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FEROS Exposure Time Calculator

Optical Echelle Spectroscopy Mode Version 6.0.0
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Input Flux Distribution

Blackbody T: Kelvin
Power Law Index: F(λ) is proportional to λ(Index)
Template Spectra Redshift z: The redshift is only applicable with the option Template Spectra.
Object Magnitude (Vega system):   Band: Vega AB The object magnitude is only relevant for the three options above.
Note that some template spectra are defined over a limited wavelength range and may not allow calculations for all instrument configurations. The object magnitude is not taken into account for single line sources.
Single line λ: [350-900] nm FWHM: nm Flux 10-16 ergs/s/cm2
Spatial Distribution: Point Source

Sky Conditions

Moon phase: days from new Moon
Seeing: arcsec FWHM in V-band at zenith (use this value in the proposal). The seeing is irrelevant for extended sources.
Probability 60% for a seeing smaller or equal to the requested value
For point sources, the resulting Image Quality FWHM is modeled by the ETC considering the transfer functions of the atmosphere and telescope. See the helpfile for details.

Instrument Setup

ADC enable ADC
Note: In the current model, the ADC transmission curve is included when ADC is enabled, but the only airmass dependency is the reduction of object flux due to the atmospheric extinction. The airmass dependency of the fiber aperture loss due to the differential atmospheric diffraction (which the ADC is correcting for) is currently not considered.
CCD mode:

In the binning,the second value refers to the direction of the dispersion in the spectra

Exposure Time:


Tables:  Toggle All / No Tables
Spectral Format
Expected Counts
Graphs:  Toggle All / No Graphs
Input Spectrum
Maximum Intensity
Details of Image Quality Calculations (only for pointsources)

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