Dr Andrew Robertson's Outputs (38)

A high-resolution cosmological simulation of a strong gravitational lens (2021)
Journal Article
Richings, J., Frenk, C., Jenkins, A., Robertson, A., & Schaller, M. (2021). A high-resolution cosmological simulation of a strong gravitational lens. Monthly Notices of the Royal Astronomical Society, 501(3), 4657-4668. https://doi.org/10.1093/mnras/staa4013

We present a cosmological hydrodynamical simulation of a 1013 M⊙ galaxy group and its environment (out to 10 times the virial radius) carried out using the EAGLE model of galaxy formation. Exploiting a novel technique to increase the resolution of th... Read More about A high-resolution cosmological simulation of a strong gravitational lens.

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.-I., 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.

Local group star formation in warm and self-interacting dark matter cosmologies (2020)
Journal Article
Lovell, M., Hellwing, W., Ludlow, A., Zavala, J., Robertson, A., Fattahi, A., Frenk, C., & Hardwick, J. (2020). Local group star formation in warm and self-interacting dark matter cosmologies. Monthly Notices of the Royal Astronomical Society, 498(1), 702-717. https://doi.org/10.1093/mnras/staa2525

The nature of the dark matter can affect the collapse time of dark matter haloes, and can therefore be imprinted in observables such as the stellar population ages and star formation histories of dwarf galaxies. In this paper, we use high-resolution... Read More about Local group star formation in warm and self-interacting dark matter cosmologies.

To β or not to β: can higher-order Jeans analysis break the mass–anisotropy degeneracy in simulated dwarfs? (2020)
Journal Article
Genina, A., Read, J., Frenk, C., Cole, S., Benítez-Llambay, A., Ludlow, A., Navarro, J., Oman, K., & Robertson, A. (2020). To β or not to β: can higher-order Jeans analysis break the mass–anisotropy degeneracy in simulated dwarfs?. Monthly Notices of the Royal Astronomical Society, 498(1), 144-163. https://doi.org/10.1093/mnras/staa2352

We test a non-parametric higher-order Jeans analysis method, GRAVSPHERE, on 32 simulated dwarf galaxies comparable to classical Local Group dwarfs like Fornax. The galaxies are selected from the APOSTLE suite of cosmological hydrodynamics simulations... Read More about To β or not to β: can higher-order Jeans analysis break the mass–anisotropy degeneracy in simulated dwarfs?.

Exploring extensions to the standard cosmological model and the impact of baryons on small scales (2020)
Journal Article
Stafford, S. G., Brown, S. T., McCarthy, I. G., Font, A. S., Robertson, A., & Poole-McKenzie, R. (2020). Exploring extensions to the standard cosmological model and the impact of baryons on small scales. Monthly Notices of the Royal Astronomical Society, 497(3), 3809-3829. https://doi.org/10.1093/mnras/staa2059

It has been claimed that the standard model of cosmology (ΛCDM) cannot easily account for a number of observations on relatively small scales, motivating extensions to the standard model. Here, we introduce a new suite of cosmological simulations tha... Read More about Exploring extensions to the standard cosmological model and the impact of baryons on small scales.

Mapping dark matter and finding filaments: calibration of lensing analysis techniques on simulated data (2020)
Journal Article
Tam, S.-I., 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.

Baryonic clues to the puzzling diversity of dwarf galaxy rotation curves (2020)
Journal Article
Santos-Santos, I. M., Navarro, J. F., Robertson, A., Benítez-Llambay, A., Oman, K. A., Lovell, M. R., Frenk, C. S., Ludlow, A. D., Fattahi, A., & Ritz, A. (2020). Baryonic clues to the puzzling diversity of dwarf galaxy rotation curves. Monthly Notices of the Royal Astronomical Society, 495(1), 58-77. https://doi.org/10.1093/mnras/staa1072

We use a compilation of disc galaxy rotation curves to assess the role of the luminous component (‘baryons’) in the rotation curve diversity problem. As in earlier work, we find that rotation curve shape correlates with baryonic surface density: high... Read More about Baryonic clues to the puzzling diversity of dwarf galaxy rotation curves.

The BUFFALO HST Survey (2020)
Journal Article
Steinhardt, C. L., Jauzac, M., Acebron, A., Atek, H., Capak, P., Davidzon, I., Eckert, D., Harvey, D., Koekemoer, A. M., Lagos, C. D., Mahler, G., Montes, M., Niemiec, A., Nonino, M., Oesch, P., Richard, J., Rodney, S. A., Schaller, M., Sharon, K., Strolger, L.-G., …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.

Subhalo destruction in the Apostle and Auriga simulations (2019)
Journal Article
Richings, J., Frenk, C., Jenkins, A., Robertson, A., Fattahi, A., Grand, R. J., Navarro, J., Pakmor, R., Gomez, F. A., Marinacci, F., & Oman, K. (2020). Subhalo destruction in the Apostle and Auriga simulations. Monthly Notices of the Royal Astronomical Society, 492(4), 5780-5793. https://doi.org/10.1093/mnras/stz3448

N-body simulations make unambiguous predictions for the abundance of substructures within dark matter halos. However, the inclusion of baryons in the simulations changes the picture because processes associated with the presence of a large galaxy in... Read More about Subhalo destruction in the Apostle and Auriga simulations.

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.

The impact of cored density profiles on the observable quantities of dwarf spheroidal galaxies (2018)
Journal Article
Harvey, D., Revaz, Y., Robertson, A., & Hausammann, L. (2018). The impact of cored density profiles on the observable quantities of dwarf spheroidal galaxies. Monthly Notices of the Royal Astronomical Society: Letters, 481(1), L89-L93. https://doi.org/10.1093/mnrasl/sly159

We modify the chemo-dynamical code GEAR to simulate the impact of self-interacting dark matter (SIDM) on the observable quantities of 19 low-mass dwarf galaxies with a variety star-forming properties. We employ a relatively high, velocity independent... Read More about The impact of cored density profiles on the observable quantities of dwarf spheroidal galaxies.

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.