Search Publications
The nature of an ultra-faint galaxy in the cosmic dark ages seen with JWST
Santini, Paola; Castellano, Marco; Fontana, Adriano +44 more
In the first billion years after the Big Bang, sources of ultraviolet (UV) photons are believed to have ionized intergalactic hydrogen, rendering the Universe transparent to UV radiation. Galaxies brighter than the characteristic luminosity L* (refs. 1,2) do not provide enough ionizing photons to drive this cosmic reionization. Fainter …
Ejecta from the DART-produced active asteroid Dimorphos
Granvik, Mikael; Kolokolova, Ludmilla; Weaver, Harold A. +61 more
Some active asteroids have been proposed to be formed as a result of impact events1. Because active asteroids are generally discovered by chance only after their tails have fully formed, the process of how impact ejecta evolve into a tail has, to our knowledge, not been directly observed. The Double Asteroid Redirection Test (DART) miss…
Carbonaceous dust grains seen in the first billion years of cosmic time
Chevallard, Jacopo; Carniani, Stefano; D'Eugenio, Francesco +39 more
Large dust reservoirs (up to approximately 108 M⊙) have been detected1-3 in galaxies out to redshift z ≃ 8, when the age of the Universe was only about 600 Myr. Generating substantial amounts of dust within such a short timescale has proven challenging for theories of dust formation4,5 and has prompted t…
A long-period radio transient active for three decades
de Martino, D.; Heywood, I.; Rea, N. +22 more
Several long-period radio transients have recently been discovered, with strongly polarized coherent radio pulses appearing on timescales between tens to thousands of seconds1,2. In some cases, the radio pulses have been interpreted as coming from rotating neutron stars with extremely strong magnetic fields, known as magnetars; the orig…
Detection of phosphates originating from Enceladus's ocean
Postberg, Frank; Sekine, Yasuhito; Glein, Christopher R. +13 more
Saturn's moon Enceladus harbours a global1 ice-covered water ocean2,3. The Cassini spacecraft investigated the composition of the ocean by analysis of material ejected into space by the moon's cryovolcanic plume4-9. The analysis of salt-rich ice grains by Cassini's Cosmic Dust Analyzer10 enabled inferenc…
Water in the terrestrial planet-forming zone of the PDS 70 disk
Waters, L. B. F. M.; Olofsson, G.; Abergel, A. +42 more
Terrestrial and sub-Neptune planets are expected to form in the inner (less than 10 AU) regions of protoplanetary disks1. Water plays a key role in their formation2-4, although it is yet unclear whether water molecules are formed in situ or transported from the outer disk5,6. So far Spitzer Space Telescope observat…
Vanadium oxide and a sharp onset of cold-trapping on a giant exoplanet
Kesseli, Aurora Y.; Kasper, David; Bean, Jacob L. +15 more
The abundance of refractory elements in giant planets can provide key insights into their formation histories1. Owing to the low temperatures of the Solar System giants, refractory elements condense below the cloud deck, limiting sensing capabilities to only highly volatile elements2. Recently, ultra-hot giant exoplanets have…
Methane throughout the atmosphere of the warm exoplanet WASP-80b
Fortney, Jonathan J.; Boyer, Martha L.; Bell, Taylor J. +12 more
The abundances of main carbon- and oxygen-bearing gases in the atmospheres of giant exoplanets provide insights into atmospheric chemistry and planet formation processes1,2. Thermochemistry suggests that methane (CH4) should be the dominant carbon-bearing species below about 1,000 K over a range of plausible atmospheric compo…
Stellar initial mass function varies with metallicity and time
Tian, Hao; Fu, Xiaoting; Li, Jiadong +4 more
Most structural and evolutionary properties of galaxies strongly rely on the stellar initial mass function (IMF), namely the distribution of the stellar mass formed in each episode of star formation1-4. The IMF shapes the stellar population in all stellar systems, and so has become one of the most fundamental concepts of modern astronom…
Formation of the methyl cation by photochemistry in a protoplanetary disk
Gordon, Karl D.; Martin-Drumel, Marie-Aline; Onaka, Takashi +53 more
Forty years ago, it was proposed that gas-phase organic chemistry in the interstellar medium can be initiated by the methyl cation CH3+ (refs. 1-3), but so far it has not been observed outside the Solar System4,5. Alternative routes involving processes on grain surfaces have been invoked6,7. H…