Search Publications
Physical properties of asteroid Dimorphos as derived from the DART impact
Pajola, M.; Rossi, A.; Dotto, E. +39 more
On 26 September 2022, NASA's Double Asteroid Redirection Test (DART) mission successfully impacted Dimorphos, the natural satellite of the binary near-Earth asteroid (65803) Didymos. Numerical simulations of the impact provide a means to find the surface material properties and structures of the target that are consistent with the observed momentu…
A massive compact quiescent galaxy at z = 2 with a complete Einstein ring in JWST imaging
van Dokkum, Pieter; Conroy, Charlie; Brammer, Gabriel +2 more
One of the surprising results from the Hubble Space Telescope was the discovery that many of the most massive galaxies at redshift z ≈ 2 are very compact, having a half-light radius of only 1‑2 kpc. The interpretation is that massive galaxies formed inside out, with their cores largely in place by z ≈ 2 and approximately half of their present-day …
OH as a probe of the warm-water cycle in planet-forming disks
Gordon, Karl D.; Onaka, Takashi; Fuente, Asunción +51 more
Water is a key ingredient for the emergence of life as we know it. Yet, its destruction and reformation in space remain unprobed in warm gas (T > 300 K). Here we detect with the James Webb Space Telescope the emission of the hydroxyl radical (OH) from d203-506, a planet-forming disk exposed to external far-ultraviolet (FUV) radiation. These obs…
A benchmark JWST near-infrared spectrum for the exoplanet WASP-39 b
Zhang, X.; Heng, K.; May, E. M. +77 more
Observing exoplanets through transmission spectroscopy supplies detailed information about their atmospheric composition, physics and chemistry. Before the James Webb Space Telescope (JWST), these observations were limited to a narrow wavelength range across the near-ultraviolet to near-infrared, alongside broadband photometry at longer wavelength…
The broken-exponential radial structure and larger size of the Milky Way galaxy
Imig, Julie; Chen, Bingqiu; Wang, Tao +4 more
The radial structure of a galaxy is a fundamental property that reflects its growth and assembly history. Although it is straightforward to measure that of external galaxies, it is challenging for the Milky Way because of our inside perspective. Traditionally, the radial structure of the Milky Way has been assumed to be characterized by a single-e…
An abrupt change in the stellar spin-down law at the fully convective boundary
Angus, Ruth; Amard, Louis; See, Victor +2 more
Unlike partially convective stars such as the Sun, fully convective stars do not possess a radiative core. Whether a star needs this core to generate a solar-like magnetic dynamo is still unclear. Recent studies suggest fully and partially convective stars exhibit very similar period-activity relationships, hinting that dynamos generated by stars …
A departure from the mass-metallicity relation in merging galaxies due to an infall of metal-poor gas
Pérez-Díaz, Borja; Pérez-Montero, Enrique; Fernández-Ontiveros, Juan A. +2 more
Heavy element accumulation and stellar mass assembly are fundamental processes in the formation and evolution of galaxies. However, the key elements that govern them, such as gas accretion and outflow, are not fully understood. This is especially true for luminous and massive galaxies, which usually suffer strong feedback as massive outflows and l…
The metal-poor atmosphere of a potential sub-Neptune progenitor
Fortney, Jonathan J.; Désert, Jean-Michel; Petigura, Erik A. +12 more
Young transiting exoplanets offer a unique opportunity to characterize the atmospheres of freshly formed and evolving planets. We present the transmission spectrum of V1298 Tau b, a 23-Myr-old warm Jupiter-sized (0.91 ± 0.05 RJ, where RJ is the radius of Jupiter) planet orbiting a pre-main-sequence star. We detect a mostly cl…
Enrichment by extragalactic first stars in the Large Magellanic Cloud
Li, Ting S.; Frebel, Anna; Simon, Joshua D. +8 more
The Large Magellanic Cloud (LMC) is the Milky Way's most massive satellite galaxy, which only recently (~2 billion years ago) fell into our Galaxy. As stellar atmospheres preserve the composition of their natal cloud, the LMC's recent infall makes its most ancient, metal-deficient (`low-metallicity') stars unique windows into early star formation …
Multi-source connectivity as the driver of solar wind variability in the heliosphere
D'Amicis, Raffaella; Long, David M.; Schühle, Udo +18 more
The ambient solar wind that fills the heliosphere originates from multiple sources in the solar corona and is highly structured. It is often described as high-speed, relatively homogeneous, plasma streams from coronal holes and slow-speed, highly variable, streams whose source regions are under debate. A key goal of ESA/NASA's Solar Orbiter missio…