Search Publications
A small and vigorous black hole in the early Universe
Charlot, Stéphane; Chevallard, Jacopo; Maseda, Michael V. +36 more
Several theories have been proposed to describe the formation of black hole seeds in the early Universe and to explain the emergence of very massive black holes observed in the first thousand million years after the Big Bang1-3. Models consider different seeding and accretion scenarios4-7, which require the detection and char…
Heavy-element production in a compact object merger observed by JWST
Fruchter, Andrew S.; Barclay, Thomas; Izzo, Luca +82 more
The mergers of binary compact objects such as neutron stars and black holes are of central interest to several areas of astrophysics, including as the progenitors of gamma-ray bursts (GRBs)1, sources of high-frequency gravitational waves (GWs)2 and likely production sites for heavy-element nucleosynthesis by means of rapid ne…
Spectroscopic confirmation of two luminous galaxies at a redshift of 14
Pérez-González, Pablo G.; Charlot, Stéphane; Chevallard, Jacopo +42 more
The first observations of the James Webb Space Telescope (JWST) have revolutionized our understanding of the Universe by identifying galaxies at redshift z ≈ 13 (refs. 1, 2–3). In addition, the discovery of many luminous galaxies at Cosmic Dawn (z > 10) has suggested that galaxies developed rapidly, in apparent tension with many stan…
A high black-hole-to-host mass ratio in a lensed AGN in the early Universe
Charlot, Stéphane; Glazebrook, Karl; Labbé, Ivo +35 more
Early JWST observations have uncovered a population of red sources that might represent a previously overlooked phase of supermassive black hole growth1-3. One of the most intriguing examples is an extremely red, point-like object that was found to be triply imaged by the strong lensing cluster Abell 2744 (ref. 4). Here we pr…
Most of the photons that reionized the Universe came from dwarf galaxies
Papovich, Casey; Maseda, Michael V.; Muzzin, Adam +30 more
The identification of sources driving cosmic reionization, a major phase transition from neutral hydrogen to ionized plasma around 600-800 Myr after the Big Bang1-3, has been a matter of debate4. Some models suggest that high ionizing emissivity and escape fractions (fesc) from quasars support their role in driving…
A recently quenched galaxy 700 million years after the Big Bang
Chevallard, Jacopo; Maseda, Michael V.; Carniani, Stefano +42 more
Local and low-redshift (z < 3) galaxies are known to broadly follow a bimodal distribution: actively star-forming galaxies with relatively stable star-formation rates and passive systems. These two populations are connected by galaxies in relatively slow transition. By contrast, theory predicts that star formation was stochastic at early cosmic…
Bound star clusters observed in a lensed galaxy 460 Myr after the Big Bang
Mahler, Guillaume; Fujimoto, Seiji; Inoue, Akio K. +25 more
The Cosmic Gems arc is among the brightest and highly magnified galaxies observed at redshift z ≈ 10.2 (ref. 1). However, it is an intrinsically ultraviolet faint galaxy, in the range of those now thought to drive the reionization of the Universe2–4. Hitherto the smallest features resolved in a galaxy at a comparable redshift…
A lanthanide-rich kilonova in the aftermath of a long gamma-ray burst
Kilpatrick, Charles D.; Lee, Chung-Uk; Im, Myungshin +24 more
Observationally, kilonovae are astrophysical transients powered by the radioactive decay of nuclei heavier than iron, thought to be synthesized in the merger of two compact objects1-4. Over the first few days, the kilonova evolution is dominated by a large number of radioactive isotopes contributing to the heating rate2,5. On…
Accelerated formation of ultra-massive galaxies in the first billion years
Dickinson, Mark; Illingworth, Garth D.; Labbé, Ivo +35 more
Recent James Webb Space Telescope (JWST) observations have revealed an unexpected abundance of massive-galaxy candidates in the early Universe, extending further in redshift and to lower luminosity than what had previously been found by submillimetre surveys1–6. These JWST candidates have been interpreted as challenging the Λ cold dark-…
A massive galaxy that formed its stars at z ≈ 11
Papovich, Casey; Kacprzak, Glenn G.; Glazebrook, Karl +15 more
The formation of galaxies by gradual hierarchical co-assembly of baryons and cold dark matter halos is a fundamental paradigm underpinning modern astrophysics1,2 and predicts a strong decline in the number of massive galaxies at early cosmic times3-5. Extremely massive quiescent galaxies (stellar masses of more than 1011…