John Henry Lacy

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latitudes 308–358S. This variation is not correlated with the 200-mbar temperature. It can be explained by a decrease of High spectral resolution measurements of NH3 and PH3 lines the eddy mixing coefficient near 240 mbar from p4000 to #400 on Jupiter in the 10.5to 11.2-mm range are presented. Observacm sec between the two latitude ranges. The PH3 mixing(More)
We discuss the design and performance of TEXES, the Texas Echelon Cross Echelle Spectrograph. TEXES is a mid-infrared (5-25 µm) spectrograph with several operating modes: high-resolution, cross-dispersed with a resolving power of R = λ/δλ ≈ 100,000, 0.5% spectral coverage, and a ∼ 1.5 × 8 ′′ slit; medium-resolution long-slit, with R ≈ 15,000, 0.5% coverage,(More)
where static stability is maximum. The NH3 lineshape 12 days following impact indicates a gradual depletion of the Spatially resolved spectroscopy of the Shoemaker–Levy 9 high altitude source, which suggests that NH3 was partially (SL9) sites traces the dynamical evolution of cometary mateshielded from UV radiation. Enhanced continuum emission rial,(More)
We present infrared spectra of four embedded protostars in the 750-1230 cm-1 (13.3-8.1 microns) range. For NGC 7538 IRS 9, a new band is reported at 1110 cm-1 (9.01 microns, and several others may be present near 785, 820, 900, 1030, and 1075 cm-1 (12.7, 12.2, 11.1, 9.71, and 9.30 microns). The band 1110 cm-1 is attributed to frozen NH3. Its position and(More)
We evaluated the optical performance of an IR echelle grating produced on a silicon wafer with anisotropic etching techniques. We measured the diffraction efficiency of a sample with a 55° blaze angle and 25-µm groove spacing. We also calculated the efficiency for typical triangular and trapezoidal groove profiles of etched gratings. The diffraction(More)
We investigate theoretically the use of an electron in a Penning trap as a detector of single microwave photons. At the University of Sussex we are developing a chip Penning trap technology, designed to be integrated within quantum circuits. Microwave photons are guided into the trap and interact with the electron’s quantum cyclotronmotion. This is an(More)
In this talk I presented and discussed our unexpected detection of water vapor in the disk-averaged spectrum of the K2IIIp red giant Arcturus [for details, see Ryde et al. (2002)]. Arcturus, or α Boötes is, with its effective temperature of 4300 K, the hottest star yet to show water vapor features. We argue that the water vapor is photospheric and that its(More)
We present high spectral resolution mid-IR observations of SiS towards the C-rich AGB star IRC+10216 carried out with the Texas Echelon-cross-Echelle Spectrograph mounted on the NASA Infrared Telescope Facility. We have identified 204 ro-vibrational lines of 28Si32S, 26 of 29Si32S, 20 of 28Si34S, and 15 of 30Si32S in the frequency range 720 - 790 cm-1.(More)
We are developing a high spectral resolution grating spectrograph as a PI instrument for the Stratospheric Observatory for Infrared Astronomy (SOFIA). The Echelon-Cross-Echelle Spectrograph (EXES) will operate at 5.5-28.5 m in three spectroscopic modes: R 10, 2 10, and 4000. We use an echelon, a coarsely ruled, steeply blazed di raction grating to achieve(More)
We report detections of pure rotation lines of OH and H2O in the K1.5 III red-giant star Arcturus (α Boötis) using high-resolution, infrared spectra covering the regions 806−822 cm (12.2−12.4μm) and 884−923 cm (10.8−11.3μm). Arcturus is the hottest star yet to show water-vapor features in its disk-averaged spectrum. We argue that the water vapor lines(More)