Gas Giants

First Light of VLT/HiRISE: High-resolution Spectroscopy Of Young Giant Exoplanets

By Keith Cowing
Status Report
November 17, 2023
Filed under , , , , , ,
First Light of VLT/HiRISE: High-resolution Spectroscopy Of Young Giant Exoplanets
Implementation of the FIM inside the IFS arm of SPHERE. On the left drawing, the SPHERE components are labelled in black, while the FIM components are labelled in red. The inset in the top right shows the components of the core optics bench. The light path in the system is fully illustrated in Vigan et al. (2022b, their Fig. 3). The picture on the right shows the FIM at the end of the installation in SPHERE. The IFS Lyot wheel is visible in the bottom left of the picture. — astro-ph.EP

A major endeavor of this decade is the direct characterization of young giant exoplanets at high spectral resolution to determine the composition of their atmosphere and infer their formation processes and evolution.

Such a goal represents a major challenge owing to their small angular separation and luminosity contrast with respect to their parent stars. Instead of designing and implementing completely new facilities, it has been proposed to leverage the capabilities of existing instruments that offer either high contrast imaging or high dispersion spectroscopy, by coupling them using optical fibers.

In this work we present the implementation and first on-sky results of the HiRISE instrument at the very large telescope (VLT), which combines the exoplanet imager SPHERE with the recently upgraded high resolution spectrograph CRIRES using single-mode fibers. The goal of HiRISE is to enable the characterization of known companions in the H band, at a spectral resolution of the order of R=λ/Δλ=100000, in a few hours of observing time. We present the main design choices and the technical implementation of the system, which is constituted of three major parts: the fiber injection module inside of SPHERE, the fiber bundle around the telescope, and the fiber extraction module at the entrance of CRIRES.

We also detail the specific calibrations required for HiRISE and the operations of the instrument for science observations. Finally, we detail the performance of the system in terms of astrometry, temporal stability, optical aberrations, and transmission, for which we report a peak value of ∼3.9% based on sky measurements in median observing conditions. Finally, we report on the first astrophysical detection of HiRISE to illustrate its potential.

A. Vigan, M. El Morsy, M. Lopez, G. P. P. L. Otten, J. Garcia, J. Costes, E. Muslimov, A. Viret, Y. Charles, G. Zins, G. Murray, A. Costille, J. Paufique, U. Seemann, M. Houllé, H. Anwand-Heerwart, M. Phillips, A. Abinanti, P. Balard, I. Baraffe, J.-A. Benedetti, P. Blanchard, L. Blanco, J.-L. Beuzit, E. Choquet, P. Cristofari, S. Desidera, K. Dohlen, R. Dorn, T. Ely, E. Fuenteseca, N. Garcia, M. Jaquet, F. Jaubert, M. Kasper, J. Le Merrer, A.-L. Maire, M. N’Diaye, L. Pallanca, D. Popovic, R. Pourcelot, A. Reiners, S. Rochat, C. Sehim, R. Schmutzer, A. Smette, N. Tchoubaklian, P. Tomlinson, J. Valenzuela Soto

Comments: 17 pages, 15 figures, 3 tables. Submitted to A&A on 19 September 2023
Subjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); Earth and Planetary Astrophysics (astro-ph.EP)
Cite as: arXiv:2309.12390 [astro-ph.IM] (or arXiv:2309.12390v1 [astro-ph.IM] for this version)
Submission history
From: Arthur Vigan
[v1] Thu, 21 Sep 2023 18:00:01 UTC (2,802 KB)

Explorers Club Fellow, ex-NASA Space Station Payload manager/space biologist, Away Teams, Journalist, Lapsed climber, Synaesthete, Na’Vi-Jedi-Freman-Buddhist-mix, ASL, Devon Island and Everest Base Camp veteran, (he/him) 🖖🏻