The candidate intermediate-mass black hole in the globular cluster M54

J. M. Wrobel, J. E. Greene, L. C. Ho

Research output: Contribution to journalArticlepeer-review

22 Scopus citations


Ibata et al. reported evidence for density and kinematic cusps in the Galactic globular cluster M54, possibly due to the presence of a 9400 M black hole. Radiative signatures of accretion onto M54's candidate intermediate-mass black hole (IMBH) could bolster the case for its existence. Analysis of new Chandra and recent Hubble Space Telescope astrometry rules out the X-ray counterpart to the candidate IMBH suggested by Ibata et al. If an IMBH exists in M54, then it has an Eddington ratio of L(0.3-8 keV)/L(Edd) < 1.4 × 10-10, more similar to that of the candidate IMBH in M15 than that in G1. From new imaging with the NRAO Very Large Array, the luminosity of the candidate IMBH is L(8.5 GHz) < 3.6 × 10 29ergs-1 (3σ). Two background active galaxies discovered toward M54 could serve as probes of its intracluster medium.

Original languageEnglish (US)
Article number113
JournalAstronomical Journal
Issue number4
StatePublished - Oct 2011
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science


  • X-rays: general
  • black hole physics
  • globular clusters: individual (M54)
  • radio continuum: general


Dive into the research topics of 'The candidate intermediate-mass black hole in the globular cluster M54'. Together they form a unique fingerprint.

Cite this