Professor Richard Massey's Outputs (193)

The PAU Survey and Euclid: Improving broadband photometric redshifts with multi-task learning (2023)
Journal Article
Cabayol, L., Eriksen, M., Carretero, J., Casas, R., Castander, F., Fernández, E., Garcia-Bellido, J., Gaztanaga, E., Hildebrandt, H., Hoekstra, H., Joachimi, B., Miquel, R., Padilla, C., Pocino, A., Sanchez, E., Serrano, S., Sevilla, I., Siudek, M., Tallada-Crespí, P., Aghanim, N., …Tramacere, A. (2023). The PAU Survey and Euclid: Improving broadband photometric redshifts with multi-task learning. Astronomy & Astrophysics, 671, Article A153. https://doi.org/10.1051/0004-6361/202245027

Current and future imaging surveys require photometric redshifts (photo-zs) to be estimated for millions of galaxies. Improving the photo-z quality is a major challenge but is needed to advance our understanding of cosmology. In this paper we explore... Read More about The PAU Survey and Euclid: Improving broadband photometric redshifts with multi-task learning.

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.

On the gravitational lensing interpretation of three gravitational wave detections in the mass gap by LIGO and Virgo (2023)
Journal Article
Bianconi, M., Smith, G. P., Nicholl, M., Ryczanowski, D., Richard, J., Jauzac, M., Massey, R., Robertson, A., Sharon, K., & Ridley, E. (2023). On the gravitational lensing interpretation of three gravitational wave detections in the mass gap by LIGO and Virgo. Monthly Notices of the Royal Astronomical Society, 521(3), 3421-3430. https://doi.org/10.1093/mnras/stad673

We search for gravitational wave (GW) events from LIGO-Virgo’s third run that may have been affected by gravitational lensing. Gravitational lensing delays the arrival of GWs, and alters their amplitude – thus biasing the inferred progenitor masses.... Read More about On the gravitational lensing interpretation of three gravitational wave detections in the mass gap by LIGO and Virgo.

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.

Enabling discovery of gravitationally lensed explosive transients: a new method to build an all-sky watch list of groups and clusters of galaxies (2023)
Journal Article
Ryczanowski, D., Smith, G. P., Bianconi, M., McGee, S., Robertson, A., Massey, R., & Jauzac, M. (2023). Enabling discovery of gravitationally lensed explosive transients: a new method to build an all-sky watch list of groups and clusters of galaxies. Monthly Notices of the Royal Astronomical Society, 520(2), 2547-2557. https://doi.org/10.1093/mnras/stad231

Cross-referencing a watch list of galaxy groups and clusters with transient detections from real-time streams of wide-field survey data is a promising method for discovering gravitationally lensed explosive transients, including supernovae, kilonovae... Read More about Enabling discovery of gravitationally lensed explosive transients: a new method to build an all-sky watch list of groups and clusters of galaxies.

Discovering gravitationally lensed gravitational waves: predicted rates, candidate selection, and localization with the Vera Rubin Observatory (2023)
Journal Article
Smith, G. P., Robertson, A., Mahler, G., Nicholl, M., Ryczanowski, D., Bianconi, M., Sharon, K., Massey, R., Richard, J., & Jauzac, M. (2023). Discovering gravitationally lensed gravitational waves: predicted rates, candidate selection, and localization with the Vera Rubin Observatory. Monthly Notices of the Royal Astronomical Society, 520(1), 702-721. https://doi.org/10.1093/mnras/stad140

Secure confirmation that a gravitational wave (GW) has been gravitationally lensed would bring together these two pillars of General Relativity for the first time. This breakthrough is challenging for many reasons, including: GW sky localization unce... Read More about Discovering gravitationally lensed gravitational waves: predicted rates, candidate selection, and localization with the Vera Rubin Observatory.

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.

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.

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.

Euclid preparation XX. The Complete Calibration of the Color–Redshift Relation survey: LBT observations and data releas (2022)
Journal Article
Saglia, R., De Nicola, S., Fabricius, M., Guglielmo, V., Snigula, J., Zöller, R., Bender, R., Heidt, J., Masters, D., Stern, D., Paltani, S., Amara, A., Auricchio, N., Baldi, M., Bodendorf, C., Bonino, D., Branchini, E., Brescia, M., Brinchmann, J., Camera, S., …Viel, M. (2022). Euclid preparation XX. The Complete Calibration of the Color–Redshift Relation survey: LBT observations and data releas. Astronomy & Astrophysics, 664, Article A196. https://doi.org/10.1051/0004-6361/202243604

The Complete Calibration of the Color–Redshift Relation survey (C3R2) is a spectroscopic program designed to empirically calibrate the galaxy color–redshift relation to the Euclid depth (IE = 24.5), a key ingredient for the success of Stage IV dark e... Read More about Euclid preparation XX. The Complete Calibration of the Color–Redshift Relation survey: LBT observations and data releas.

