Lost but not forgotten: Intracluster light in galaxy groups and clusters

Tahlia DeMaio, Anthony H. Gonzalez, Ann Zabludoff, Dennis Zaritsky, Thomas Connor, Megan Donahue, John S. Mulchaey

Research output: Contribution to journalArticlepeer-review

55 Scopus citations


With Hubble Space Telescope imaging, we investigate the progenitor population and formation mechanisms of the intracluster light (ICL) for 23 galaxy groups and clusters at 0.29 ≤z≤0.89. The colour gradients of the BCG+ICL become bluer with increasing radius out to 53-100 kpc for all but one system, suggesting that violent relaxation after major mergers with the BCG cannot be the dominant source of ICL. The BCG+ICL luminosities and stellar masses are too large for the ICL stars to come from the dissolution of dwarf galaxies alone, given the observed evolution of the faint end of the cluster galaxy luminosity function, implying instead that the ICL grows from the stripping of more massive galaxies. Using the colours of cluster members from the CLASH high-mass sample, we place conservative lower limits on the luminosities of galaxies from which the ICL at r < 100 kpc could originate via stripping. We find that the ICL at 100 kpc has a colour similar to a 1010.0 M⊙ galaxy and that 75 per cent of the total BCG+ICL luminosity at r < 100 kpc is consistent with originating in galaxies with L > 0.2 LM* (log(M* [M⊙]) > 10.4), assuming conservatively that these galaxies are completely disrupted. We conclude that the tidal stripping of massive galaxies is the likely source of the intracluster light from 10 to 100 kpc for galaxy groups and clusters.

Original languageEnglish (US)
Pages (from-to)3009-3031
Number of pages23
JournalMonthly Notices of the Royal Astronomical Society
Issue number3
StatePublished - Mar 1 2018


  • CD
  • CD- galaxies: evolution
  • Galaxies: clusters: general
  • Galaxies: elliptical and lenticular
  • Galaxies: elliptical and lenticular
  • Galaxies: formation

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science


Dive into the research topics of 'Lost but not forgotten: Intracluster light in galaxy groups and clusters'. Together they form a unique fingerprint.

Cite this