Gilles Otten

Post-Doctoral Researcher

Coupling SPHERE and CRIRES+ for the improved characterization of exoplanetary atmospheres

High Contrast Imaging -- Spectroscopy -- Exoplanets -- Coronagraphy -- Adaptive Optics

Current Research Summary:

Since the first detection of a directly imaged exoplanet in 2004, over a dozen of planets have been detected. In recent years dedicated high resolution direct imagers such as SPHERE and GPI have detected many more disks and companions around young nearby stars. With their AO systems and coronagraphs they can image faint planets as well as planets close to the star.

While spectrometers can be used to analyze the atmospheres of these exoplanets their performance is limited in wavelength range and spectral resolution.

At LAM we are developing the HiRISE instrument, designed to couple the direct imager SPHERE with the high resolution spectrograph CRIRES+, thereby combining the quality of both instruments and allowing the characterization of targets at high contrast and high spectral resolution.

My work focuses on performance simulations of this coupling for the known directly imaged planets. We simulate the measured planetary and stellar signal with realistic noise and throughput values using our own Python code. The signal to noise of detecting certain molecular species (H2O, CH4, CO, etc.) in the atmospheres are extracted from these spectra with a cross-correlation approach.

Using these simulations we evaluate the performance increase of this combination of instruments with respect to using only CRIRES+, additionally the impact of design choices is simulated and used to guide the optical and mechanical design of HiRISE.

Prior Research:

Postdoc at Leiden Observatory (2016-2017) on construction and commissioning of transiting exoplanet hunter Multi-site All-Sky CAmeRA (MASCARA) at La Silla

PhD at Leiden Observatory (2011-2016) on prototyping broadband coronagraphs (vAPPs) using liquid crystals

MSc at Leiden University (2009-2011) on feasibility of detection transiting exoplanets with consumer cameras (DSLRs)