PyAutoGalaxy: Open-Source Multiwavelength Galaxy Structure & Morphology (2023)
Journal Article
Nightingale, J. W., Amvrosiadis, A., Hayes, R. G., He, Q., Etherington, A., Cao, X., …Robertson, A. (2023). PyAutoGalaxy: Open-Source Multiwavelength Galaxy Structure & Morphology. The Journal of Open Source Software, 8(81), Article 4475. https://doi.org/10.21105/joss.04475

Nearly a century ago, Edwin Hubble famously classified galaxies into three distinct groups: ellipticals, spirals and irregulars (Hubble, 1926). Today, by analysing millions of galaxies with advanced image processing techniques Astronomers have expand... Read More about PyAutoGalaxy: Open-Source Multiwavelength Galaxy Structure & Morphology.

The effects of self-interacting dark matter on the stripping of galaxies that fall into clusters (2022)
Journal Article
Sirks, E. L., Oman, K. A., Robertson, A., Massey, R., & Frenk, C. (2022). The effects of self-interacting dark matter on the stripping of galaxies that fall into clusters. Monthly Notices of the Royal Astronomical Society, 511(4), 5927-5935. https://doi.org/10.1093/mnras/stac406

We use the Cluster-EAGLE (C-EAGLE) hydrodynamical simulations to investigate the effects of self-interacting dark matter (SIDM) on galaxies as they fall into clusters. We find that SIDM galaxies follow similar orbits to their cold dark matter (CDM) c... Read More about The effects of self-interacting dark matter on the stripping of galaxies that fall into clusters.

Systematic Errors Induced by the Elliptical Power-law model in Galaxy–Galaxy Strong Lens Modeling (2022)
Journal Article
Cao, X., Li, R., Nightingale, J., Massey, R., Robertson, A., Frenk, C. S., …Zhu, K. (2022). Systematic Errors Induced by the Elliptical Power-law model in Galaxy–Galaxy Strong Lens Modeling. Research in Astronomy and Astrophysics, 22(2), https://doi.org/10.1088/1674-4527/ac3f2b

The elliptical power-law (EPL) model of the mass in a galaxy is widely used in strong gravitational lensing analyses. However, the distribution of mass in real galaxies is more complex. We quantify the biases due to this model mismatch by simulating... Read More about Systematic Errors Induced by the Elliptical Power-law model in Galaxy–Galaxy Strong Lens Modeling.

A forward-modelling method to infer the dark matter particle mass from strong gravitational lenses (2022)
Journal Article
He, Q., Robertson, A., Nightingale, J., Cole, S., Frenk, C. S., Massey, R., …Etherington, A. (2022). A forward-modelling method to infer the dark matter particle mass from strong gravitational lenses. Monthly Notices of the Royal Astronomical Society, 511(2), 3046-3062. https://doi.org/10.1093/mnras/stac191

A fundamental prediction of the cold dark matter (CDM) model of structure formation is the existence of a vast population of dark matter haloes extending to subsolar masses. By contrast, other dark matter models, such as a warm thermal relic (WDM), p... Read More about A forward-modelling method to infer the dark matter particle mass from strong gravitational lenses.

Halo concentration strengthens dark matter constraints in galaxy-galaxy strong lensing analyses (2021)
Journal Article
Amorisco, N. C., Nightingale, J., He, Q., Amvrosiadis, A., Cao, X., Cole, S., …Robertson, A. (2022). Halo concentration strengthens dark matter constraints in galaxy-galaxy strong lensing analyses. Monthly Notices of the Royal Astronomical Society, 510, 2464-2479. https://doi.org/10.1093/mnras/stab3527

A defining prediction of the cold dark matter cosmological model is the existence of a very large population of low-mass haloes. This population is absent in models in which the dark matter particle is warm (WDM). These alternatives can, in principle... Read More about Halo concentration strengthens dark matter constraints in galaxy-galaxy strong lensing analyses.

