Search Publications
The UV continuum slopes of early star-forming galaxies in JADES
Chevallard, Jacopo; Carniani, Stefano; Bunker, Andrew J. +22 more
The power-law slope of the rest-ultraviolet (UV) continuum (fλ ∝ λβ) is a key metric of early star-forming galaxies, providing one of our only windows into the stellar populations and physical conditions of z ≳ 10 galaxies. Expanding upon previous studies with limited sample sizes, we leverage deep imaging from the JWST Advan…
The dark matter profile of the Milky Way inferred from its circular velocity curve
Frebel, Anna; Eilers, Anna-Christina; Necib, Lina +1 more
In this paper, we construct the circular velocity curve of the Milky Way out to ~30 kpc, providing an updated model of the dark matter density profile. We derive precise parallaxes for 120 309 stars with a data-driven model, using APOGEE DR17 spectra combined with GaiaDR3, 2MASS, and WISE photometry. At outer galactic radii up to 30 kpc, we find a…
Exploring the nature of UV-bright z ≳ 10 galaxies detected by JWST: star formation, black hole accretion, or a non-universal IMF?
Graziani, Luca; Schneider, Raffaella; Chon, Sunmyon +4 more
We use the Cosmic Archaeology Tool (CAT) semi-analytical model to explore the contribution of Population (Pop) III/II stars and active galactic nuclei (AGNs) to the galaxy ultraviolet (UV) luminosity function (LF) evolution at 4 ≤ z ≤ 20. We compare in particular with recent JWST data in order to explore the apparent tension between observations a…
Reionization after JWST: a photon budget crisis?
Chisholm, John; Mason, Charlotte; Furlanetto, Steven R. +2 more
New JWST observations are revealing the first galaxies to be prolific producers of ionizing photons, which we argue gives rise to a tension between different probes of reionization. Over the last two decades, a consensus has emerged where star-forming galaxies are able to generate enough photons to drive reionization, given reasonable values for t…
GA-NIFS: JWST discovers an offset AGN 740 million years after the big bang
Pérez-González, Pablo G.; Grogin, Norman A.; Charlot, Stéphane +24 more
A surprising finding of recent studies is the large number of Active Galactic Nuclei (AGN) associated with moderately massive black holes (
Extreme emission line galaxies detected in JADES JWST/NIRSpec - I. Inferred galaxy properties
Charlot, Stéphane; Chevallard, Jacopo; Maseda, Michael V. +33 more
Extreme emission line galaxies (EELGs) exhibit large equivalent widths (EW) in their rest-optical emission lines ([O III]
The ultraviolet continuum slopes of high-redshift galaxies: evidence for the emergence of dust-free stellar populations at z > 10
Bowler, R. A. A.; Cullen, F.; McLure, R. J. +11 more
We present an analysis of the ultraviolet (UV) continuum slopes (β) for a sample of 172 galaxy candidates at 8 < zphot < 16 selected from a combination of JWST NIRCam imaging and COSMOS/UltraVISTA ground-based near-infrared imaging. Focusing primarily on a new sample of 121 galaxies at ⟨z⟩ ≃ 11 selected from ≃ 320 arcmin2
In-situ versus accreted Milky Way globular clusters: a new classification method and implications for cluster formation
Belokurov, Vasily; Kravtsov, Andrey
We present a new scheme for the classification of the in-situ and accreted globular clusters (GCs). The scheme uses total energy E and z-component of the orbital angular momentum and is calibrated using the [Al/Fe] abundance ratio. We demonstrate that this classification results in two GC populations with distinct spatial, kinematic, and chemical …
There is no place like home - finding birth radii of stars in the Milky Way
Steinmetz, Matthias; Buck, Tobias; Freeman, Ken C. +6 more
Stars move away from their birthplaces over time via a process known as radial migration, which blurs chemo-kinematic relations used for reconstructing the Milky Way (MW) formation history. To understand the true time evolution of the MW, one needs to take into account the effects of this process. We show that stellar birth radii can be derived di…
The 40 pc sample of white dwarfs from Gaia
Gänsicke, B. T.; Tremblay, P. -E.; Hollands, M. A. +14 more
We present a comprehensive overview of a volume-complete sample of white dwarfs located within 40 pc of the Sun, a significant proportion of which were detected in Gaia Data Release 3 (DR3). Our DR3 sample contains 1076 spectroscopically confirmed white dwarfs, with just five candidates within the volume remaining unconfirmed (> 99 per cent spe…