XMM-Newton and Chandra observations of three X-ray-faint early-type galaxies

E O'Sullivan, Trevor Ponman

Research output: Contribution to journalArticle

45 Citations (Scopus)


We present XMM-Newton observations of three X-ray-underluminous elliptical galaxies, NGC 3585, 4494 and 5322. All three galaxies have relatively large optical luminosities (log L-B=10.35-10.67 L-circle dot) but have X-ray luminosities consistent with emission from discrete sources only. In conjunction with a Chandra observation of NGC 3585, we analyse the XMM-Newton data and show that the three galaxies are dominated by discrete source emission, but do possess some X-ray-emitting gas. The gas is at relatively low temperatures, kTsimilar or equal to0.25-0.44 keV. All three galaxies show evidence of recent dynamical disturbance and formation through mergers, including kinematically distinct cores, young stellar ages and embedded stellar discs. This leads us to conclude that the galaxies formed relatively recently and have yet to build up large X-ray haloes. They are likely to be in a developmental phase where the X-ray gas has a very low density, making it undetectable outside the galaxy core. However, if the gas is a product of stellar mass loss, as seems most probable, we would expect to observe supersolar metal abundances. While abundance is not well constrained by the data, we find best-fitting abundances
Original languageEnglish
Pages (from-to)535
Number of pages1
JournalRoyal Astronomical Society. Monthly Notices
Publication statusPublished - 1 Apr 2004


  • galaxies : individual : NGC 3585
  • galaxies : individual : NGC 5322
  • X-rays : galaxies
  • galaxies : elliptical and lenticular, cD
  • galaxies : individual : NGC 4494


Dive into the research topics of 'XMM-Newton and Chandra observations of three X-ray-faint early-type galaxies'. Together they form a unique fingerprint.

Cite this