Exoplanets and Stellar Physics

Abstract:

The technique of integral field spectroscopy,: which provides simultaneous spectra for each pixel of a contiguous two-dimensional field of view, holds tremendous promise for improving our ability to study circumstellar environments. The technique becomes especially important at near infrared wavelengths, where rapid changes in the night sky background level limit the use of standard scanning techniques. In addition, combining the capabilities of adaptive optics systems with near infrared integral field spectrographs provides an unique way to enhance-spatial resolution for ground based observations. We present the technique of integral field spectroscopy, with special emphasis on the near infrared, and illustrate future developments by describing SINFONI, an adaptive optics assisted near infrared integral field spectrometer for the ESO VLT.

Abstract:

We propose to build a NIR imager/spectrograph for the LET which will support (1) seeing and diffraction limited direct imaging, (2) seeing and diffraction limited long-slit spectroscopy, (3) integral field spectroscopy and (4) tin small fields) OH-suppressed imaging of very faint objects. The instrument will cover the zJHK spectral bands with optimization for the K band. Therefore the optics will be cold (77 K). Whether the wavelength coverage can be extended to 5 mu without seriously compromising the K-band performance will be investigated during the design phase. At present a 2048 x 2048 HgCdTe array is foreseen as detector. Space will be reserved for the possibility of adding a (cold) multiple object spectroscopy unit. The feasibility of such a device will be investigated in parallel to the development of the main instrument. Six German institutes will cooperate to develop this LBT instrument.

Abstract:

We present the results of our subarcsecond resolution interferometric observations of the 1.3 mm CO J = 2-->1 line in the luminous merger NGC 6240. Roughly half of the CO flux is contained in a rotating and highly turbulent thick disk centered between the two radio and near-infrared nuclei. In this disk the molecular gas has velocity widths which reach FWZP line widths of up to 1000 km s(-1). The mass of this gas concentration makes up between 30%-70% of the dynamical mass in this region. NGC 6240 may be in an earlier merging stage than typical ULIRGs such as Arp 220. We compare these results from NGC 6240 with those of other luminous, gas-rich interacting galaxies and mergers.