Objectif
"The search for extrasolar planets is moving into the domain of Earth-like, habitable planets with more precise measurement techniques and a focus on low-mass, very cool stars. New spectrographs are being developed with the goal to find Earth-like planets in the habitable zones of stars other than the Sun. Extensive photometric programs, both ground- and space-based are running and being planned to discover transiting planets particularly useful for detailed investigation of exo-planetary atmospheres. For the characterization of exo-planets, and to confirm the planetary status of transit candidates, high-precision radial velocity measurements (m/s) are required, in particular at near-infrared (NIR) wavelengths to discover Earth-like planets around low-mass stars. The largest obstacle for NIR programs is currently the lack of reliable wavelength standards. Potential calibration sources include absorption cells, gas emission lamps, and Fabry-Perot (FP) etalons. In most cases, detailed NIR characterization is still lacking. A very promising source is the Laser frequency comb (LFC), but the LFC signal paradoxically needs to be degenerated to be useful for astronomical spectrographs because spectral line density is usually too high. It is currently not clear whether the LFC can become a viable calibration scheme, in particular for programs carried out at 4m-class telescopes. I propose to systematically investigate wavelength calibration sources with a focus on NIR wavelengths and to develop wavelength calibration sources for NIR wavelengths. The development is of fundamental nature providing new strategies for the upcoming generation of NIR high-precision spectrographs. I suggest a new mechanism in which a FP should be coupled to a double-laser PDH mechanism providing reliable wavelength reference. Calibration lamps filled with UNe or CN are promising alternative sources of calibration lines and should be studied in detail."
Champ scientifique
Appel à propositions
ERC-2011-StG_20101014
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Régime de financement
ERC-SG - ERC Starting GrantInstitution d’accueil
37073 Gottingen
Allemagne