XMM-Newton first-light observations of the Hickson galaxy group 16

MJL Turner, JN Reeves, Trevor Ponman, M Arnaud, M Barbera, PJ Bennie, M Boer, U Briel

Research output: Contribution to journalArticle

29 Citations (Scopus)


This paper presents the XMM-Newton first-light observations of the Hickson-16 compact group of galaxies. Groups are possibly the oldest large-scale structures in the Universe, pre-dating clusters of galaxies, and are highly evolved. This group of small galaxies, at a redshift of 0.0132 (or 80 Mpc) is exceptional in the having the highest concentration of starburst or AGN activity in the nearby Universe. So it is a veritable laboratory for the study of the relationship between galaxy interactions and nuclear activity. Previous optical emission line studies indicated a strong ionising continuum in the galaxies, but its origin, whether from starbursts, or AGN, was unclear. Combined imaging and spectroscopy with the EPIC X-ray CCDs unequivocally reveals a heavily obscured AGN and a separately identified thermal (starburst) plasma, in NGC 835, NGC 833, & NGC 839. NGC 838 shows only starburst thermal emission. Starbursts and AGN can evidently coexist in members of this highly evolved system of merged and merging galaxies, implying a high probability for the formation of AGN as well as starbursts in post-merger galaxies.
Original languageEnglish
Pages (from-to)L110-L115
JournalAstronomy and Astrophysics
Publication statusPublished - 1 Jan 2001


  • galaxies : starburst
  • X-rays : galaxies
  • galaxies : active


Dive into the research topics of 'XMM-Newton first-light observations of the Hickson galaxy group 16'. Together they form a unique fingerprint.

Cite this