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Retrievals of atmospheric composition from near-infrared measurements require measurements of airmass to better than the desired precision of the composition. The oxygen bands are obvious choices to quantify airmass since the mixing ratio of oxygen is fixed over the full range of atmospheric conditions. The OCO-2 mission is currently retrieving carbon dioxide concentration using the oxygen A-band for airmass normalization. The 0.25% accuracy desired for the carbon dioxide concentration has pushed the required state-of-the-art for oxygen spectroscopy. To measure O2 A-band cross-sections with such accuracy through the full range of atmospheric pressure requires a sophisticated line-shape model (Rautian or Speed-Dependent Voigt) with line mixing (LM) and collision induced absorption (CIA). Models of each of these phenomena exist, however, this work presents an integrated self-consistent model developed to ensure the best accuracy. It is also important to consider multiple sources of spectroscopic data for such a study in order to improve the dynamic range of the model and to minimize effects of instrumentation and associated systematic errors. The techniques of Fourier Transform Spectroscopy (FTS) and Cavity Ring-Down Spectroscopy (CRDS) allow complimentary information for such an analysis. We utilize multispectrum fitting software to generate a comprehensive new database with improved accuracy based on these datasets. The extensive information will be made available as a multi-dimensional cross-section (ABSCO) table and the parameterization will be offered for inclusion in the HITRANonline database.

We report here the most precise constraint to date on the spectrum of the cosmic background radiation (CBR), obtained from measurements made with a liquid-helium-cooled spectrometer carried above the atmosphere on a rocket. The spectrum is very well fitted by a Planck function of temperature 7=2.736 K. The scatter of the equivalent temperature in the band 3-16 cm -1 is ±10 mK, about j% of the mean whereas the estimated overall accuracy of the mean temperature is ± 17 mK. These results are inconsistent with a previously reported excess ir intensity in the CBR but are in good agreement with COBE results.PACS numbers: 98.70.Vc, 98.80.Es The cosmic background radiation (CBR), discovered in 1965, 1 is a very important observable for the field of cosmology, being one of the oldest entities accessible to measurement. In the simple big-bang scenario, 2 " 4 it is identified as highly redshifted radiation which was in equilibrium with matter just as the temperature of the Universe fell to a value permitting the formation of neutral hydrogen. In this standard model the spectrum of the CBR would be strictly Planckian (or thermal), this form remaining invariant under expansion of the Universe; early measurements were consistent with a temperature of about 2.7 K. 5 For values of the redshift parameter z less than about 10 7 , however, radiation-matter interactions are insufficient to completely thermalize the radiation spectrum in case it is perturbed. Thus, energy-releasing processes occurring since that time can be expected to have left their imprint on the CBR, and accurate measurements of deviations from a Planckian spectrum can give important information about such processes. 6 In the range 10 7^z^l 0 4 conditions would be such that kinetic equilibrium, but not thermodynamic equilibrium, is established between electrons and photons, resulting in a Bose-Einstein spectrum characterized by a chemical potential /z, a measure of the deposition of energy relative to the radiative energy density. For z;Sl0 4 , even kinetic equilibrium cannot be established, but Compton scattering occurs resulting in a typical spectrum characterized by a "Comptonization" parameter y, a measure of the discrepancy between electron and radiative temperatures. The results reported here set close constraints on both ju and y.There are several difficulties in making detailed checks on the thermal nature of the spectrum over a wide spectral range. First, since the Earth's atmosphere is opaque at wavelengths where the CBR is expected to be most intense (A,;S2 mm), measurements in this important spectral range need to be made from high altitude. Second, the low temperature of the source necessitates the use of cryogenic techniques to minimize contaminating radiation of the measuring instrument itself. And third, since the radiation is of such low intensity, one needs to avoid sources such as the Earth, the Sun, or dust in the plane of our galaxy.Based on experience gained with earlier attempts to measure the CBR spectrum from rockets, 7-9 a new instrum...

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Precise near-infrared radial velocimetry enables efficient detection and transit verification of low-mass extrasolar planets orbiting M dwarf hosts, which are faint for visible-wavelength radial velocity surveys. The TripleSpec Exoplanet Discovery Instrument, or TEDI, is the combination of a variable-delay Michelson interferometer and a medium-resolution (R=2700) near-infrared spectrograph on the Palomar 200" Hale Telescope. We used TEDI to monitor GJ 699, a nearby mid-M dwarf, over 11 nights spread across 3 months. Analysis of 106 independent observations reveals a root-mean-square precision of less than 37 m s −1 for 5 minutes of integration time. This performance is within a factor of 2 of our expected photon-limited precision. We further decompose the residuals into a 33 m s −1 white noise component, and a 15 m s −1 systematic noise component, which we identify as likely due to contamination by telluric absorption lines. With further development this technique holds promise for broad implementation on medium-resolution near-infrared spectrographs to search for low-mass exoplanets orbiting M dwarfs, and to verify low-mass transit candidates. (Chabrier 2003). Combining the M V luminosity function for single main-sequence field stars (Wielen et al. 1983) with the distance modulus, one can calculate the relative number of single main-sequence stars in a magnitude-limited wide-field transit survey. Comparing the number of single, main sequence stars with M V from 2.5 to 8.5, corresponding to F, G and K dwarfs, to the number with M V from 8.5 to 18.5, corresponding to M-type dwarfs, one finds that F, G and K dwarfs outnumber M dwarfs in magnitude-limited wide-field survey by more than 1000 to 1. To overcome this limitation, the MEarth transit survey is individually targeting bright M dwarfs, rather than staring at a single field (Nutzman & Charbonneau 2008) at the expense of continuous coverage. Despite the challenges, both visible-wavelength radial velocity surveys and transit surveys have had success with M dwarfs. As of now, 27 planets have been detected around 21 M dwarfs, and two are known to transit their host stars: GJ 1214 b and GJ 436 b. All hosts have a spectral type earlier than M5. GJ 1214 b was initially detected by the MEarth transit survey, then confirmed by radial velocity measurements (Charbonneau et al. 2009), and GJ 436 b was initially discovered by a radial velocity survey (Butler et al. 2004) with the transit detection occurring later (Gillon et al. 2007). At this stage it is unclear whether the majority of future M dwarf transiting planets will be detected first by transit surveys then followed up with radial velocity measurements, or vice-versa, given that both individually target M dwarfs. However, the Kepler Mission is a sensitive wide-field transit survey observing approximately 2500 M dwarfs brighter than V = 14. If low-mass planets are common around M dwarfs, Kepler will potentially detect dozens of transiting candidates around M dwarfs which are bright enough for follow up radial veloci...