Exoplanet atmospheres

Abstract:

3D is a new type of a highly sensitive near-infrared integral field spectrometer developed at MPE. It has been designed to multiplex spectral as well as spatial information thus obtaining a full data cube in a single integration. At a spectral resolution between 1000 and 2000 and a field of view of 16 x 16 pixels, optimized for subarcsecond spatial resolution imaging spectroscopy, it has a much higher efficiency compared to conventional techniques. Outfitting one of the VLTs with a near-IR 3D type instrument will provide a powerful tool for diffraction-limited integral field spectroscopic research, in particular on faint high-z galaxies in the early universe. The basic design, recent upgrades as well as plans for a possible VLT-3D instrument are presented.

Abstract:

We report 1'' K-band imaging spectroscopy of the z=2.284 galaxy IRAS F10214+4724. We find that the rest-frame H alpha and [N II] emission have different spatial extents. Furthermore, we detect broad (Delta upsilon(FWZP)approximate to 3500 km s(-1)) H alpha emission. We conclude that F10214+4724 is a very luminous gravitationally lensed galaxy, which intrinsically contains both a type 1 AGN and a more extended star-forming disk. The AGN and circumnuclear star formation both contribute significantly to the total luminosity of similar to 10(13)L(circle dot).

Abstract:

Scientific results from NIMS observations of Venus have been extensively reported in the literature, while those of Jupiter have, at the time of writing, just barely commenced. The planning and interpretation of studies of these planets, with their massive atmospheres and exotic compositions (by terrestrial standards), requires a comprehensive treatment of radiative transfer in both. This paper describes work done at Oxford to develop the underlying theory and practical radiative transfer schemes, with particular reference to the NIMS wavelength range, spectral resolution, and scientific objectives for Jupiter. Equivalent work for Venus has already been reported in the literature (e.g. Kamp and Taylor, 1990) and will not be covered in detail here. (C) 1997 COSPAR. Published by Elsevier Science Ltd.

Abstract:

We present new near-infrared integral field spectroscopy and adaptive optics imaging of the nucleus of NGC 1068. Using the stellar CO absorption features in the H and K bands, we have identified a moderately extincted stellar core centered on the nuclear position and of intrinsic size similar to 50 pc. We show that this nuclear stellar core is probably 5-16 x 10(8) years in age and contributes at least 7% of the total nuclear luminosity of similar to 1 x 10(11) L..

Abstract:

The spectrum of Saturn from 43 to 197 μm was measured with the ISO Long Wavelength Spectrometer (LWS) during the performance verification phase of the mission. The measurements were made using the LWS in grating mode, with spectral resolutions of 0.29 μm from 43 to 90 μm and 0.6 μm from 90 to 197 μm. The spectrum was compared with an atmospheric radiative-transfer model and four results were obtained: first, the slope of the measured continuum within each detector passband is in good agreement with the model; second, absorption features due to ammonia and phosphine were unambiguously detected, and all detected features were attributed to these two molecules; third, the ammonia absorption features agree reasonably well with the nominal model (based on Voyager IRIS measurements); and fourth, the phosphine absorption features disagree with the nominal model. Superior agreement with the measured spectrum was obtained with a modified PH3 profile in which the tropospheric mixing ratio was increased to 7 × 10-6 and the cutoff due to photodissociation was lowered to 300 mbar. These results are based on trial observations during performance verification of the LWS, and provide an indication of the results we expect to obtain when the spectrum of Saturn is measured comprehensively later in the mission.