{"about":{"site":"https://codewithpapers.app","non_affiliation":"Code with Papers and Syntology are not affiliated with, endorsed by, or sponsored by Papers with Code, Meta, or the pwc-archive mirror.","licence":"CC BY-SA 4.0","licence_url":"https://creativecommons.org/licenses/by-sa/4.0/legalcode","attribution":"https://codewithpapers.app/attribution","modified":"archive material modified by Syntology; see the attribution page"},"url":"/paper/high-resolution-emission-spectroscopy","title":"High-resolution emission spectroscopy retrievals of MASCARA-1b with CRIRES+: Strong detections of CO, H$_2$O and Fe emission lines and a C$/$O consistent with solar","arxiv_id":"2308.07157","date":"2023-08-14","proceeding":null,"authors":["Swaetha Ramkumar","Neale P. Gibson","Stevanus K. Nugroho","Cathal Maguire","Mark Fortune"],"abstract":"The characterization of exoplanet atmospheres has proven to be successful using high-resolution spectroscopy. Phase curve observations of hot/ultra-hot Jupiters can reveal their compositions and thermal structures, thereby allowing the detection of molecules and atoms in the planetary atmosphere using the cross-correlation technique. We present pre-eclipse observations of the ultra-hot Jupiter, MASCARA-1b, observed with the recently upgraded CRIRES+ high-resolution infrared spectrograph at the VLT. We report a detection of $\\rm Fe$ ($\\approx$8.3$\\sigma$) in the K-band and confirm previous detections of $\\rm CO$ (>15$\\sigma$) and $\\rm H_2O$ (>10$\\sigma$) in the day-side atmosphere of MASCARA-1b. Using a Bayesian inference framework, we retrieve the abundances of the detected species and constrain planetary orbital velocities, $T$-$P$ profiles, and the carbon-to-oxygen ratio ($\\rm C/O$). A free retrieval results in an elevated $\\rm CO$ abundance ($\\log_{10}$($\\chi_{\\rm{{}^{12}CO}}$) = $-2.85^{+0.57}_{-0.69}$), leading to a super-solar $\\rm C/O$ ratio. More realistically, allowing for vertically-varying chemistry in the atmosphere by incorporating a chemical-equilibrium model results in a $\\rm C/O$ of $0.68^{+0.12}_{-0.22}$ and a metallicity of $[\\rm M/H] = 0.62^{+0.28}_{-0.55}$, both consistent with solar values. Finally, we also report a slight offset of the $\\rm Fe$ feature in both K$_{\\rm p}$ and v$_{\\rm sys}$ that could be a signature of atmospheric dynamics. Due to the 3D structure of exoplanet atmospheres and the exclusion of time/phase dependence in our 1D forward models, further follow-up observations and analysis are required to confirm or refute this result.","url_abs":"https://arxiv.org/abs/2308.07157v1","url_pdf":"https://arxiv.org/pdf/2308.07157v1.pdf","source":{"archive":"pwc-archive (Hugging Face), CC BY-SA 4.0","snapshot":"2025-07-28","licence_url":"https://creativecommons.org/licenses/by-sa/4.0/legalcode","row_kind":"links_only","authors_date_abstract":"arXiv metadata, CC0 1.0 (https://info.arxiv.org/help/license), from the Kaggle arXiv metadata snapshot of 2026-09-12"},"code_links":[{"paper_slug":"high-resolution-emission-spectroscopy","repo_url":"https://github.com/exoclime/FastChem","is_official":1,"mentioned_in_paper":1,"mentioned_in_github":0,"framework":"none","reach":{"status":"ok","spdx":"GPL-3.0"}}],"tasks":[],"methods":[],"datasets_introduced":[],"methods_introduced":[],"results":[],"syntology":{"atlas_url":null,"mcp":null,"developers":"https://syntology.ai/developers"},"arxiv_metadata":null,"syntology_extracted_results":null}