Spectroscopy
Throughput Curves
The following plot shows the measured throughputs for all the Echelle
spectral orders
available. The throughputs are
based on on-sky measurements of the Feige 110 standard acquired in
December 2020 (courtesy of Joe Hennawi). The spectra were not corrected for slit loss. They
include the contribution of the telescope and the atmospheric
effects. The sharp cut off blueward from 1 micron is due to the
coating of the prisms.
Reduced Spectra (sky subtracted, flatfielded, extracted)
Combined Orders |
Echelle |
Photometric |
central |
Mag. for |
Order |
band |
λ |
SNR=5 in 1 hour |
5 and 6 |
J |
1.25μm |
J=21.2 |
4 |
H |
1.635μm |
H=21.7 |
3 |
K |
2.20μm |
K=21.8 |
Notes:
- Based on observations of HIP 61425 (J=10.306, H=10.339, and K= 10.437).
- Magnitudes are in the Vega system.
- Magnitude equivalent to reach SNR=5 within the spectral range
defined by the filter quoted in 1 hour per resolution element in an extracted spectrum.
- The magnitude calculation assumes that the noise is
dominated by source or sky background.