PhD position in exoplanets and near-infrared spectroscopy

Applications are invited for a PhD position in the exoplanet group at the Department of Astronomy of the University of Geneva, to start Fall 2020. Candidates from underrepresented groups in Astronomy are strongly encouraged to apply. All materials should be received by February the 20th for full consideration.

The successful applicant will work as a member of the SCORE research team led by Prof. Xavier Dumusque, and will join the vibrant exoplanet group at the department of astronomy, composed of about 50 PhD students and scientists, specialised in radial-velocity measurements, transit photometry, exoplanet atmosphere characterization, direct imaging as well as instrumentation. The exoplanet group is also part of the Switzerland-wide network PlanetS (http://nccr-planets.ch/), specialised in all different fields of planetary sciences with a large focus on exoplanets.

Overview
The ERC-funded SCORE project (Signal Correction to Reveal other Earths) aims at probing the main limitations to the detection of Earth-like planets using extreme precision radial-velocity measurements. The SCORE project relies on the unprecedented data obtained by two solar telescopes, connected to the HARPS and HARPS-N spectrographs, which allow to obtain sub-meter-per-second radial-velocity measurements of the Sun every possible day. Analysing such data is crucial to understand and find correction techniques to mitigate the impact of the different astrophysical and instrumental signals perturbing radial-velocity measurements and preventing the detection of other Earths. Any new technique developed in this framework will then be tested on the extensive RV data sets available in Geneva, coming from in-house instruments like CORALIE, HARPS, HARPS-N, ESPRESSO and NIRPS

PhD project: Solar radial-velocities in the near-infrared with NIRPS
Radial-velocities in the near-infrared are extremely interesting to search for the tiny signature of Earth-like planets as stellar activity signals are supposed to be smaller than in the visible. However, reaching the meter-per-second precision in the near-infrared is an extremely challenging task, due to tellurics absorption, low radial-velocity content, and systematics induced by infrared CCDs. By the end of 2020, the NIRPS spectrograph will be installed in La Silla and the HELIOS solar telescope will feed sunlight in the instrument every possible day, therefore delivering unprecedented precise radial-velocity measurements in the near-infrared.

The selected PhD candidate is planned to work on 1) studying the impact of tellurics on radial-velocity measurements and developing optimal correction techniques, 2) investigating the use of chromaticity to mitigate stellar activity signals and 3) investigating the use of Zeeman broadening to correct for stellar activity signals. The candidate will also have the opportunity to investigate other aspects of near-infrared spectroscopy and to be involved in the NIRPS team.

Candidates will be evaluated on:
1) experience with telluric contamination in radial-velocity measurements,
2) experience with high-resolution spectroscopy and
3) commitment to fostering an inclusive research environment.

The duration of the appointment is for four years. Interested candidates should submit via email to [email protected], in a single PDF, the following material:
1) a cover letter that summarises the candidate's experience in the different evaluation criteria listed above, as well as the candidate’s motivation to pursue a PhD (no more than two pages)
2) a CV with publications
3) the name with position and email address of three persons of reference that could be contacted.