Beecroft Institute for Particle Astrophysics and Cosmology

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Calibrating baryonic effects in cosmic shear with external data in the LSST era

Monthly Notices of the Royal Astronomical Society (2025)

Authors:

Amy Wayland, David Alonso, and Matteo Zennaro

Abstract:

Cosmological constraints derived from weak lensing (WL) surveys are limited by baryonic effects, which suppress the non-linear matter power spectrum on small scales. By combining WL measurements with data from external tracers of the gas around massive structures, it is possible to calibrate baryonic effects and, therefore, obtain more precise cosmological constraints. In this study, we generate mock data for a Stage-IV weak lensing survey such as the Legacy Survey of Space and Time (LSST), X-ray gas fractions, and stacked kinetic Sunyaev-Zel'dovich (kSZ) measurements, to jointly constrain cosmological and astrophysical parameters describing baryonic effects (using the Baryon Correction Model - BCM). First, using WL data alone, we quantify the level to which the BCM parameters will need to be constrained to recover the cosmological constraints obtained under the assumption of perfect knowledge of baryonic feedback. We identify the most relevant baryonic parameters and determine that they must be calibrated to a precision of ∼10-20% to avoid significant degradation of the fiducial WL constraints. We forecast that long-term X-ray data from ∼5000 clusters should be able to reach this threshold for the parameters that characterise the abundance of hot virialised gas. Constraining the distribution of ejected gas presents a greater challenge, however, but we forecast that long-term kSZ data from a CMB-S4-like experiment should achieve the level of precision required for full self-calibration.
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syren-baryon: Analytic emulators for the impact of baryons on the matter power spectrum

(2025)

Authors:

Lukas Kammerer, Deaglan J Bartlett, Gabriel Kronberger, Harry Desmond, Pedro G Ferreira
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Euclid: Early Release Observations The intracluster light of Abell 2390

Astronomy and Astrophysics 698 (2025)

Authors:

A Ellien, M Montes, SL Ahad, P Dimauro, JB Golden-Marx, Y Jimenez-Teja, F Durret, C Bellhouse, JM Diego, SP Bamford, AH Gonzalez, NA Hatch, M Kluge, R Ragusa, E Slezak, JC Cuillandre, R Gavazzi, H Dole, G Mahler, G Congedo, T Saifollahi, N Aghanim, B Altieri, A Amara, S Andreon, N Auricchio, C Baccigalupi, M Baldi, A Balestra, S Bardelli, A Basset, P Battaglia, A Biviano, A Bonchi, D Bonino, E Branchini, M Brescia, J Brinchmann, A Caillat, S Camera, V Capobianco, C Carbone, VF Cardone, J Carretero, S Casas, M Castellano, G Castignani, S Cavuoti, A Cimatti, C Colodro-Conde, CJ Conselice, L Conversi, Y Copin, F Courbin, HM Courtois, M Cropper, AD Silva, H Degaudenzi, G De Lucia, AMD Giorgio, J Dinis, F Dubath, CAJ Duncan, X Dupac, S Dusini, M Farina, F Faustini, S Ferriol, S Fotopoulou, M Frailis, E Franceschi, S Galeotta, K George, B Gillis, C Giocoli, P Gómez-Alvarez, A Grazian, F Grupp, L Guzzo, SVH Haugan, J Hoar, H Hoekstra, W Holmes, F Hormuth, A Hornstrup, P Hudelot, K Jahnke, M Jhabvala, B Joachimi, E Keihänen, S Kermiche, A Kiessling, B Kubik, K Kuijken, M Kümmel, M Kunz, H Kurki-Suonio, R Laureijs, D Le Mignant, S Ligori

Abstract:

Intracluster light (ICL) provides a record of the dynamical interactions undergone by clusters, giving clues on cluster formation and evolution. Here, we analyse the properties of ICL in the massive cluster Abell 2390 at redshift z = 0.228. Our analysis is based on the deep images obtained by the Euclid mission as part of the Early Release Observations in the near-infrared (YE, JE, HE bands), using the NISP instrument in a 0.75 deg2 field. We subtracted a point–spread function (PSF) model and removed the Galactic cirrus contribution in each band after modelling it with the DAWIS software. We then applied three methods to detect, characterise, and model the ICL and the brightest cluster galaxy (BCG): the CICLE 2D multi-galaxy fitting; the DAWIS wavelet-based multiscale software; and a mask-based 1D profile fitting. We detect ICL out to 600 kpc. The ICL fractions derived by our three methods range between 18% and 36% (average of 24%), while the BCG+ICL fractions are between 21% and 41% (average of 29%), depending on the band and method. A galaxy density map based on 219 selected cluster members shows a strong cluster substructure to the south-east and a smaller feature to the north-west. Ellipticals dominate the cluster’s central region, with a centroid offset from the BCG by about 70 kpc and distribution following that of the ICL, while spirals do not trace the entire ICL but rather substructures. The comparison of the BCG+ICL, mass from gravitational lensing, and X-ray maps show that the BCG+ICL is the best tracer of substructures in the cluster. Based on colours, the ICL (out to about 400 kpc) seems to be built by the accretion of small systems (M ∼ 109.5 M ), or from stars coming from the outskirts of Milky Way-type galaxies (M ∼ 1010 M ). Though Abell 2390 does not seem to be undergoing a merger, it is not yet fully relaxed, since it has accreted two groups that have not fully merged with the cluster core. We estimate that the contributions to the inner 300 kpc of the ICL of the north-west and south-east subgroups are 21% and 9%, respectively.
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Galaxy size and mass build-up in the first 2 Gyr of cosmic history from multi-wavelength JWST NIRCam imaging

Astronomy & Astrophysics EDP Sciences 698 (2025) a30

Authors:

Natalie Allen, Pascal A Oesch, Sune Toft, Jasleen Matharu, Conor JR McPartland, Andrea Weibel, Gabe Brammer, Rebecca AA Bowler, Kei Ito, Rashmi Gottumukkala, Francesca Rizzo, Francesco Valentino, Rohan G Varadaraj, John R Weaver, Katherine E Whitaker
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SYREN-NEW: Precise formulae for the linear and nonlinear matter power spectra with massive neutrinos and dynamical dark energy

Astronomy & Astrophysics EDP Sciences 698 (2025) a1

Authors:

Ce Sui, Deaglan J Bartlett, Shivam Pandey, Harry Desmond, Pedro G Ferreira, Benjamin D Wandelt
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