All Outputs (24)

The COSMOS-Web ring: Spectroscopic confirmation of the background source at z = 5.1 (2025)
Journal Article
Shuntov, M., Jin, S., Mercier, W., Kartaltepe, J. S., Larson, R., Khostovan, A. A., Gavazzi, R., Nightingale, J. W., Ilbert, O., Arango-Toro, R., Franco, M., Akins, H. B., Casey, C. M., McCracken, H. J., Ciesla, L., Magdis, G. E., Amvrosiadis, A., Enia, A., Faisst, A. L., Koekemoer, A. M., …Vaccari, M. (2025). The COSMOS-Web ring: Spectroscopic confirmation of the background source at z = 5.1. Astronomy & Astrophysics, 696, Article L14. https://doi.org/10.1051/0004-6361/202554273

We report the spectroscopic confirmation of the background source of the most distant Einstein ring known to date, the COSMOS-Web ring. This system consists of a complete Einstein ring at z = 5.1, which is lensed by a massive early-type galaxy at z ∼... Read More about The COSMOS-Web ring: Spectroscopic confirmation of the background source at z = 5.1.

Galaxy mass modelling from multiwavelength JWST strong lens analysis: dark matter substructure, angular mass complexity, or both? (2025)
Journal Article
Lange, S. C., Amvrosiadis, A., Nightingale, J. W., He, Q., Frenk, C. S., Robertson, A., Cole, S., Massey, R., Cao, X., Li, R., & Wang, K. (2025). Galaxy mass modelling from multiwavelength JWST strong lens analysis: dark matter substructure, angular mass complexity, or both?. Monthly Notices of the Royal Astronomical Society, 539(2), 704-726. https://doi.org/10.1093/mnras/staf491

We analyse two galaxy-scale strong gravitational lenses, SPT0418-47 and SPT2147-50, using JWST NIRCam imaging across multiple filters. To account for angular complexity in the lens mass distribution, we introduce multipole perturbations with orders m... Read More about Galaxy mass modelling from multiwavelength JWST strong lens analysis: dark matter substructure, angular mass complexity, or both?.

The onset of bar formation in a massive galaxy at z ∼ 3.8 (2025)
Journal Article
Amvrosiadis, A., Lange, S., Nightingale, J. W., He, Q., Frenk, C. S., Oman, K. A., Smail, I., Swinbank, A. M., Fragkoudi, F., Gadotti, D. A., Cole, S., Borsato, E., Robertson, A., Massey, R., Cao, X., & Li, R. (2025). The onset of bar formation in a massive galaxy at z ∼ 3.8. Monthly Notices of the Royal Astronomical Society, 537(2), 1163-1181. https://doi.org/10.1093/mnras/staf048

We examine the morphological and kinematical properties of SPT-2147, a strongly lensed, massive, dusty, star-forming galaxy at z = 3.762. Combining data from JWST, Hubble Space Telescope, and ALMA, we study the galaxy’s stellar emission, dust continu... Read More about The onset of bar formation in a massive galaxy at z ∼ 3.8.

The kinematics of massive high-redshift dusty star-forming galaxies (2024)
Journal Article
Amvrosiadis, A., Wardlow, J. L., Birkin, J. E., Smail, I., Swinbank, A. M., Nightingale, J., Bertoldi, F., Brandt, W. N., Casey, C. M., Chapman, S. C., Chen, C. C., Cox, P., da Cunha, E., Dannerbauer, H., Dudzevičiūte, U., Gullberg, B., Hodge, J. A., Knudsen, K. K., Menten, K., Walter, F., & van der Werf, P. (2025). The kinematics of massive high-redshift dusty star-forming galaxies. Monthly Notices of the Royal Astronomical Society, 536(4), 3757-3783. https://doi.org/10.1093/mnras/stae2760

We present a new method for modelling the kinematics of galaxies from interferometric observations by performing the optimization of the kinematic model parameters directly in visibility space instead of the conventional approach of fitting velocity... Read More about The kinematics of massive high-redshift dusty star-forming galaxies.

Gravitational lensing reveals cool gas within 10-20 kpc around a quiescent galaxy (2024)
Journal Article
Barone, T. M., Kacprzak, G. G., Nightingale, J. W., Nielsen, N. M., Glazebrook, K., Tran, K.-V. H., Jones, T., Nateghi, H., Vasan Gopala Chandrasekaran, K., Sahu, N., Nanayakkara, T., Skobe, H., van de Sande, J., Lopez, S., & Lewis, G. F. (2024). Gravitational lensing reveals cool gas within 10-20 kpc around a quiescent galaxy. Communications Physics, 7(1), Article 286. https://doi.org/10.1038/s42005-024-01778-4

While quiescent galaxies have comparable amounts of cool gas in their outer circumgalactic medium (CGM) compared to star-forming galaxies, they have significantly less interstellar gas. However, open questions remain on the processes causing galaxies... Read More about Gravitational lensing reveals cool gas within 10-20 kpc around a quiescent galaxy.

