Gabriel Brammer

Feb 14, 2024 | nature.com | Karl Glazebrook |Themiya Nanayakkara |Claudia Lagos |Gabriel Brammer |Ivo Labbe |Pascal Oesch | +4 more

AbstractThe formation of galaxies by gradual hierarchical co-assembly of baryons and cold dark matter halos is a fundamental paradigm underpinning modern astrophysics[1, 2] and predicts a strong decline in the number of massive galaxies at early cosmic times[3–5].

Feb 14, 2024 | nature.com | Lukas J. Furtak |Ivo Labbe |Adi Zitrin |Anna de Graaff |Rachel Bezanson |Gabriel Brammer | +14 more

AbstractEarly JWST observations have uncovered a new 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 (SL) cluster Abell 27444. Here we present deep JWST/NIRSpec observations of this object, Abell2744-QSO1.

Oct 25, 2023 | nature.com | Andrew J. Levan |Benjamin P. Gompertz |Eric Burns |Luca Izzo |Gavin Lamb |Daniele B. Malesani | +43 more

AbstractThe 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 (GW)2 and likely production sites for heavy element nucleosynthesis via rapid neutron capture (the r-process)3. Here we present observations of the exceptionally bright gamma-ray burst GRB 230307A.

Oct 19, 2023 | nature.com | Pieter van Dokkum |Gabriel Brammer |Bingjie Wang

AbstractOne 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 mass added later through minor mergers.