4 research outputs found
N(HI) and jet power/emission in AGNs
Neutral hydrogen (HI) 21 cm absorption has been detected against more and
more powerful radio jets. In this work, based on the Guppta et al. 2006a
sample, we present our preliminary study of the correlations between the HI
column density N(HI) and the jet power, N(HI) versus the low frequency
luminosity at 408MHz, and N(HI) versus the radio luminosity at 1400MHz.Comment: 3 pages, 1 figures, Multiwavelength Variability of Blazars Guangzhou,
China, Sept. 22-24, 2010; will be published by JA
Investigation of the obscuring circumnuclear torus in the active galaxy Mrk231
Here we report on observations of powerful hydroxyl (OH) line emissions that
trace the obscuring material within the circumnuclear environment of the galaxy
Markarian 231. The hydroxyl (mega)-maser emission shows the characteristics of
a rotating, dusty, molecular torus (or thick disk) located between 30 and 100
pc from the central engine. We now have a clear view of the physical
conditions, the kinematics and the spatial structure of this material on
intermediate size scales, confirming the main tenets of unification models.Comment: 10 pages, including 3 Figures, published in Nature Vol 421 2003; the
published pdf--file and higher quality images are available at
http://www.astro.rug.nl/~hrkloeck/np/pubmrk231.htm