Discovery of a nuclear gas bar feeding the active nucleus in Circinus

R. Maiolino, A. Alonso-Herrero, S. Anders, A. Quillen, M. J. Rieke, G. H. Rieke, L. E. Tacconi-Garman

Research output: Contribution to journalArticlepeer-review

37 Scopus citations


We report the discovery of gas inflow motions toward the active nucleus of the Circinus galaxy caused by the nonaxisymmetric potential of a nuclear gas bar. Evidence for dust associated with the bar comes from the HST/NICMOS H-K color map, whereas the streaming motions along the gas bar are seen in the velocity field of the H2 S(1) (1-0) emission line. The gas bar is about 100 pc long with a visual extinction in excess of 10 mag. Indication for the gaseous nature of this bar comes from the lack of a stellar counterpart even in the K band, where the extinction is greatly reduced. We also use the NICMOS emission-line images (Paα, [Si VI], and [Fe II]) to study the innermost region of the ionization cones and the nuclear star-forming activity. We discuss the possible relationship of these components with the gaseous bar.

Original languageEnglish (US)
Pages (from-to)219-231
Number of pages13
JournalAstrophysical Journal
Issue number1 PART 1
StatePublished - Mar 1 2000


  • Galaxies: active
  • Galaxies: individual (Circinus)
  • Galaxies: kinematics and dynamics
  • Galaxies: nuclei
  • Galaxies: seyfert
  • Infrared: galaxies

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science


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