Retrieving the transmission spectrum of HD 209458b using CHOCOLATE: a new chromatic Doppler tomography technique star

• Type: Article in International Scientific Journal
• Date: 2021

Authors

Esparza Borges, E (Author) Other; Oshagh, M (Author) Other; Casasayas Barris, N (Author) Other; Palle, E (Author) Other; Chen, G (Author) Other; Morello, G (Author) Other; N.C. Santos (Author) FCUP; Seidel, JV (Author) Other; Sozzetti, A (Author) Other; Allart, R (Author) Other; Figueira, P (Author) Other; Bourrier, V (Author) Other; Lillo Box, J (Author) Other; Borsa, F (Author) Other; Osorio, MRZ (Author) Other; Tabernero, H (Author) Other; Demangeon, ODS (Author) Other; Adibekyan, V (Author) Other; Hernandez, JIG (Author) Other; Mehner, A (Author) Other; Prieto, CA (Author) Other; Di Marcantonio, P (Author) Other; Alibert, Y (Author) Other; Cristiani, S (Author) Other; Lo Curto, G (Author) Other; Martins, CJAP (Author) FCUP; Micela, G (Author) Other; Pepe, F (Author) Other; Rebolo, R (Author) Other; Sousa, SG (Author) FCUP; Mascareno, AS (Author) Other; Udry, S (Author) Other

Journal

Title: Astronomy and Astrophysics

Vol. 657

Final page: A23

ISSN: 0004-6361

Publisher: EDP Sciences

Indexing

ISI Web of Knowledge - 2 Citations

Scopus - 2 Citations

Other information

Authenticus ID: P-00V-WWK

DOI: 10.1051/0004-6361/202141826

Abstract (EN): Multiband photometric transit observations or low-resolution spectroscopy (spectro-photometry) are normally used to retrieve the broadband transmission spectra of transiting exoplanets in order to assess the chemical composition of their atmospheres. In this paper we present an alternative approach for recovering the broadband transmission spectra using chromatic Doppler tomography based on physical modeling through the SOAP tool: CHOCOLATE (CHrOmatiC line prOfiLe tomogrAphy TEchnique). To validate the method and examine its performance, we use observational data recently obtained with the ESPRESSO instrument to retrieve the transmission spectra of the archetypal hot Jupiter HD 209458b. Our findings indicate that the recovered transmission spectrum is in good agreement with the results presented in previous studies, which used different methodologies to extract the spectrum, achieving similar precision. We explored several atmospheric models and inferred from spectral retrieval that a model containing H2O and NH3 is the preferred scenario. The CHOCOLATE methodology is particularly interesting for future studies of exoplanets around young and active stars or moderate to fast rotating stars, considering SOAP's ability to model stellar active regions and the fact that the rotational broadening of spectral lines favors its application. Furthermore, CHOCOLATE will allow the broad transmission spectrum of a planet to be retrieved using high-S/N, high-resolution spectroscopy with the next generation of extremely large telescopes, where low-resolution spectroscopy will not always be accessible.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 12