PyAutoLens: Open-Source Strong Gravitational Lensing (2021)
Journal Article
Nightingale, J., Hayes, R., Kelly, A., Amvrosiadis, A., Etherington, A., He, Q., …Robertson, A. (2021). PyAutoLens: Open-Source Strong Gravitational Lensing. The Journal of Open Source Software, 6(58), Article 2825. https://doi.org/10.21105/joss.02825

Strong gravitational lensing, which can make a background source galaxy appears multiple times due to its light rays being deflected by the mass of one or more foreground lens galaxies, provides astronomers with a powerful tool to study dark matter,... Read More about PyAutoLens: Open-Source Strong Gravitational Lensing.

The surprising accuracy of isothermal Jeans modelling of self-interacting dark matter density profiles (2020)
Journal Article
Robertson, A., Massey, R., Eke, V., Schaye, J., & Theuns, T. (2021). The surprising accuracy of isothermal Jeans modelling of self-interacting dark matter density profiles. Monthly Notices of the Royal Astronomical Society, 501(3), 4610-5634. https://doi.org/10.1093/mnras/staa3954

Recent claims of observational evidence for self-interacting dark matter (SIDM) have relied on a semi-analytic method for predicting the density profiles of galaxies and galaxy clusters containing SIDM. We present a thorough description of this metho... Read More about The surprising accuracy of isothermal Jeans modelling of self-interacting dark matter density profiles.

Reconciling galaxy cluster shapes, measured by theorists vs observers (2020)
Journal Article
Harvey, D., Robertson, A., Tam, S., Jauzac, M., Massey, R., Rhodes, J., & McCarthy, I. G. (2021). Reconciling galaxy cluster shapes, measured by theorists vs observers. Monthly Notices of the Royal Astronomical Society, 500(2), 2627-2644. https://doi.org/10.1093/mnras/staa3193

If properly calibrated, the shapes of galaxy clusters can be used to investigate many physical processes: from feedback and quenching of star formation, to the nature of dark matter. Theorists frequently measure shapes using moments of inertia of sim... Read More about Reconciling galaxy cluster shapes, measured by theorists vs observers.

Mapping dark matter and finding filaments: calibration of lensing analysis techniques on simulated data (2020)
Journal Article
Tam, S., Massey, R., Jauzac, M., & Robertson, A. (2020). Mapping dark matter and finding filaments: calibration of lensing analysis techniques on simulated data. Monthly Notices of the Royal Astronomical Society, 496(3), 3973-3990. https://doi.org/10.1093/mnras/staa1756

We quantify the performance of mass mapping techniques on mock imaging and gravitational lensing data of galaxy clusters. The optimum method depends upon the scientific goal. We assess measurements of clusters’ radial density profiles, departures fro... Read More about Mapping dark matter and finding filaments: calibration of lensing analysis techniques on simulated data.

What does strong gravitational lensing? The mass and redshift distribution of high-magnification lenses (2020)
Journal Article
Robertson, A., Smith, G. P., Massey, R., Eke, V., Jauzac, M., Bianconi, M., & Ryczanowski, D. (2020). What does strong gravitational lensing? The mass and redshift distribution of high-magnification lenses. Monthly Notices of the Royal Astronomical Society, 495(4), 3727-3739. https://doi.org/10.1093/mnras/staa1429

Many distant objects can only be detected, or become more scientifically valuable, if they have been highly magnified by strong gravitational lensing. We use eagle and bahamas, two recent cosmological hydrodynamical simulations, to predict the probab... Read More about What does strong gravitational lensing? The mass and redshift distribution of high-magnification lenses.

On building a cluster watch-list for identifying strongly lensed supernovae, gravitational waves and kilonovae (2020)
Journal Article
Ryczanowski, D., Smith, G. P., Bianconi, M., Massey, R., Robertson, A., & Jauzac, M. (2020). On building a cluster watch-list for identifying strongly lensed supernovae, gravitational waves and kilonovae. Monthly Notices of the Royal Astronomical Society, 495(2), 1666-1671. https://doi.org/10.1093/mnras/staa1274

Motivated by discovering strongly-lensed supernovae, gravitational waves, and kilonovae in the 2020s, we investigate whether to build a watch-list of clusters based on observed cluster properties (i.e. lens-plane selection) or on the detectability of... Read More about On building a cluster watch-list for identifying strongly lensed supernovae, gravitational waves and kilonovae.

