ESPRESSO high resolution transmission spectroscopy of WASP-76b
Abstract
Aims. We report on ESPRESSO high-resolution transmission spectroscopic observations of two primary transits of the highly-irradiated, ultra-hot Jupiter-size planet WASP-76b. We investigate the presence of several key atomic and molecular features of interest that may reveal the atmospheric properties of the planet. Methods. We extracted two transmission spectra of WASP-76b with R approx 140,000 using a procedure that allowed us to process the full ESPRESSO wavelength range (3800-7880 A) simultaneously. We observed that at a high signal-to-noise ratio, the continuum of ESPRESSO spectra shows wiggles that are likely caused by an interference pattern outside the spectrograph. To search for the planetary features, we visually analysed the extracted transmission spectra and cross-correlated the observations against theoretical spectra of different atomic and molecular species. Results. The following atomic features are detected: Li I, Na I, Mg I, Ca II, Mn I, K I, and Fe I. All are detected with a confidence level between 9.2 sigma (Na I) and 2.8 sigma (Mg I). We did not detect the following species: Ti I, Cr I, Ni I, TiO, VO, and ZrO. We impose the following 1 sigma upper limits on their detectability: 60, 77, 122, 6, 8, and 8 ppm, respectively. Conclusions. We report the detection of Li I on WASP-76b for the first time. In addition, we found the presence of Na I and Fe I as previously reported in the literature. We show that the procedure employed in this work can detect features down to the level of ~ 0.1 % in the transmission spectrum and ~ 10 ppm by means of a cross-correlation method. We discuss the presence of neutral and singly ionised features in the atmosphere of WASP-76b.
Keywords
Cite
@article{arxiv.2011.12197,
title = {ESPRESSO high resolution transmission spectroscopy of WASP-76b},
author = {H. M. Tabernero and M. R. Zapatero Osorio and R. Allart and F. Borsa and N. Casasayas-Barris and O. Demangeon and D. Ehrenreich and J. Lillo-Box and C. Lovis and E. Pallé and S. G. Sousa and R. Rebolo and N. C. Santos and F. Pepe and S. Cristiani and V. Adibekyan and C. Allende Prieto and Yann Alibert and S. C. C. Barros and F. Bouchy and V. Bourrier and V. D'Odorico and X. Dumusque and J. P. Faria and P. Figueira and R. Génova Santos and J. I. González Hernández and S. Hojjatpanah and G. Lo Curto and B. Lavie and C. J. A. P. Martins and J. H. C. Martins and A. Mehner and G. Micela and P. Molaro and N. J. Nunes and E. Poretti and J. V. Seidel and A. Sozzetti and A. Suárez Mascareño and S. Udry and M. Aliverti and M. Affolter and D. Alves and M. Amate and G. Avila and T. Bandy and W. Benz and A. Bianco and C. Broeg and A. Cabral and P. Conconi and J. Coelho and C. Cumani and S. Deiries and H. Dekker and B. Delabre and A. Fragoso and M. Genoni and L. Genolet and I. Hughes and J. Knudstrup and F. Kerber and M. Landoni and J. L. Lizon and C. Maire and A. Manescau and P. Di Marcantonio and D. Mégevand and M. Monteiro and M. Monteiro and M. Moschetti and E. Mueller and A. Modigliani and L. Oggioni and A. Oliveira and G. Pariani and L. Pasquini and J. L. Rasilla and E. Redaelli and M. Riva and S. Santana-Tschudi and P. Santin and P. Santos and A. Segovia and D. Sosnowska and P. Spanò and F. Tenegi and O. Iwert and A. Zanutta and F. Zerbi},
journal= {arXiv preprint arXiv:2011.12197},
year = {2021}
}
Comments
20 pages, 19 figures, accepted for publication in Astronomy and Astrophysics