The COSMOS-Web ring: In-depth characterization of an Einstein ring lensing system at z ∼ 2 (2024)
Journal Article
Mercier, W., Shuntov, M., Gavazzi, R., Nightingale, J. W., Arango, R., Ilbert, O., Amvrosiadis, A., Ciesla, L., Casey, C. M., Jin, S., Faisst, A. L., Andika, I. T., Drakos, N. E., Enia, A., Franco, M., Gillman, S., Gozaliasl, G., Hayward, C. C., Huertas-Company, M., Kartaltepe, J. S., …Vijayan, A. P. (2024). The COSMOS-Web ring: In-depth characterization of an Einstein ring lensing system at z ∼ 2. Astronomy & Astrophysics, 687, Article A61. https://doi.org/10.1051/0004-6361/202348095

Aims. We provide an in-depth analysis of the COSMOS-Web ring, an Einstein ring at z ≈ 2 that we serendipitously discovered during the data reduction of the COSMOS-Web survey and that could be the most distant lens discovered to date.

Methods. We e... Read More about The COSMOS-Web ring: In-depth characterization of an Einstein ring lensing system at z ∼ 2.

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.

Strong gravitational lensing’s ‘external shear’ is not shear (2024)
Journal Article
Etherington, A., Nightingale, J., Massey, R., Tam, S.-I., Cao, X., Niemiec, A., He, Q., Robertson, A., Li, R., Amvrosiadis, A., Cole, S., Diego, J., Frenk, C., Frye, B., Harvey, D., Jauzac, M., Koekemoer, A., Lagattuta, D., Lange, S., Limousin, M., …Steinhardt, C. (2024). Strong gravitational lensing’s ‘external shear’ is not shear. Monthly Notices of the Royal Astronomical Society, 531(3), 3684-3697. https://doi.org/10.1093/mnras/stae1375

The distribution of mass in galaxy-scale strong gravitational lenses is often modelled as an elliptical power-law plus ‘external shear’, which notionally accounts for neighbouring galaxies and cosmic shear along our line of sight. A small amount of e... Read More about Strong gravitational lensing’s ‘external shear’ is not shear.

A Glimpse of the Stellar Populations and Elemental Abundances of Gravitationally Lensed, Quiescent Galaxies at z ≳ 1 with Keck Deep Spectroscopy (2023)
Journal Article
Zhuang, Z., Leethochawalit, N., Kirby, E. N., Nightingale, J. W., Steidel, C. C., Glazebrook, K., …Jacobs, C. (2023). A Glimpse of the Stellar Populations and Elemental Abundances of Gravitationally Lensed, Quiescent Galaxies at z ≳ 1 with Keck Deep Spectroscopy. Astrophysical Journal, 948(2), Article 132. https://doi.org/10.3847/1538-4357/acc79b

Gravitational lenses can magnify distant galaxies, allowing us to discover and characterize the stellar populations of intrinsically faint, quiescent galaxies that are otherwise extremely difficult to directly observe at high redshift from ground-bas... Read More about A Glimpse of the Stellar Populations and Elemental Abundances of Gravitationally Lensed, Quiescent Galaxies at z ≳ 1 with Keck Deep Spectroscopy.

Abell 1201: detection of an ultramassive black hole in a strong gravitational lens (2023)
Journal Article
Nightingale, J., Smith, R. J., He, Q., O’Riordan, C. M., Kegerreis, J. A., Amvrosiadis, A., Edge, A. C., Etherington, A., Hayes, R. G., Kelly, A., Lucey, J. R., & Massey, R. J. (2023). Abell 1201: detection of an ultramassive black hole in a strong gravitational lens. Monthly Notices of the Royal Astronomical Society, 521(3), 3298-3322. https://doi.org/10.1093/mnras/stad587

Supermassive black holes (SMBHs) are a key catalyst of galaxy formation and evolution, leading to an observed correlation between SMBH mass MBH and host galaxy velocity dispersion σe. Outside the local Universe, measurements of MBH are usually only p... Read More about Abell 1201: detection of an ultramassive black hole in a strong gravitational lens.

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.

