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Dr Andrew Robertson's Outputs (38)

SuperBIT Superpressure Flight Instrument Overview and Performance: Near-diffraction-limited Astronomical Imaging from the Stratosphere (2024)
Journal Article
Gill, A. S., Benton, S. J., Damaren, C. J., Everett, S. W., Fraisse, A. A., Hartley, J. W., Harvey, D., Holder, B., Huff, E. M., Jones, W. C., Lagattuta, D., Leung, J. S.-Y., Jauzac, M., Li, L., Luu, T. V. T., Massey, R., McCleary, J. E., Nagy, J. M., Netterfield, C. B., Paracha, E., …Vitorelli, A. Z. (2024). SuperBIT Superpressure Flight Instrument Overview and Performance: Near-diffraction-limited Astronomical Imaging from the Stratosphere. Astronomical Journal, 168(2), Article 85. https://doi.org/10.3847/1538-3881/ad5840

SuperBIT was a 0.5 m near-UV to near-infrared wide-field telescope that launched on a NASA superpressure balloon into the stratosphere from New Zealand for a 45-night flight. SuperBIT acquired multiband images of galaxy clusters to study the properti... Read More about SuperBIT Superpressure Flight Instrument Overview and Performance: Near-diffraction-limited Astronomical Imaging from the Stratosphere.

Unveiling lens light complexity with a novel multi-Gaussian expansion approach for strong gravitational lensing (2024)
Journal Article
He, Q., Nightingale, J. W., Amvrosiadis, A., Robertson, A., Cole, S., Frenk, C. S., Massey, R., Li, R., Cao, X., Lange, S. C., & França, J. P. C. (2024). Unveiling lens light complexity with a novel multi-Gaussian expansion approach for strong gravitational lensing. Monthly Notices of the Royal Astronomical Society, 532(2), 2441-2462. https://doi.org/10.1093/mnras/stae1577

In a strong gravitational lensing system, the distorted light from a source is analysed to infer the properties of the lens. However, light emitted by the lens itself can contaminate the image of the source, introducing systematic errors in the analy... Read More about Unveiling lens light complexity with a novel multi-Gaussian expansion approach for strong gravitational lensing.

Scanning for dark matter subhaloes in Hubble Space Telescope imaging of 54 strong lenses (2023)
Journal Article
Nightingale, J. W., He, Q., Cao, X., Amvrosiadis, A., Etherington, A., Frenk, C. S., Hayes, R. G., Robertson, A., Cole, S., Lange, S., Li, R., & Massey, R. (2024). Scanning for dark matter subhaloes in Hubble Space Telescope imaging of 54 strong lenses. Monthly Notices of the Royal Astronomical Society, 527(4), 10480-10506. https://doi.org/10.1093/mnras/stad3694

The cold dark matter (DM) model predicts that every galaxy contains thousands of DM subhaloes; almost all other DM models include a physical process that smooths away the subhaloes. The subhaloes are invisible, but could be detected via strong gravit... Read More about Scanning for dark matter subhaloes in Hubble Space Telescope imaging of 54 strong lenses.

Data Downloaded via Parachute from a NASA Super-Pressure Balloon (2023)
Journal Article
Sirks, E. L., Massey, R., Gill, A. S., Anderson, J., Benton, S. J., Brown, A. M., Clark, P., English, J., Everett, S. W., Fraisse, A. A., Franco, H., Hartley, J. W., Harvey, D., Holder, B., Hunter, A., Huff, E. M., Hynous, A., Jauzac, M., Jones, W. C., Joyce, N., …Vassilakis, G. N. (2023). Data Downloaded via Parachute from a NASA Super-Pressure Balloon. Aerospace, 10(11), Article 960. https://doi.org/10.3390/aerospace10110960

In April 2023, the superBIT telescope was lifted to the Earth’s stratosphere by a helium-filled super-pressure balloon to acquire astronomical imaging from above (99.5% of) the Earth’s atmosphere. It was launched from New Zealand and then, for 40 day... Read More about Data Downloaded via Parachute from a NASA Super-Pressure Balloon.

