Stephen L. Redman, Gabriel G. Ycas, Ryan Terrien, Suvrath Mahadevan, Lawrence W. Ramsey, Chad F. Bender, Steven N. Osterman, Scott A. Diddams, Franklyn Quinlan, James E. Lawler, Gillian Nave
We present a high-resolution (R ~ 50 000) atlas of a uranium-neon (U/Ne)
hollow-cathode spectrum in the H-band (1454 nm to 1638 nm) for the calibration
of near-infrared spectrographs. We obtained this U/Ne spectrum simultaneously
with a laser-frequency comb spectrum, which we used to provide a first-order
calibration to the U/Ne spectrum. We then calibrated the U/Ne spectrum using
the recently-published uranium line list of Redman et al. (2011), which is
derived from high-resolution Fourier transform spectrometer measurements. These
two independent calibrations allowed us to easily identify emission lines in
the hollow cathode lamp that do not correspond to known (classified) lines of
either uranium or neon, and to compare the achievable precision of each source.
Our frequency comb precision was limited by modal noise and detector effects,
while the U/Ne precision was limited primarily by the signal-to-noise ratio
(S/N) of the observed emission lines and our ability to model blended lines.
The standard deviation in the dispersion solution residuals from the
S/N-limited U/Ne hollow cathode lamp were 50% larger than the standard
deviation of the dispersion solution residuals from the modal-noise-limited
laser frequency comb. We advocate the use of U/Ne lamps for precision
calibration of near-infrared spectrographs, and this H-band atlas makes these
lamps significantly easier to use for wavelength calibration.
View original:
http://arxiv.org/abs/1112.1062
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