Search Publications
Gravitational imaging through a triple source plane lens: revisiting the ΛCDM-defying dark subhalo in SDSSJ0946+1006
Collett, Thomas E.; Smith, Russell J.; Turner, Hannah C. +2 more
The ΛCDM paradigm successfully explains the large-scale structure of the Universe, but is less well constrained on subgalactic scales. Gravitational lens modelling has been used to measure the imprints of dark substructures on lensed arcs, testing the small-scale predictions of ΛCDM. However, the methods required for these tests are subject to deg…
The NIRVANDELS survey: the stellar and gas-phase mass-metallicity relations of star-forming galaxies at z = 3.5
Cullen, F.; McLure, R. J.; Dunlop, J. S. +18 more
We present determinations of the gas-phase and stellar metallicities of a sample of 65 star-forming galaxies at $z \simeq 3.5$ using rest-frame far-ultraviolet (FUV) spectroscopy from the VANDELS survey in combination with follow-up rest-frame optical spectroscopy from VLT/KMOS and Keck/MOSFIRE. We infer gas-phase oxygen abundances ($Z_{\mathrm{g}…
Reaching for the stars - JWST/NIRSpec spectroscopy of a lensed star candidate at z = 4.76
Ravindranath, Swara; Wilkins, Stephen M.; Mahler, Guillaume +31 more
We present JWST/NIRSpec observations of a highly magnified star candidate at a photometric redshift of zphot ≃ 4.8, previously detected in JWST/NIRCam imaging of the strong lensing (SL) cluster MACS J0647+7015 (z = 0.591). The spectroscopic observation allows us to precisely measure the redshift of the host arc at zspec = 4.7…
To be, or not to be: Balmer breaks in high-z galaxies with JWST
Coe, Dan; Bradley, Larry D.; Zackrisson, Erik +7 more
Standard models of structure formation allow us to predict the cosmic timescales relevant for the onset of star formation and the assembly history of galaxies at high redshifts (z > 10). The strength of the Balmer break represents a well-known diagnostic of the age and star formation history of galaxies, which enables us to compare observations…
Taking the Milky Way for a spin: disc formation in the ARTEMIS simulations
Belokurov, Vasily; Dillamore, Adam M.; Font, Andreea S. +1 more
We investigate the formation (spin-up) of galactic discs in the ARTEMIS simulations of Milky Way (MW)-mass galaxies. In almost all galaxies, discs spin up at higher [Fe/H] than the MW. Those galaxies that contain an analogue of the Gaia Sausage-Enceladus (GSE) spin up at a lower average metallicity than those without. We identify six galaxies with…
Supermassive black hole mass in the massive elliptical galaxy M87 from integral-field stellar dynamics using OASIS and MUSE with adaptive optics: assessing systematic uncertainties
Cappellari, Michele; Hartke, Johanna; Simon, David A.
The massive elliptical galaxy M87 has been the subject of several supermassive black hole mass measurements from stellar dynamics, gas dynamics, and recently the black hole shadow by the Event Horizon Telescope. This uniquely positions M87 as a benchmark for alternative black hole mass determination methods. Here, we use stellar kinematics extract…
Surviving the waves: evidence for a dark matter cusp in the tidally disrupting Small Magellanic Cloud
Massana, Pol; Erkal, Denis; De Leo, Michele +3 more
We use spectroscopic data for
EDGE: The direct link between mass growth history and the extended stellar haloes of the faintest dwarf galaxies
Orkney, Matthew D. A.; Pontzen, Andrew; Noël, Noelia E. D. +9 more
Ultra-faint dwarf galaxies (UFDs) are commonly found in close proximity to the Milky Way and other massive spiral galaxies. As such, their projected stellar ellipticity and extended light distributions are often thought to owe to tidal forces. In this paper, we study the projected stellar ellipticities and faint stellar outskirts of tidally isolat…
The cosmic dipole in the Quaia sample of quasars: a Bayesian analysis
Lewis, Geraint F.; Mittal, Vasudev; Oayda, Oliver T.
We present a Bayesian analysis of the Quaia sample of 1.3 million quasars as a test of the cosmological principle. This principle postulates that the Universe is homogeneous and isotropic on sufficiently large scales, forming the basis of prevailing cosmological models. However, recent analyses of quasar samples have found a matter dipole inconsis…
The Merian survey: design, construction, and characterization of a filter set optimized to find dwarf galaxies and measure their dark matter halo properties with weak lensing
Johnson, Sean D.; Cai, Zheng; Lin, Xiaojing +28 more
The Merian survey is mapping ~ 850 deg2 of the Hyper Suprime-Cam Strategic Survey Program (HSC-SSP) wide layer with two medium-band filters on the 4-m Victor M. Blanco telescope at the Cerro Tololo Inter-American Observatory, with the goal of carrying the first high signal-to-noise (S/N) measurements of weak gravitational lensing around…