Understanding the large inferred Einstein radii of observed low-mass galaxy clusters (2020)
Journal Article
Robertson, A., Massey, R., & Eke, V. (2020). Understanding the large inferred Einstein radii of observed low-mass galaxy clusters. Monthly Notices of the Royal Astronomical Society, 494(4), 4706-4712. https://doi.org/10.1093/mnras/staa1076

We assess a claim that observed galaxy clusters with mass ∼1014M⊙ are more centrally concentrated than predicted in lambda cold dark matter (ΛCDM). We generate mock strong gravitational lensing observations, taking the lenses from a cosmological hydr... Read More about Understanding the large inferred Einstein radii of observed low-mass galaxy clusters.

The BUFFALO HST Survey (2020)
Journal Article
Steinhardt, C. L., Jauzac, M., Acebron, A., Atek, H., Capak, P., Davidzon, I., …Zitrin, A. (2020). The BUFFALO HST Survey. Astrophysical Journal Supplement, 247(2), Article 64. https://doi.org/10.3847/1538-4365/ab75ed

The Beyond Ultra-deep Frontier Fields and Legacy Observations (BUFFALO) is a 101 orbit + 101 parallel Cycle 25 Hubble Space Telescope (HST) Treasury program taking data from 2018 to 2020. BUFFALO will expand existing coverage of the Hubble Frontier F... Read More about The BUFFALO HST Survey.

Observable tests of self-interacting dark matter in galaxy clusters: BCG wobbles in a constant density core (2019)
Journal Article
Harvey, D., Robertson, A., Massey, R., & McCarthy, I. G. (2019). Observable tests of self-interacting dark matter in galaxy clusters: BCG wobbles in a constant density core. Monthly Notices of the Royal Astronomical Society, 488(2), 1572-1579. https://doi.org/10.1093/mnras/stz1816

Models of cold dark matter (CDM) predict that the distribution of dark matter in galaxy clusters should be cuspy, centrally concentrated. Constant density cores would be strong evidence for beyond CDM physics, such as self-interacting dark matter (SI... Read More about Observable tests of self-interacting dark matter in galaxy clusters: BCG wobbles in a constant density core.

Self-interacting dark matter scattering rates through cosmic time (2015)
Journal Article
Robertson, A., Massey, R., Eke, V., & Bower, R. (2015). Self-interacting dark matter scattering rates through cosmic time. Monthly Notices of the Royal Astronomical Society, 453(3), 2267-2276. https://doi.org/10.1093/mnras/stv1805

We estimate the rate of dark matter scattering in collapsed structures throughout the history of the Universe. If the scattering cross-section is velocity independent, then the canonical picture is correct that scatterings occur mainly at late times.... Read More about Self-interacting dark matter scattering rates through cosmic time.

The offsets between galaxies and their dark matter in Λ cold dark matter (2015)
Journal Article
Schaller, M., Robertson, A., Massey, R., Bower, R. G., & Eke, V. R. (2015). The offsets between galaxies and their dark matter in Λ cold dark matter. Monthly Notices of the Royal Astronomical Society: Letters, 453(1), L58-L62. https://doi.org/10.1093/mnrasl/slv104

We use the ‘Evolution and Assembly of GaLaxies and their Environments’ (EAGLE) suite of hydrodynamical cosmological simulations to measure offsets between the centres of stellar and dark matter components of galaxies. We find that the vast majority (... Read More about The offsets between galaxies and their dark matter in Λ cold dark matter.

The behaviour of dark matter associated with four bright cluster galaxies in the 10 kpc core of Abell 3827 (2015)
Journal Article
Massey, R., Williams, L., Smit, R., Swinbank, M., Kitching, D., Harvey, D., …Tittley, E. (2015). The behaviour of dark matter associated with four bright cluster galaxies in the 10 kpc core of Abell 3827. Monthly Notices of the Royal Astronomical Society, 449(4), 3393-3406. https://doi.org/10.1093/mnras/stv467

Galaxy cluster Abell 3827 hosts the stellar remnants of four almost equally bright elliptical galaxies within a core of radius 10 kpc. Such corrugation of the stellar distribution is very rare, and suggests recent formation by several simultaneous me... Read More about The behaviour of dark matter associated with four bright cluster galaxies in the 10 kpc core of Abell 3827.