Speaker
Description
The next generation of ground-based telescopes, which complement the space missions, are aimed at HR (R ~ 100,000) studies. Ground-based high resolution Doppler spectroscopy (HRS), pioneered by Snellen, has been used to characterise the atmospheres of a growing number of exoplanets in recent years. None of this is possible without the necessary laboratory data. While spectroscopic and other data needs for studies of Earth-clone exoplanets are well met by databases constructed for studying our own atmosphere, such as HITRAN, this is not the case for those exoplanets which will be the first exoplanets to be characterised. These planets are hot and most are subject to strong bombardment by starlight (and presumably stellar winds). Such studies require data on hot molecules which are not generally available and which are in many cases not easily amenable to laboratory experiments. In particular, current developments in exoplanetary observations are fueling the requirement for HR data. This creates new challenges for laboratory spectroscopy projects like ExoMol, which have been mainly concerned with completeness (important for low resolution-based retrievals) rather than HR studies. The field of the HRS of exoplanets is growing extremely fast and urgently demanding high precision molecular data. Failures to detect molecules in atmospheres of exoplanets can often be attributed to the lack of the underlying quality of the line positions.
The ExoMol database contains extensive line lists for approximately 80 molecules, in most cases for several isotopically substituted variants ("isotopologues"), with over 700 billion molecular transitions and two formal releases. The current ExoMol activity aims at providing high accuracy spectroscopic data for high resolution studies of exoplanetary atmospheres. Novel theoretical techniques are being used to provide similar high accuracy line lists for isotopically substituted species and to generate pressure broadening data.
