MUSE Exposure Time Calculator

Optical AO Integral-Field Spectroscopy Mode Version 6.0.1
Description
FAQ
 
The page is loading... please wait!

Target Flux Distribution

Target Spatial Distribution:

Infinitely Extended Source
Extended Uniform Source Finite diameter: arcsec (max 30)
Sersic profile
Radius inside which half of the luminosity is :
If below 0".1 , a point source is assumed
arcsec (max 15)
Strength of decrease (0.5 to 10, 4=deVaucouleurs) :
Point Source
 
Distance from target object center at which the S/N or exp.time must be computed: arcsec
Irrelevant for Infinitely Extended Source. For other profiles, distance must be below source radius + 7".5

Target Spectral Distribution and Brightness:

Uniform (constant with wavelength) Target Magnitude and Mag.System:   
= Vega
AB

Magnitudes are given per arcsec2 for extended
sources, and as the integral photometry for
point sources and Sersic profiles.

Magnitudes refer to the redshifted spectrum.
Blackbody: Temperature : K
Template Spectrum: Redshift
z =
Upload Spectrum:
Supported formats: FITS images and two-column ASCII,
with wavelength in nm units and ascending order,
and a flux unit proportional to erg/cm2/s/A.
The spectrum will be scaled to the given magnitude.
Single Line :
Lambda: nm
Flux: 10-16 erg/s/cm2  (per arcsec2 for extended sources)
FWHM: nm    (minimum 0.25 nm)

Background Source Flux Distribution

expand section...

Background Source Spatial Distribution:

None
Infinitely Extended Source
Extended Uniform Source Finite diameter: arcsec (max 30)
Sersic profile
Radius inside which half of the luminosity is :
If below 0".1, a point source is assumed
arcsec (max 15)
Strength of decrease (0.5 to 10, 4=deVaucouleurs) :
Point Source
 
Distance from background object center at which the S/N or exp.time must be computed: arcsec
Irrelevant for Infinitely Extended Source. For other profiles, distance must be below source radius + 7".5

Background Source Spectral Distribution and Brightness:

Uniform (constant with wavelength) Background Source Magnitude and Mag. System:
= Vega
AB

Magnitudes are given per arcsec2 for extended
sources, and as the integral photometry for
point sources and Sersic profiles.

Magnitudes refer to the redshifted spectrum.
Blackbody: Temperature : K
Template Spectrum: Redshift
z =
Upload Spectrum:
Supported formats: FITS images and two-column ASCII,
with wavelength in nm units and ascending order,
and a flux unit proportional to erg/cm2/s/A.
The spectrum will be scaled to the given magnitude.
Single Line :
Lambda: nm
Flux:   10-16 erg/s/cm2 (per arcsec2 for extended sources)
FWHM: nm   (minimum 0.25 nm)

Instrument Setup

Instrument Mode:
Number of coadded spatial pixels:
Number of coadded spectral pixels:

Sky Conditions

Moon phase: days from new Moon
Airmass:
Seeing/Image Quality:
The resulting Image Quality FWHM is approximated by a gaussian in the ETC considering the transfer functions of the atmosphere, telescope and instrument. See the helpfile for details.
Seeing: arcsec FWHM in V-band at zenith (use this value in the proposal)
              Probability ---% of realising the seeing ≤ 0.80 arcsec
IQ: arcsec FWHM at the airmass and wavelength of observation (to be used for the OB constraint set)
              This is the IQ FWHM at the reference wavelength defined in the Observational Setup section below.
The corresponding seeing and probability will be indicated in the ETC output page
Image Quality is not a parameter in AO modes


Observation Setup

Reference Wavelength: λref= nm. The numeric results will refer to this wavelength.
Wavelength range to plot: λmin= nm         λmax= nm

User provides S/N ratio and NDIT --- ETC returns DIT
User provides S/N ratio and DIT --- ETC returns NDIT
User provides NDIT and DIT --- ETC returns S/N ratio
S/N = NDIT = DIT = s

The total exposure time is the product of DIT (Detector Integration Time) by NDIT (number of DITs). This exposure time does not take into account instrument and telescope overheads.


On submission the model can generate the following:

Plots: Toggle All / No Plots

Peak Pixel values
Target Spectrum, per Spectral Bin Target Spectrum, per Spectral Pixel
Sky Emission per Pixel
Sky Transmission
S/N per Spectral Bin S/N per Pixel
System Efficiency (excl.atmosphere)
Target Input Spectrum in Physical Units
Target Ensquared Energy
Background Object per Spectral Bin Background Object per Spectral Pixel
Background Object Input Spectrum in Physical Units
Background Object Ensquared Energy

FITS files: Toggle All / No FITS files

PSF at the requested image quality and the reference wavelength
Target Object
Target Image: the Target convolved by the PSF
Background Object
Background Object Image: the Background Object convolved by the PSF