Illuminating a dark lens: A type ia supernova magnified by the frontier fields galaxy cluster abell 2744

Published

Journal Article

© 2015. The American Astronomical Society. All rights reserved. SN HFF14Tom is a Type Ia SN discovered at Z = 1.3457 ± 0.0001 behind the galaxy cluster Abell 2744 (Z = 0.308). In a cosmology-independent analysis, we find that HFF14Tom is 0.77 ± 0.15 mag brighter than unlensed Type Ia SNe at similar redshift, implying a lensing magnification of μobs = 2.03 ± 0.29. This observed magnification provides a rare opportunity for a direct empirical test of galaxy cluster lens models. Here we test 17 lens models, 13 of which were generated before the SN magnification was known, qualifying as pure "blind tests. " The models are collectively fairly accurate: 8 of the models deliver median magnifications that are consistent with the measured μ to within 1λ. However, there is a subtle systematic bias: the significant disagreements all involve models overpredicting the magnification. We evaluate possible causes for this mild bias, and find no single physical or methodological explanation to account for it. We do find that model accuracy can be improved to some extent with stringent quality cuts on multiply imaged systems, such as requiring that a large fraction have spectroscopic redshifts. In addition to testing model accuracies as we have done here, Type Ia SN magnifications could also be used as inputs for future lens models of Abell 2744 and other clusters, providing valuable constraints in regions where traditional strong- and weak-lensing information is unavailable.

Full Text

Duke Authors

Cited Authors

  • Rodney, SA; Patel, B; Scolnic, D; Foley, RJ; Molino, A; Brammer, G; Jauzac, M; Brada─Ź, M; Broadhurst, T; Coe, D; Diego, JM; Graur, O; Hjorth, J; Hoag, A; W. Jha, S; Johnson, TL; Kelly, P; Lam, D; McCully, C; Medezinski, E; Meneghetti, M; Merten, J; Richard, J; Riess, A; Sharon, K; Strolger, LG; Treu, T; Wang, X; Williams, LLR; Zitrin, A

Published Date

  • September 20, 2015

Published In

Volume / Issue

  • 811 / 1

Electronic International Standard Serial Number (EISSN)

  • 1538-4357

International Standard Serial Number (ISSN)

  • 0004-637X

Digital Object Identifier (DOI)

  • 10.1088/0004-637X/811/1/70

Citation Source

  • Scopus