Home ContactSitemap CAS中文
About Us
Brief Introduction
History
Directors
Organization
Research Groups
Scientific Progress
Seminars
Colloquia
CAS Members
Experts
Faculty
Research Fields
Center for Astro-geodynamics
Center for Galaxy and Cosmology
DRAST (Division of Radio Astronomy Science and Technology )
High Technology Laboratories

Location: Home>Research>Seminars
H2O Maser and a Plasma Obscuring Torus in Radio Galaxy NGC 1052
Author:
ArticleSource:
Update time: 2008-11-28
Close
Text Size: A A A
Print

Speaker: Dr. Satoko SAWADA-SATOH (Department of Physics, Faculty of Science, Yamaguchi Univerity, Japan)

Title: H2O Maser and a Plasma Obscuring Torus in Radio Galaxy NGC 1052

Time: Nov. 28th. 2:00PM

Location: middle conf. room, 3rd floor

Abstract: We present multi-frequency simultaneous VLBA observations at 15, 22 and 43 GHz towards the nucleus of the nearby radio galaxy NGC1052. These three continuum images reveal a double-sided jet structure, whose relative intensity ratios imply that the jet axis is oriented close to the sky plane. The steeply rising spectra at 15-43 GHz at the inner edges of the jets strongly suggest that synchrotron emission is absorbed by foreground thermal plasma.

We detected H2O maser emission in the velocity range of 1550-1850 km/s, which is redshifted by 50-350 km/s with respect to the systemic velocity of NGC1052. The redshifted maser gas appears projected against both sides of the jet, in the same manner as the HI seen in absorption. The H2O maser gas are located where the free-free absorption opacity is large. This probably imply that the masers in NGC1052 are associated with a circumnuclear torus or disk as in the nucleus of NGC4258. Such circumnuclear structure can be the sence of accreting onto the central engine.

Shanghai Astronomical Observatory, All Rights Reserved
80 Nandan Road, Shanghai 200030, China
Tel: +86-21-64386191 Email:shao@shao.ac.cn