The “External” Shears In Strong Lens Models (2022)
Journal Article
Nightingale, J. W., Etherington, A., & Massey, R. (2022). The “External” Shears In Strong Lens Models. Proceedings of the International Astronomical Union, 18(S381), 13-16. https://doi.org/10.1017/s1743921323003691

The distribution of mass in galaxy-scale strong gravitational lenses is often modelled as an elliptical power law plus ‘external shear’, which notionally accounts for line-of-sight galaxies and cosmic shear. We argue that it does not, using three lin... Read More about The “External” Shears In Strong Lens Models.

Testing strong lensing subhalo detection with a cosmological simulation (2022)
Journal Article
He, Q., Nightingale, J., Robertson, A., Amvrosiadis, A., Cole, S., Frenk, C. S., Massey, R., Li, R., Amorisco, N. C., Metcalf, R. B., Cao, X., & Etherington, A. (2023). Testing strong lensing subhalo detection with a cosmological simulation. Monthly Notices of the Royal Astronomical Society, 518(1), 220-239. https://doi.org/10.1093/mnras/stac2779

Strong gravitational lensing offers a compelling test of the cold dark matter paradigm, as it allows for subhaloes with masses of ∼109 M⊙ and below to be detected. We test commonly-used techniques for detecting subhaloes superposed in images of stron... Read More about Testing strong lensing subhalo detection with a cosmological simulation.

Automated galaxy-galaxy strong lens modelling: No lens left behind (2022)
Journal Article
Etherington, A., Nightingale, J. W., Massey, R., Cao, X., Robertson, A., Amorisco, N. C., Amvrosiadis, A., Cole, S., Frenk, C. S., He, Q., Li, R., & Tam, S.-I. (2022). Automated galaxy-galaxy strong lens modelling: No lens left behind. Monthly Notices of the Royal Astronomical Society, 517(3), 3275-3302. https://doi.org/10.1093/mnras/stac2639

The distribution of dark and luminous matter can be mapped around galaxies that gravitationally lens background objects into arcs or Einstein rings. New surveys will soon observe hundreds of thousands of galaxy lenses, and current, labour-intensive a... Read More about Automated galaxy-galaxy strong lens modelling: No lens left behind.

Microlensing and the type Ia supernova iPTF16geu (2022)
Journal Article
Diego, J., Bernstein, G., Chen, W., Goobar, A., Johansson, J., Kelly, P., Mörtsell, E., & Nightingale, J. (2022). Microlensing and the type Ia supernova iPTF16geu. Astronomy & Astrophysics, 662, Article A34. https://doi.org/10.1051/0004-6361/202143009

The observed magnifications and light curves of the quadruply imaged iPTF16geu supernova (SN) offers a unique opportunity to study a lens system with a variety of independent constraints. The four observed positions can be used to constrain the macro... Read More about Microlensing and the type Ia supernova iPTF16geu.

Galaxy–galaxy strong lens perturbations: line-of-sight haloes versus lens subhaloes (2022)
Journal Article
He, Q., Li, R., Frenk, C. S., Nightingale, J., Cole, S., Amorisco, N. C., Massey, R., Robertson, A., Etherington, A., Amvrosiadis, A., & Cao, X. (2022). Galaxy–galaxy strong lens perturbations: line-of-sight haloes versus lens subhaloes. Monthly Notices of the Royal Astronomical Society, 512(4), 5862-5873. https://doi.org/10.1093/mnras/stac759

We rederive the number density of intervening line-of-sight haloes relative to lens subhaloes in galaxy-galaxy strong lensing observations, where these perturbers can generate detectable image fluctuations. Previous studies have calculated the detect... Read More about Galaxy–galaxy strong lens perturbations: line-of-sight haloes versus lens subhaloes.

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.

Euclid preparation XIII. Forecasts for galaxy morphology with the Euclid Survey using deep generative models (2022)
Journal Article
Bretonnière, H., Huertas-Company, M., Boucaud, A., Lanusse, F., Jullo, E., Merlin, E., Tuccillo, D., Castellano, M., Brinchmann, J., Conselice, C., Dole, H., Cabanac, R., Courtois, H., Castander, F., Duc, P., Fosalba, P., Guinet, D., Kruk, S., Kuchner, U., Serrano, S., …Knapen, J. (2022). Euclid preparation XIII. Forecasts for galaxy morphology with the Euclid Survey using deep generative models. Astronomy & Astrophysics, 657, Article A90. https://doi.org/10.1051/0004-6361/202141393

We present a machine learning framework to simulate realistic galaxies for the Euclid Survey, producing more complex and realistic galaxies than the analytical simulations currently used in Euclid. The proposed method combines a control on galaxy sha... Read More about Euclid preparation XIII. Forecasts for galaxy morphology with the Euclid Survey using deep generative models.

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.