2003/07/03 by A. Tarchi, C. Henkel, M. Chiaberge +1 · 2 citations
Physics and Astronomy · #Astrophysics and Cosmic Phenomena #Galaxies: Formation, Evolution, Phenomena #Radio Astronomy Observations and Technology #astro-ph
paper · pdf · doi:10.1051/0004-6361:20031062
published as Astron.Astrophys.407:L33-L36,2003 · Four pages. One figure. To be published in Astronomy and Astrophysics Letters
arxiv created 2003/07/03 · openalex publication_date 2003/08/01 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/31
We report the first detection of a water megamaser in a radio-loud galaxy, 3C 403. This object has been observed as part of a small sample of FR IIs with evidence of nuclear obscuration. The isotropic luminosity of the maser is ~1200 . With a recessional velocity of cz ~ 17 680 km s-1 it is the most distant H2O maser so far reported. The line arises from the densest interstellar gas component ever observed in a radio-loud galaxy. Two spectral features are observed, likely bracketing the systemic velocity of the galaxy. These may either arise from the tangentially seen parts of a nuclear accretion disk or from dense warm gas interacting with the radio jets.