Optical structure of a large sample of ultraluminous IRAS galaxies

K. J. Leech, M. Rowan-Robinson, A. Lawrence, J. D. Hughes

Research output: Contribution to journalArticlepeer-review


We present deep images for 34 out of a new sample of 36 ultraluminous Infrared Astronomical Satellite (IRAS) galaxies (ULGs), as well as seven additional high-luminosity objects, selected from the North Galactic Wedge selected area and QDOT all-sky redshift surveys. Previous charge coupled device (CCD) data and Sky Survey material are used in the examination of the two remaining ULGs. All but one of the 43 high-luminosity and ultraluminous IRAS galaxies are classified according to the seven-band system of Lawrence et al., with the exception being unclassifiable due to the proximity of a bright star. Of the total usable sample of 42, we find that 28/42 (67 per cent) are interacting or merging, 4/42 (10 per cent) are in a close pairing but show no obvious signs of an interaction, and 10/42 (23 per cent) are isolated or have only distant companions. Given the clear preponderance of merging systems in infrared-luminous objects, the existence of a substantial fraction of exceptions is interesting. The starburst trigger in these cases is unknown. We discuss spectroscopic data on the galaxies and present new spectra of two objects.
Original languageEnglish
Pages (from-to)253-269
JournalMonthly Notices of the Royal Astronomical Society
Publication statusPublished - 1 Mar 1994


  • Infrared Sources (Astronomy)
  • Interacting Galaxies
  • Luminosity
  • Red Shift
  • Starburst Galaxies
  • Infrared Astronomy
  • Sky Surveys (Astronomy)


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