- PIO
- Sciops
- Gemini Home
- Telescopes and Sites
- Science Visitors at Gemini
- Observing With Gemini
- Instruments
- NORTH
- ALTAIR
- GMOS
- GNIRS
- NIFS
- NIRI
- SOUTH
- FLAMINGOS-2
- GeMS
- GMOS
- GPI
- GSAOI
- NICI
- VISITING
- Visiting Instrument Policy
- DSSI Speckle Camera (North)
- TEXES (North)
- RESOURCES
- Integration Time Calculators
- Adaptive Optics
- GCAL
- Magnitudes and Fluxes
- Near-IR Resources
- Mid-IR Resources
- Observing Condition Constraints
- Performance Monitoring
- SV/Demo Science

- Future Instrumentation
- Queue and Schedules
- Data and Results
- Helpdesk
- Statistics

Change page style:

# Spectroscopic throughput

**Spectroscopic Throughput**

All throughput measurements are based on observations of spectrophotometric standards, collected under photometric conditions. Throughputs are defined as follows:

T(λ) = |
N
_{d}(λ) N_{t} (λ) |

where: * N _{d}(λ) * is the number of photons detected with wavelength λ and

*N*is the number of photons of the same wavelength hitting the telescope's primary mirror. The latter is given by:

_{t}(λ) N _{t}(λ) = N_{*}(λ) 10 ^{(-0.4 μ Aλ) } |

where *N _{*}(λ)* is the star's photon flux at wavelength λ above Earth's atmosphere, in number of photons/cm

^{2}/s,

*μ*is the airmass, and

*A*is a mean monochromatic extinction coefficient.

_{λ}
*The numbers available below are average values,
that do not account for throughput variations as a function of grating
angle. *

Instrument | Gratings | Latest Throughput | All measurements |

NIFS | ZJHK | 20140306 | ZJHK |