Lens statistics with gravitationally lensed yet morphologically regular images

Masayo Morioka, Toshifumi Futamase

Research output: Contribution to journalArticlepeer-review

2 Citations (Scopus)


GRAMORs are GRAvitationally highly magnified yet MORphologically regular images. An example of this phenomenon was discovered in the cluster MACS J1149.5+2223 in 2009. We investigate the lens statistics of GRAMORs in detail. Assuming a NFW profile for a sample of clusters, we calculate the expected number and redshift distribution of GRAMORs using parameters from COSMOS data for the number density of the background galaxy. A model with a cluster placed at z = 0.544 based on WMAP5 cosmology predicts the redshift of a GRAMOR at which is close to the observed z = 1.4906. These results show that the expected number of GRAMORs is about two per cluster in the most likely case, and thus a large number of GRAMORs would be observed in a systematic survey. The probability distribution function of source redshift for GRAMORs depends strongly on dark energy and may be useful for constraining the nature of dark energy.

Original languageEnglish
Article number184
JournalAstrophysical Journal
Issue number2
Publication statusPublished - 2015 Jun 1


  • cosmological parameters
  • galaxies: clusters: general
  • galaxies: clusters: individual (MACSJ1149.5 +2223)
  • gravitational lensing: strong

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science


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