CO OBSERVATIONS OF SOUTHERN S0 GALAXIES

LJ TACCONI*, LE TACCONIGARMAN, M THORNLEY, H VANWOERDEN

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

Abstract

We present the first attempt to measure CO distributions in a number of southern S0 galaxies. In all but two of the 11 galaxies in our sample, we searched for CO emission in several offset positions as well as in the central beam. CO was detected at the greater-than-or-equal-to 3-sigma level in at least one position in six of the galaxies. In NGC 1326 the CO emission is found to be extended beyond the central regions, and has been detected in several positions in the disk. In all of the other galaxies, our data are consistent with the CO emission being partially resolved. However, more recent observations of a second sample of galaxies show extended, resolved CO emission in a few more S0's.

To investigate the gas distributions in these systems we have developed a modeling routine which generates and fits synthetic spectra to the data. In NGC 1326 the best fit indicates that the molecular gas is mainly distributed in a ring which is located approximately 1 kiloparsec from the nucleus of the galaxy. The simple ringed distribution cannot explain all of profile features which are seen along the major axis, however. A zeroth order attempt to include a CO bar in the model did not improve the model fits to the data.

Original languageEnglish
Pages (from-to)541-549
Number of pages9
JournalAstronomy & astrophysics
Volume252
Issue number2
Publication statusPublished - Dec-1991

Keywords

  • GALAXIES, LENTICULAR
  • GALAXIES, STRUCTURE OF
  • INTERSTELLAR MEDIUM, MOLECULES
  • RADIO LINES, MOLECULAR
  • MOLECULAR CLOUD CONTENT
  • H-I-OBSERVATIONS
  • SA-GALAXIES
  • GLOBAL PROPERTIES
  • NEUTRAL-HYDROGEN
  • STAR FORMATION
  • POLAR RINGS
  • CALIBRATION
  • GAS
  • DYNAMICS

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