Beyond the bulge–halo conspiracy? Density profiles of early-type galaxies from extended-source strong lensing (2023)
Journal Article
Etherington, A., Nightingale, J. W., Massey, R., Robertson, A., Cao, X., Amvrosiadis, A., Cole, S., Frenk, C. S., He, Q., Lagattuta, D. J., Lange, S., & Li, R. (2023). Beyond the bulge–halo conspiracy? Density profiles of early-type galaxies from extended-source strong lensing. Monthly Notices of the Royal Astronomical Society, 521(4), 6005-6018. https://doi.org/10.1093/mnras/stad582

Observations suggest that the dark matter and stars in early-type galaxies ‘conspire’ to produce a surprisingly simple distribution of total mass, ρ(r) ∝ ρ−γ, with γ ≈ 2. We measure the distribution of mass in 48 early-type galaxies that gravitationa... Read More about Beyond the bulge–halo conspiracy? Density profiles of early-type galaxies from extended-source strong lensing.

PyAutoGalaxy: Open-Source Multiwavelength Galaxy Structure & Morphology (2023)
Journal Article
Nightingale, J. W., Amvrosiadis, A., Hayes, R. G., He, Q., Etherington, A., Cao, X., Cole, S., Frawley, J., Frenk, C. S., Lange, S., Li, R., Massey, R. J., Negrello, M., & 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.

Constraints on dark matter self-interaction from the internal density profiles of X-COP galaxy clusters (2022)
Journal Article
Eckert, D., Ettori, S., Robertson, A., Massey, R., Pointecouteau, E., Harvey, D., & McCarthy, I. (2022). Constraints on dark matter self-interaction from the internal density profiles of X-COP galaxy clusters. Astronomy & Astrophysics, 666, Article A41. https://doi.org/10.1051/0004-6361/202243205

The fundamental properties of the postulated dark matter (DM) affect the internal structure of gravitationally bound structures. In the cold dark matter paradigm, DM particles interact only via gravity. Their distribution is well represented by an Ei... Read More about Constraints on dark matter self-interaction from the internal density profiles of X-COP galaxy clusters.

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., Amvrosiadis, A., Amorisco, N. C., He, Q., Etherington, A., Cole, 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., Amvrosiadis, A., Li, R., Cao, X., & 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., Etherington, A., Frenk, C. S., Li, R., Massey, R., & 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.

Unequal-mass mergers of dark matter haloes with rare and frequent self-interactions (2021)
Journal Article
Fischer, M. S., Brüggen, M., Schmidt-Hoberg, K., Dolag, K., Ragagnin, A., & Robertson, A. (2022). Unequal-mass mergers of dark matter haloes with rare and frequent self-interactions. Monthly Notices of the Royal Astronomical Society, 510(3), 4080-4099. https://doi.org/10.1093/mnras/stab3544

Dark matter (DM) self-interactions have been proposed to solve problems on small length scales within the standard cold DM cosmology. Here, we investigate the effects of DM self-interactions in merging systems of galaxies and galaxy clusters with equ... Read More about Unequal-mass mergers of dark matter haloes with rare and frequent self-interactions.

Testing extensions to ΛCDM on small scales with forthcoming cosmic shear surveys (2021)
Journal Article
Stafford, S. G., McCarthy, I. G., Kwan, J., Brown, S. T., Font, A. S., & Robertson, A. (2021). Testing extensions to ΛCDM on small scales with forthcoming cosmic shear surveys. Monthly Notices of the Royal Astronomical Society, 508(2), 2537-2555. https://doi.org/10.1093/mnras/stab2787

We investigate the constraining power of forthcoming Stage-IV weak lensing surveys (Euclid, LSST, and NGRST) for extensions to the Lambda cold dark matter model on small scales, via their impact on the cosmic shear power spectrum. We use high-resolut... Read More about Testing extensions to ΛCDM on small scales with forthcoming cosmic shear surveys.

