Wed, JAN 22, 2020
SPEAKER: Dinko Milakovic (ESO, Garcing, DE)
TITLE: Preparing for the Extremely Large Telescope

ABSTRACT: The deployment of the high-resolution echelle spectrograph HIRES on the Extremely Large Telescope will facilitate important spectroscopic studies of exoplanets, stars and galaxies, as well as fundamental physics and cosmology. The success of these studies relies on a detailed understanding of all systematics that will limit the utility of future HIRES observations, such that their effects can be removed. This can be done using currently existing instrumentation, as will be presented in this talk. 
In the first part, I will talk about wavelength calibration of echelle spectrographs using Laser Frequency Comb (LFC) systems and how they can be used to remove effects from anomalies in physical pixel size of the detector, commonly used wavelength calibration methods, and flux-dependent spectroscopic velocity shifts. Uncorrected, these effects can mimic non-existent exoplanets and spoil measurements of fundamental constants and the redshift drift.
In the second part, I will talk about producing a set of legacy observations that can be used as benchmarks for HIRES. Two observations have already been taken: a HARPS spectrum of HE0515 and an ESPRESSO spectrum of J2123 in four telescope mode. The spectra are LFC calibrated and were analysed using a novel spectral modelling tool capable of autonomous decision-making through genetic algorithms and advanced statistical methods. This allowed us to measure the value of the fine structure constant in these two systems.

contact: Stefano Cristiani, Paolo Molaro