Search Publications
A dusty star-forming galaxy at z = 6 revealed by strong gravitational lensing
Ivison, R. J.; Zavala, Jorge A.; Smith, Matthew W. L. +29 more
Since their discovery, submillimetre-selected galaxies1,2 have revolutionized the field of galaxy formation and evolution. From the hundreds of square degrees mapped at submillimetre wavelengths3-5, only a handful of sources have been confirmed to lie at z > 5 (refs 6-10) and only two at z ≥ 6 (refs 11,12
Detection of hydrogen sulfide above the clouds in Uranus's atmosphere
Fletcher, Leigh N.; Bézard, Bruno; Irwin, Patrick G. J. +4 more
Visible-to-near-infrared observations indicate that the cloud top of the main cloud deck on Uranus lies at a pressure level of between 1.2 bar and 3 bar. However, its composition has never been unambiguously identified, although it is widely assumed to be composed primarily of either ammonia or hydrogen sulfide (H2S) ice. Here, we prese…
Supervised machine learning for analysing spectra of exoplanetary atmospheres
Heng, Kevin; Fisher, Chloe; Márquez-Neila, Pablo +1 more
The use of machine learning is becoming ubiquitous in astronomy1-3, but remains rare in the study of the atmospheres of exoplanets. Given the spectrum of an exoplanetary atmosphere, a multi-parameter space is swept through in real time to find the best-fit model4-6. Known as atmospheric retrieval, this technique originates in…
Catastrophic disruptions as the origin of bilobate comets
Richardson, Derek C.; Jutzi, Martin; Michel, Patrick +3 more
Several comets observed at close range have bilobate shapes1, including comet 67P/Churyumov-Gerasimenko (67P/C-G), which was imaged by the European Space Agency's Rosetta mission2,3. Bilobate comets are thought to be primordial because they are rich in supervolatiles (for example, N2 and CO) and have a low bulk den…
Detection of a westward hotspot offset in the atmosphere of hot gas giant CoRoT-2b
Deming, Drake; Fortney, Jonathan J.; Knutson, Heather A. +9 more
Short-period planets exhibit day-night temperature contrasts of hundreds to thousands of kelvin. They also exhibit eastward hotspot offsets whereby the hottest region on the planet is east of the substellar point1; this has been widely interpreted as advection of heat due to eastward winds2. We present thermal phase observati…
Two peculiar fast transients in a strongly lensed host galaxy
Sharon, K.; Diego, J. M.; Molino, A. +32 more
A massive galaxy cluster can serve as a magnifying glass for distant stellar populations, as strong gravitational lensing magnifies background galaxies and exposes details that are otherwise undetectable. In time-domain astronomy, imaging programmes with a short cadence are able to detect rapidly evolving transients, previously unseen by surveys d…
Three-dimensional motions in the Sculptor dwarf galaxy as a glimpse of a new era
Massari, D.; Helmi, A.; Brown, A. G. A. +3 more
The three-dimensional motions of stars in small galaxies beyond our own are minute, yet they are crucial for understanding the nature of gravity and dark matter1,2. Even for the dwarf galaxy Sculptor—one of the best-studied systems, which is inferred to be strongly dark matter dominated3,4—there are conflicting reports5-…
The nature of the lithium enrichment in the most Li-rich giant star
Zhao, Gang; Gao, Qi; Yan, Hong-Liang +13 more
About 1% of giant stars1 have anomalously high Li abundances (ALi) in their atmospheres, conflicting directly with the prediction of standard stellar evolution models2. This finding makes the production and evolution of Li in the Universe intriguing, not only in the sense of Big Bang nucleosynthesis3,4 o…
Measurement of the primordial helium abundance from the intergalactic medium
Fumagalli, Michele; Cooke, Ryan J.
Almost every helium atom in the Universe was created just a few minutes after the Big Bang through a process commonly referred to as Big Bang nucleosynthesis1,2. The amount of helium that was made during Big Bang nucleosynthesis is determined by combining particle physics and cosmology3. The current leading measures of the pr…
Non-thermal X-rays from colliding wind shock acceleration in the massive binary Eta Carinae
Hamaguchi, Kenji; Corcoran, Michael F.; Russell, Christopher M. P. +9 more
Cosmic-ray acceleration has been a long-standing mystery1,2 and, despite more than a century of study, we still do not have a complete census of acceleration mechanisms. The collision of strong stellar winds in massive binary systems creates powerful shocks that have been expected to produce high-energy cosmic rays through Fermi acceler…