Search Publications
DYNESTY: a dynamic nested sampling package for estimating Bayesian posteriors and evidences
Speagle, Joshua S.
We present DYNESTY, a public, open-source, PYTHON package to estimate Bayesian posteriors and evidences (marginal likelihoods) using the dynamic nested sampling methods developed by Higson et al. By adaptively allocating samples based on posterior structure, dynamic nested sampling has the benefits of Markov chain Monte Carlo (MCMC) algorithms tha…
H0LiCOW - XIII. A 2.4 per cent measurement of H0 from lensed quasars: 5.3σ tension between early- and late-Universe probes
Treu, Tommaso; Marshall, Philip J.; Sonnenfeld, Alessandro +23 more
We present a measurement of the Hubble constant (H0) and other cosmological parameters from a joint analysis of six gravitationally lensed quasars with measured time delays. All lenses except the first are analysed blindly with respect to the cosmological parameters. In a flat Λ cold dark matter (ΛCDM) cosmology, we find $H_{0} = 73.3_{…
Unresolved stellar companions with Gaia DR2 astrometry
Everall, Andrew; Brown, Anthony G. A.; Belokurov, Vasily +9 more
For stars with unresolved companions, motions of the centre of light and that of mass decouple, causing a single-source astrometric model to perform poorly. We show that such stars can be easily detected with the reduced χ2 statistic, or renormalized unit weight error (RUWE), provided as part of Gaia DR2. We convert RUWE into the amplit…
The milky way total mass profile as inferred from Gaia DR2
Grand, Robert J. J.; Gómez, Facundo A.; Fattahi, Azadeh +7 more
We determine the Milky Way (MW) mass profile inferred from fitting physically motivated models to the Gaia DR2 Galactic rotation curve and other data. Using various hydrodynamical simulations of MW-mass haloes, we show that the presence of baryons induces a contraction of the dark matter (DM) distribution in the inner regions, r ≲ 20 kpc. We provi…
The biggest splash
Grand, Robert J. J.; Fattahi, Azadeh; Belokurov, Vasily +4 more
Using a large sample of bright nearby stars with accurate Gaia Data Release 2 astrometry and auxiliary spectroscopy we map out the properties of the principle Galactic components such as the 'thin' and 'thick' discs and the halo. We confirm previous claims that in the Solar neighbourhood, there exists a large population of metal-rich ([Fe/H] > …
The lifecycle of molecular clouds in nearby star-forming disc galaxies
Henshaw, Jonathan D.; Kruijssen, J. M. Diederik; Longmore, Steven N. +29 more
It remains a major challenge to derive a theory of cloud-scale (≲100 pc) star formation and feedback, describing how galaxies convert gas into stars as a function of the galactic environment. Progress has been hampered by a lack of robust empirical constraints on the giant molecular cloud (GMC) lifecycle. We address this problem by systematically …
An ALMA survey of the SCUBA-2 CLS UDS field: physical properties of 707 sub-millimetre galaxies
Thomson, A. P.; Ivison, R. J.; Scott, D. +27 more
We analyse the physical properties of a large, homogeneously selected sample of ALMA-located sub-millimetre galaxies (SMGs). This survey, AS2UDS, identified 707 SMGs across the ∼1 deg2 field, including ∼17 per cent, which are undetected at K ≳ 25.7 mag. We interpret their ultraviolet-to-radio data using magphys and determine a median re…
Kraken reveals itself - the merger history of the Milky Way reconstructed with the E-MOSAICS simulations
Kruijssen, J. M. Diederik; Chevance, Mélanie; Bonaca, Ana +6 more
Globular clusters (GCs) formed when the Milky Way experienced a phase of rapid assembly. We use the wealth of information contained in the Galactic GC population to quantify the properties of the satellite galaxies from which the Milky Way assembled. To achieve this, we train an artificial neural network on the E-MOSAICS cosmological simulations o…
X-CIGALE: Fitting AGN/galaxy SEDs from X-ray to infrared
Ciesla, L.; Papovich, C.; Brandt, W. N. +6 more
Code Investigating GALaxy Emission (CIGALE) is a powerful multiwavelength spectral energy distribution (SED) fitting code for extragalactic studies. However, the current version of CIGALE is not able to fit X-ray data, which often provide unique insights into active galactic nucleus (AGN) intrinsic power. We develop a new X-ray module for CIGALE, …
A cosmic UV/X-ray background model update
Faucher-Giguère, Claude-André
We present an updated model of the cosmic ionizing background from the UV to the X-rays. Relative to our previous model, the new model provides a better match to a large number of up-to-date empirical constraints, including: (1) new galaxy and AGN luminosity functions; (2) stellar spectra including binary stars; (3) obscured and unobscured AGN; (4…