The future of high-resolution UV spectroscopy: Science with a UV Échelle spectrograph on the Habitable Worlds Observatory, or a dedicated mission
Year: 2026
Type: preprint
Abstract: High-resolution UV spectroscopy serves a diversity of science cases, from small bodies to planets, stars, and galaxies, but is currently limited to the Hubble Space Telescope and bright targets. Major advances require increasing sensitivity by at least one order of magnitude. Here we present the UV science cases for PEGASUS (Planets, Earths, Galaxies, And Stars UV Spectrograph), a UV Échelle high-resolution spectrograph concept, with $R = λ/δλ\sim 100\,000$ (full range 10 000-140 000) and covering 90--400 nm, with a foreseen extension to at least 800 nm. PEGASUS is ideally suited for the Habitable Worlds Observatory (HWO), enabling transformative science across the UV/optical wavelength ranges. PEGASUS will be unique in high sensitivity (effective area) and high spectral resolution -- an uncharted territory -- as well as robustness, thanks to the simplicity of its design. Its UV science cases include: I) Formation and evolution of planets and their habitability: properties of exoplanets and atmospheres, protoplanetary disks, Solar System bodies; II) Stellar lives and deaths at their extremes: the first stars and the origin of the elements, compact and massive stars, Supernovae; III) Gas and metals in the baryon cycle of galaxies: the interstellar, circumgalactic, and intergalactic medium and their roles in galaxy growth. These are essential for the Astro Decadal 2020 Survey, Voyage 2050, and HWO. While this paper focuses on high-impact science enabled by UV high-resolution spectroscopy, PEGASUS will extend into the optical regime and lower spectral resolution, making it a multi-purpose, widely used, workhorse spectrograph for HWO.
Source: arXiv (Cornell University)
Authors: De Cia, Annalisa, Cont, David, Heng, Kevin, Gänsicke, Boris, Grupp, Frank, Bender, Ralf, Lamprecht, Helena, Cashman, Frances H., Chen, Hsiao-Wen, D'Odorico, Valentina, France, Kevin, Fox, Andrew, Hoeijmakers, Jens, Ikoma, Masahiro, Jacobson-Galán, Wynn, Johnson, Sean D., Kasliwal, Mansi, Kameda, Shingo, Kulkarni, Varsha, Manara, Carlo F., Oklopčić, Antonija, Opitom, Cyrielle, Oskinova, Lidia, Pala, Anna F., Roederer, Ian U., Schneider, P. Christian, Scicluna, Peter, Welty, Daniel E., Zeegers, Sascha, Sierra, Abel de Burgos, García, Miriam, Kim, Avery, Konstantopoulou, Christina, Maiolino, Roberto, Pauli, Daniel, Ramburuth-Hurt, Tanita, Richter, Philipp, Sander, Andreas A. C., Shenar, Tomer, Simón-Díaz, Sergio, Telford, O. Grace, Velichko, Anna
Institutions: European Southern Observatory, Ludwig-Maximilians-Universität München, University of Warwick, Max Planck Institute for Extraterrestrial Physics, Space Telescope Science Institute, Presbyterian College, University of Chicago, Trieste Astronomical Observatory, Institute for Fundamental Physics of the Universe, National Institute for Astrophysics, Lund University, California Institute of Technology, University of Michigan, Rikkyo University, Japan Aerospace Exploration Agency, Institute of Space and Astronautical Science, University of South Carolina, University of Amsterdam, Royal Observatory, University of Edinburgh, University of Potsdam, North Carolina State University, Universität Hamburg, Lyon 1 Université, Space Science Institute, Institute of Astronomy and Astrophysics, Academia Sinica, University of Hertfordshire, University of Cambridge, Centre de Recherche Astrophysique de Lyon, Centro de Astrobiología, European Southern Observatory, Space Research Organisation Netherlands, Academia Sinica, European Space Agency
Language: English
Subfield: Instrumentation
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7212188713