An improved Magellan weak lensing analysis of the galaxy cluster Abell 2744

¹ Dipartimento di Fisica, Università degli Studi di Milano, Via Celoria 16, 20133 Milano, Italy
e-mail: davide.abriola@unimi.it
² INAF-OAS, Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, via Gobetti 93/3, 40129 Bologna, Italy
³ INAF-OAT Osservatorio Astronomico di Trieste, via G. B. Tiepolo 11, 34131 Trieste, Italy
⁴ INAF-IASF Milano, via A. Corti 12, 20133 Milano, Italy
⁵ Dipartimento di Fisica e Scienze della Terra, Università degli Studi di Ferrara, via Saragat 1, 44122 Ferrara, Italy

Received: 5 September 2023
Accepted: 7 February 2024

Abstract

We present a new weak lensing analysis of the Hubble Frontier Fields galaxy cluster Abell 2744 (z = 0.308) using new Magellan/MegaCam multi-band gri imaging data. We carried out our study by applying brand-new PSF and shape measurement software that allow the use of multi-band data simultaneously, which we first tested on Subaru/Suprime-Cam BR_cz′ imaging data of the same cluster. The projected total mass of this system within 2.35 Mpc from the south-west BCG is (2.56 ± 0.26)×10¹⁵ M_⊙, which makes Abell 2744 one of the most massive clusters known. This value is consistent, within the errors, with previous weak lensing and dynamical studies. Our analysis reveals the presence of three high-density substructures, thus supporting the picture of a complex merging scenario. This result is also confirmed by a comparison with a recent strong lensing study based on high-resolution JWST imaging. Moreover, our reconstructed total mass profile nicely agrees with an extrapolation of the strong lensing best-fit model up to several megaparsecs from the BCG centre.