ChandraObservations of NGC 4261 (3C 270): Revealing the Jet and Hidden Active Galactic Nucleus in a Type 2 LINER

Abstract

Chandra Observations of NGC 4261 (3C 270): Revealing the Jet and Hidden Active Galactic Nucleus in a Type 2 LINER A. Zezas1, M. Birkinshaw2, D. M. Worrall2, A. Peters3, and G. Fabbiano1 © 2005. The American Astronomical Society. All rights reserved. Printed in U.S.A. The Astrophysical Journal, Volume 627, Number 2 Article PDF View article References Citations 318 Total downloads Cited by 10 articles Turn on MathJax Share this article Get permission to re-use this article Article information Abstract We present results from a Chandra ACIS-S observation of the type 2 low-ionization nuclear emission-line region (LINER) radio galaxy NGC 4261 (3C 270). The X-ray data show that this galaxy hosts a heavily obscured (NH ~ 8 × 1022 cm-2) active galactic nucleus (AGN) with an intrinsic luminosity of 2.4 × 1041 ergs s-1, which dominates the energy output of the nucleus but is much less than the Eddington luminosity of its central massive black hole. The multiwavelength properties of this component are consistent with either radiatively inefficient accretion flows or emission from the inner part of a jet within 20 mas (3.4 pc) from the nucleus. A softer, unobscured power-law component, which we identify as synchrotron X-ray emission related to the unobscured part of the inner jet, produces ~10% of the 0.1-10.0 keV emission from the nucleus and is likely to be associated with the arcsecond-scale optical/UV emission measured with the Hubble Space Telescope (HST). These results indicate that the energy source of some type 2 LINERs could be a heavily obscured AGN, when obscuration of the ionizing continuum might be responsible for the low ionization state of the line-emitting gas.