Type Temp./Power law index K/[n.u.]
Line flux erg/s/cm2 Line Center AA

Sky conditions
Seeing arcsec Airmass
Season Summer Time Winter Time

Instrument Setup
Grism & Slit width
arcsec Nod points Sky frames
Exposure Time ncycles Detector Integration Time sec Nruns
  Signal To Noise (around lambda)

Graphical Output
  S/N vs lambda
  Total signal/time vs lambda
  Source signal/time vs lambda
  Sky signal/time vs lambda


Please send queries and comments to: liris at ll.iac.es

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