The impact of self-interacting dark matter on the intrinsic alignments of galaxies (2021)
Journal Article
Harvey, D., Chisari, N. E., Robertson, A., & McCarthy, I. G. (2021). The impact of self-interacting dark matter on the intrinsic alignments of galaxies. Monthly Notices of the Royal Astronomical Society, 506(1), 441-451. https://doi.org/10.1093/mnras/stab1741

The formation and evolution of galaxies is known to be sensitive to tidal processes leading to intrinsic correlations between their shapes and orientations. Such correlations can be measured to high significance today, suggesting that cosmological in... Read More about The impact of self-interacting dark matter on the intrinsic alignments of galaxies.

N-body simulations of dark matter with frequent self-interactions (2021)
Journal Article
Fischer, M. S., Brüggen, M., Schmidt-Hoberg, K., Dolag, K., Kahlhoefer, F., Ragagnin, A., & Robertson, A. (2021). N-body simulations of dark matter with frequent self-interactions. Monthly Notices of the Royal Astronomical Society, 505(1), 851-868. https://doi.org/10.1093/mnras/stab1198

Self-interacting dark matter (SIDM) models have the potential to solve the small-scale problems that arise in the cold dark matter paradigm. Simulations are a powerful tool for studying SIDM in the context of astrophysics, but it is numerically chall... Read More about N-body simulations of dark matter with frequent self-interactions.

The galaxy–galaxy strong lensing cross-sections of simulated ΛCDM galaxy clusters (2021)
Journal Article
Robertson, A. (2021). The galaxy–galaxy strong lensing cross-sections of simulated ΛCDM galaxy clusters. Monthly Notices of the Royal Astronomical Society: Letters, 504(1), L7-L11. https://doi.org/10.1093/mnrasl/slab028

We investigate a recent claim that observed galaxy clusters produce an order of magnitude more galaxy–galaxy strong lensing (GGSL) than simulated clusters in a Λ cold dark matter (CDM) cosmology. We take galaxy clusters from the C-EAGLE hydrodynamica... Read More about The galaxy–galaxy strong lensing cross-sections of simulated ΛCDM galaxy clusters.

PyAutoLens: Open-Source Strong Gravitational Lensing (2021)
Journal Article
Nightingale, J., Hayes, R., Kelly, A., Amvrosiadis, A., Etherington, A., He, Q., Li, N., Cao, X., Frawley, J., Cole, S., Enia, A., Frenk, C., Harvey, D., Li, R., Massey, R., Negrello, M., & 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.

From dwarf galaxies to galaxy clusters: Self-Interacting Dark Matter over 7 orders of magnitude in halo mass (2021)
Journal Article
Bondarenko, K., Sokolenko, A., Boyarsky, A., Robertson, A., Harvey, D., & Revaz, Y. (2021). From dwarf galaxies to galaxy clusters: Self-Interacting Dark Matter over 7 orders of magnitude in halo mass. Journal of Cosmology and Astroparticle Physics, 2021(01), Article 043. https://doi.org/10.1088/1475-7516/2021/01/043

In this paper we study the density profiles of self-interacting dark matter (SIDM) haloes spanning the full observable mass range, from dwarf galaxies to galaxy clusters. Using realistic simulations that model the baryonic physics relevant for galaxy... Read More about From dwarf galaxies to galaxy clusters: Self-Interacting Dark Matter over 7 orders of magnitude in halo mass.

Velocity-dependent self-interacting dark matter from groups and clusters of galaxies (2021)
Journal Article
Sagunski, L., Gad-Nasr, S., Colquhoun, B., Robertson, A., & Tulin, S. (2021). Velocity-dependent self-interacting dark matter from groups and clusters of galaxies. Journal of Cosmology and Astroparticle Physics, 2021(01), Article 024. https://doi.org/10.1088/1475-7516/2021/01/024

We probe the self-interactions of dark matter with relaxed galaxy groups and clusters using observational data from strong and weak lensing and stellar kinematics. Our analysis uses the Jeans formalism and considers a wider range of systematic effect... Read More about Velocity-dependent self-interacting dark matter from groups and clusters of galaxies.