Pilot-WINGS: An extended MUSE view of the structure of Abell 370 (2022)
Journal Article
Lagattuta, D. J., Richard, J., Bauer, F. E., Cerny, C., Claeyssens, A., Guaita, L., Jauzac, M., Jeanneau, A., Koekemoer, A. M., Mahler, G., Prieto Lyon, G., Acebron, A., Meneghetti, M., Niemiec, A., Zitrin, A., Bianconi, M., Connor, T., Cen, R., Edge, A., Faisst, A. L., …Weaver, J. R. (2022). Pilot-WINGS: An extended MUSE view of the structure of Abell 370. Monthly Notices of the Royal Astronomical Society, 514(1), 497-517. https://doi.org/10.1093/mnras/stac418

We investigate the strong-lensing cluster Abell 370 (A370) using a wide Integral Field Unit (IFU) spectroscopic mosaic from the Multi-Unit Spectroscopic Explorer (MUSE). IFU spectroscopy provides significant insight into the structure and mass conten... Read More about Pilot-WINGS: An extended MUSE view of the structure of Abell 370.

Dealing with density discontinuities in planetary SPH simulations (2022)
Journal Article
Ruiz-Bonilla, S., Borrow, J., Eke, V., Kegerreis, J., Massey, R., Sandnes, T., & Teodoro, L. (2022). Dealing with density discontinuities in planetary SPH simulations. Monthly Notices of the Royal Astronomical Society, 512(3), 4660-4668. https://doi.org/10.1093/mnras/stac857

Density discontinuities cannot be precisely modelled in standard formulations of smoothed particles hydrodynamics (SPH) because the density field is defined smoothly as a kernel-weighted sum of neighbouring particle masses. This is a problem when per... Read More about Dealing with density discontinuities in planetary SPH simulations.

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.

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.

Euclid preparation XVII. Cosmic Dawn Survey: Spitzer Space Telescope observations of the Euclid deep fields and calibration fields (2022)
Journal Article
Moneti, A., McCracken, H., Shuntov, M., Kauffmann, O., Capak, P., Davidzon, I., Ilbert, O., Scarlata, C., Toft, S., Weaver, J., Chary, R., Cuby, J., Faisst, A., Masters, D., McPartland, C., Mobasher, B., Sanders, D., Scaramella, R., Stern, D., Szapudi, I., …Hildebrandt, H. (2022). Euclid preparation XVII. Cosmic Dawn Survey: Spitzer Space Telescope observations of the Euclid deep fields and calibration fields. Astronomy & Astrophysics, 658, Article A126. https://doi.org/10.1051/0004-6361/202142361

We present a new infrared survey covering the three Euclid deep fields and four other Euclid calibration fields using Spitzer Space Telescope’s Infrared Array Camera (IRAC). We combined these new observations with all relevant IRAC archival data of t... Read More about Euclid preparation XVII. Cosmic Dawn Survey: Spitzer Space Telescope observations of the Euclid deep fields and calibration fields.

Weak gravitational lensing shear measurement with FPFS: analytical mitigation of noise bias and selection bias (2022)
Journal Article
Li, X., Li, Y., & Massey, R. (2022). Weak gravitational lensing shear measurement with FPFS: analytical mitigation of noise bias and selection bias. Monthly Notices of the Royal Astronomical Society, 511(4), 4850-4860. https://doi.org/10.1093/mnras/stac342

Dedicated ‘Stage IV’ observatories will soon observe the entire extragalactic sky, to measure the ‘cosmic shear’ distortion of galaxy shapes by weak gravitational lensing. To measure the apparent shapes of those galaxies, we present an improved versi... Read More about Weak gravitational lensing shear measurement with FPFS: analytical mitigation of noise bias and selection bias.

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.

Euclid: Forecasts from redshift-space distortions and the Alcock-Paczynski test with cosmic voids (2022)
Journal Article
Hamaus, N., Aubert, M., Pisani, A., Contarini, S., Verza, G., Cousinou, M. .-C., Escoffier, S., Hawken, A., Lavaux, G., Pollina, G., Wandelt, B., Weller, J., Bonici, M., Carbone, C., Guzzo, L., Kovacs, A., Marulli, F., Massara, E., Moscardini, L., Ntelis, P., …Romelli, E. (2022). Euclid: Forecasts from redshift-space distortions and the Alcock-Paczynski test with cosmic voids. Astronomy & Astrophysics, 658, Article A20. https://doi.org/10.1051/0004-6361/202142073

Euclid is poised to survey galaxies across a cosmological volume of unprecedented size, providing observations of more than a billion objects distributed over a third of the full sky. Approximately 20 million of these galaxies will have their spectro... Read More about Euclid: Forecasts from redshift-space distortions and the Alcock-Paczynski test with cosmic voids.