Mauna Kea site properties
The Mauna Kea OH Line Emission Spectrum
The following spectra show the OH line emission spectrum in the J, H, K
windows at UKIRT. The spectra were taken with CGS4 using the 150 l/mm
grating at 3rd order in J, and 2nd order at H & K and the 256 x 256
InSb array (0.61" x 0.61" pixels).
At the bottom of the page are links to more
detailed spectra of individual regions of each band. Use these to check
the details of the OH emission lines in your wavelength region of interest.
The spectra were wavelength calibrated using this table of OH
Click on any of the three spectra below to see a larger scale plot of the
Please be aware that each spectrum is not shown to the same scale. The
OH lines in the H window are much stronger than in K, and those in K are
stronger than those in the J band.
The flux units are given as counts, 1 count = 6 electrons, and are per
pixel per 100 seconds.
The spectra are not corrected for atmospheric transmission.
Wavelengths are in vacuo.
The solid angle for a 0.61" x 0.61" pixel is 8.7455x10-12
The data were obtained by Tom Geballe and Tom Kerr on UT date 1997 19 December
The CSO taumeter
read approximately 0.05 while the data were obtained. This corresponds
to an H2O column of 1mm, a good night on
Individual wavelength regions
The spectra below show individual spectral segments covered by the 150
l/mm grating at the listed wavelengths. Approximate airmass is given in
brackets. In the J band 3rd order was used (wavelength coverage 0.055um),
2nd order was used for H & K (0.08um).
See the details in the UKIRT astronomy calibration area,
See the information in the UKIRT astronomy calibration area,