Abstract
We present a method to optimize absorption cells for precise wavelength calibration in the nearinfrared. We apply it to design and optimize methane isotopologue cells for precision radial velocity measurements in the K band. We also describe the construction and installation of two such cells for the CSHELL spectrograph at NASA's IRTF. We have obtained their high-resolution laboratory spectra, which we can then use in precision radial velocity measurements and which can also have other applications. In terms of obtainable RV precision, methane should outperform other proposed cells, such as the ammonia cell ( 14NH 3) recently demonstrated on CRIRES/VLT. The laboratory spectra of the ammonia and methane cells show strong absorption features in the H band that could also be exploited for precision Doppler measurements. We present spectra and preliminary radial velocity measurements obtained during our first-light run. These initial results show that a precision down to 20-30 m s -1 can be obtained using a wavelength interval of only 5 nm in the K band and S=N ~ 150. This supports the prediction that a precision down to a few meters per second can be achieved on late-M dwarfs using the new generation of NIR spectrographs, thus enabling the detection of terrestrial planets in their habitable zones. Doppler measurements in the NIR can also be used to mitigate the radial velocity jitter due to stellar activity, enabling more efficient surveys on young active stars.
| Original language | English |
|---|---|
| Pages (from-to) | 586-597 |
| Number of pages | 12 |
| Journal | Publications of the Astronomical Society of the Pacific |
| Volume | 124 |
| Issue number | 916 |
| DOIs | |
| Publication status | Published - Jun 2012 |
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ASJC Scopus subject areas
- Astronomy and Astrophysics
- Space and Planetary Science
Cite this
Design and construction of absorption cells for precision radial velocities in the K band using methane isotopologues. / Anglada-Escudé, Guillem; Plavchan, Peter; Mills, Sean; Gao, Peter; García-Berríos, Edgardo; Lewis, Nathan S; Sung, Keeyoon; Ciardi, David; Beichman, Chas; Brinkworth, Carolyn; Johnson, John; Davison, Cassy; White, Russel; Prato, Lisa.
In: Publications of the Astronomical Society of the Pacific, Vol. 124, No. 916, 06.2012, p. 586-597.Research output: Contribution to journal › Article
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TY - JOUR
T1 - Design and construction of absorption cells for precision radial velocities in the K band using methane isotopologues
AU - Anglada-Escudé, Guillem
AU - Plavchan, Peter
AU - Mills, Sean
AU - Gao, Peter
AU - García-Berríos, Edgardo
AU - Lewis, Nathan S
AU - Sung, Keeyoon
AU - Ciardi, David
AU - Beichman, Chas
AU - Brinkworth, Carolyn
AU - Johnson, John
AU - Davison, Cassy
AU - White, Russel
AU - Prato, Lisa
PY - 2012/6
Y1 - 2012/6
N2 - We present a method to optimize absorption cells for precise wavelength calibration in the nearinfrared. We apply it to design and optimize methane isotopologue cells for precision radial velocity measurements in the K band. We also describe the construction and installation of two such cells for the CSHELL spectrograph at NASA's IRTF. We have obtained their high-resolution laboratory spectra, which we can then use in precision radial velocity measurements and which can also have other applications. In terms of obtainable RV precision, methane should outperform other proposed cells, such as the ammonia cell ( 14NH 3) recently demonstrated on CRIRES/VLT. The laboratory spectra of the ammonia and methane cells show strong absorption features in the H band that could also be exploited for precision Doppler measurements. We present spectra and preliminary radial velocity measurements obtained during our first-light run. These initial results show that a precision down to 20-30 m s -1 can be obtained using a wavelength interval of only 5 nm in the K band and S=N ~ 150. This supports the prediction that a precision down to a few meters per second can be achieved on late-M dwarfs using the new generation of NIR spectrographs, thus enabling the detection of terrestrial planets in their habitable zones. Doppler measurements in the NIR can also be used to mitigate the radial velocity jitter due to stellar activity, enabling more efficient surveys on young active stars.
AB - We present a method to optimize absorption cells for precise wavelength calibration in the nearinfrared. We apply it to design and optimize methane isotopologue cells for precision radial velocity measurements in the K band. We also describe the construction and installation of two such cells for the CSHELL spectrograph at NASA's IRTF. We have obtained their high-resolution laboratory spectra, which we can then use in precision radial velocity measurements and which can also have other applications. In terms of obtainable RV precision, methane should outperform other proposed cells, such as the ammonia cell ( 14NH 3) recently demonstrated on CRIRES/VLT. The laboratory spectra of the ammonia and methane cells show strong absorption features in the H band that could also be exploited for precision Doppler measurements. We present spectra and preliminary radial velocity measurements obtained during our first-light run. These initial results show that a precision down to 20-30 m s -1 can be obtained using a wavelength interval of only 5 nm in the K band and S=N ~ 150. This supports the prediction that a precision down to a few meters per second can be achieved on late-M dwarfs using the new generation of NIR spectrographs, thus enabling the detection of terrestrial planets in their habitable zones. Doppler measurements in the NIR can also be used to mitigate the radial velocity jitter due to stellar activity, enabling more efficient surveys on young active stars.
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U2 - 10.1086/666489
DO - 10.1086/666489
M3 - Article
VL - 124
SP - 586
EP - 597
JO - Publications of the Astronomical Society of the Pacific
JF - Publications of the Astronomical Society of the Pacific
SN - 0004-6280
IS - 916
ER -