Mathis Houllé

Interferometry with GRAVITY at the VLTI has brought an impressive astrometric precision and high-quality near-infrared spectra for exoplanets. Repeating this experience in the mid-infrared with MATISSE has recently been made possible thanks to its combination with the fringe tracker of GRAVITY (called GRA4MAT). Using this new capability, I am working on the extraction of the L-band spectrum of β Pictoris b.

The shape of the hydrogen emission lines of young substellar companions is intricately linked to its ongoing accretion process. Characterizing these lines at high resolution can thus give precious constraints on this process and the forming companion itself. I am the PI of several accepted ESO programmes with ESPRESSO, the ultra-high-resolution fiber-fed spectrograph of the VLT, which aim at resolving for the first time at high spectral resolution the Hα line of protoplanets.

Simulations of exoplanet detection with the high-contrast module of HARMONI, the first-light integral field spectrograph of ESO's ELT. We used the molecular mapping technique, which offers a clear gain over classical high-contrast imaging techniques at the spectral resolution of HARMONI (up to R=18000). HARMONI will greatly push the limits of the current high-contrast imagers, and reach dense regions of planetary populations inaccessible at the moment. Link to article.