Search Publications
Unveiling the population of dual and lensed active galactic nuclei at sub-arcsec separations
Marconi, A.; Pancino, E.; Nardini, E. +12 more
All cosmological models of structure formation predict the existence of a widespread population of dual supermassive black holes in-spiralling inside their common host galaxy, eventually merging and giving rise to intense gravitational waves. These systems can be identified as dual active galactic nuclei (AGNs) at kiloparsec separations, but only …
Nested dust shells around the Wolf-Rayet binary WR 140 observed with JWST
Hamaguchi, Kenji; Corcoran, Michael F.; Morris, Mark R. +29 more
Massive colliding-wind binaries that host a Wolf-Rayet (WR) star present a potentially important source of dust and chemical enrichment in the interstellar medium. However, the chemical composition and survival of dust formed from such systems is not well understood. The carbon-rich Wolf-Rayet binary WR 140 presents an ideal astrophysical laborato…
Definitive upper bound on the negligible contribution of quasars to cosmic reionization
Ho, Luis C.; Fan, Xiaohui; Jiang, Linhua +7 more
Cosmic (hydrogen) reionization marks one of the major phase transitions of the universe at redshift z ≥ 6. During this epoch, hydrogen atoms in the intergalactic medium were ionized by Lyman continuum (LyC) photons. However, it remains challenging to identify the major sources of the LyC photons responsible for reionization. In particular, individ…
Estimate of the carbon footprint of astronomical research infrastructures
Hughes, Annie; Martin, Pierrick; Knödlseder, Jürgen +4 more
The carbon footprint of astronomical research is an increasingly topical issue with first estimates of research institute and national community footprints having recently been published. As these assessments have typically excluded the contribution of astronomical research infrastructures, we complement these studies by providing an estimate of t…
A fast-rising tidal disruption event from a candidate intermediate-mass black hole
Rest, A.; Angus, C. R.; Foley, R. J. +36 more
Massive black holes (BHs) at the centres of massive galaxies are ubiquitous. The population of BHs within dwarf galaxies, on the other hand, is not yet known. Dwarf galaxies are thought to harbour BHs with proportionally small masses, including intermediate-mass BHs, with masses 102 < MBH < 106 solar masses (…
Macro and micro structures of pebble-made cometary nuclei reconciled by seasonal evolution
Longobardo, Andrea; Mottola, Stefano; Kappel, David +17 more
Comets evolve due to sublimation of ices embedded inside porous dust, triggering dust emission (that is, erosion) followed by mass loss, mass redistribution and surface modifications. Surface changes were revealed by the Deep Impact and Stardust NExT missions for comet 9P/Tempel 1 (ref. 1), and a full inventory of the processes modifyin…
Discovery of post-mass-transfer helium-burning red giants using asteroseismology
Wu, Yaqian; Bi, Shaolan; Li, Yaguang +14 more
A star expands to become a red giant when it has fused all the hydrogen in its core into helium. If the star is in a binary system, its envelope can overflow onto its companion or be ejected into space, leaving a hot core and potentially forming a subdwarf B star1-3. However, most red giants that have partially transferred envelopes in …
A likely flyby of binary protostar Z CMa caught in action
Henning, Thomas; Dong, Ruobing; Pyo, Tae-Soo +16 more
Close encounters between young stellar objects in star-forming clusters are expected to markedly perturb circumstellar disks. Such events are witnessed in numerical simulations of star formation1-3, but few direct observations of ongoing encounters have been made. Here we report sub-0.1″-resolution Atacama Large Millimeter/Submillimeter…
Chemical and stellar properties of star-forming dwarf galaxies
Tosi, Monica; Annibali, Francesca
Dwarf galaxies are the least massive, most abundant and most widely distributed type of galaxy. Hence, they are key to testing theories of galaxy and Universe evolution. Dwarf galaxies sufficiently close to have their gas and stellar components studied in detail are of particular interest, because their properties and evolution can be inferred wit…
The messy death of a multiple star system and the resulting planetary nebula as observed by JWST
Ventura, Paolo; Amram, Philippe; Mendes de Oliveira, Claudia +66 more
Planetary nebulae—the ejected envelopes of red giant stars—provide us with a history of the last, mass-losing phases of 90% of stars initially more massive than the Sun. Here we analyse images of the planetary nebula NGC 3132 from the James Webb Space Telescope (JWST) Early Release Observations. A structured, extended hydrogen halo surrounding an …