MOSFIRE *UNVERIFIED* Exposure Time Calculator
Template: JAB: z:
Seeing [as]: Slit [as]: Npix:
Npairs: texp [s]: ttotal:

The following table summarizes the expected spectral resolution R (λ/Δλ), and S/N ratio in the best quartiles (25%, 50%, 75%, and 100%). To get a sense for the number of total detected photons an example wavelength is selected in each band near the median signal-to-noise ratio. Note that the values are summed over exposures assuming Poisson statistics. The total number of photons from the object and sky are computed in a resolution element at the example wavelength. Note that A/B subtraction is assumed and accounted for in the s/n calculation.
Typ. Slit-Limited R:
S/N Quartiles:
Detector noise per resolution element includes a read-noise of and dark-current shot-noise of .
Note that Total RN=RNpixel · (Npix · Npairs · 2)1/2

The slit and extraction diameter subtend . Extraction losses for the slit width and seeing amount to .


Detected Signal to Noise Ratio per Resolution Element

Detected Photons per resolution element in a single exposure. Bottom horizontal lines indicate total read noise and dark current (in photons). Top horizontal lines indicate where the detector becomes one-percent non linear or saturated.

Emitted AB Magnitude SED of object and Sky for the given slit and seeing.
The SEDs

Throughput (Sky, Slit, Optics, and Detector)
MOSFIRE's Throughput as a function of wavelength