Extreme magnification of an individual star at redshift 1.5 by a galaxy-cluster lens

Open Access
Authors
  • P.L. Kelly
  • J.M. Diego
  • S. Rodney
  • N. Kaiser
  • T. Broadhurst
  • A. Zitrin
  • T. Treu
  • P.G. Pérez-González
  • T. Morishita
  • M. Jauzac
  • J. Selsing
  • M. Oguri
  • L. Pueyo
  • T.W. Ross
  • A.V. Filippenko
  • N. Smith
  • J. Hjorth
  • S.B Cenko
  • X. Wang
  • D.A. Howell
  • J. Richard
  • B.L. Frye
  • S.W. Jha
  • R.J. Foley
  • C. Norman
  • M. Bradac
  • W. Zheng
  • G. Brammer
  • A.M. Benito
  • A. Cava
  • L. Christensen
  • S.E. de Mink
  • O. Graur
  • C. Grillo
  • R. Kawamata
  • J.-P. Kneib
  • T. Matheson
  • C. McCully
  • M. Nonino
  • I. Pérez-Fournon
  • A.G. Riess
  • P. Rosati
  • K.B. Schmidt
  • K. Sharon
  • B.J. Weiner
Publication date 04-2018
Journal Nature Astronomy
Volume | Issue number 2
Pages (from-to) 334-342
Organisations
  • Faculty of Science (FNWI) - Anton Pannekoek Institute for Astronomy (API)
Abstract
Galaxy-cluster gravitational lenses can magnify background galaxies by a total factor of up to ~50. Here we report an image of an individual star at redshift z = 1.49 (dubbed MACS J1149 Lensed Star 1) magnified by more than ×2,000. A separate image, detected briefly 0.26″ from Lensed Star 1, is probably a counterimage of the first star demagnified for multiple years by an object of ≳3 solar masses in the cluster. For reasonable assumptions about the lensing system, microlensing fluctuations in the stars’ light curves can yield evidence about the mass function of intracluster stars and compact objects, including binary fractions and specific stellar evolution and supernova models. Dark-matter subhaloes or massive compact objects may help to account for the two images’ long-term brightness ratio.
Document type Article
Language English
Published at https://doi.org/10.1038/s41550-018-0430-3
Published at https://arxiv.org/abs/1706.10279
Other links https://ui.adsabs.harvard.edu/abs/2018NatAs...2..334K/abstract
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